Category: Media

Vision 20/20: viewing the world perfectly

AT the dawn of a year and decade, it is fitting to review and renew our goals. 2020 holds special meaning for everyone who appreciates the sense of sight and especially for me as an eye specialist. “20/20 vision” is medical parlance for normal or optimal visual sharpness: what a healthy eye should be able to see clearly, at 20 feet. “Vision 2020: The Right to Sight” is also the name of a World Health Organization (WHO) project that was launched in 1999 as part of an ongoing project commenced 30 years ago, with the aim of eliminating avoidable blindness globally by 2020.

A global guidance and blueprint for eye care systems, Vision 2020 started with advocacy for intervention against eye diseases such as cataract, glaucoma, diabetes, Vitamin A deficiency and trachoma (parasitic river blindness prevalent in Africa) as its first priorities. To sum up Vision 2020, WHO published its comprehensive World Report on Vision last year, freely available on the Internet. Although unmet needs still exist, the project has seen unprecedented progress and is deemed successful by most yardsticks. There has been a very significant reduction in cases of eye infections and blindness from Vitamin A deficiency, as well as the ongoing reduction in prevalence of blindness among adults, including treatable causes.

Nevertheless, continuous focus is necessary as these results can’t keep pace with the growth of an ageing population. The report includes the global magnitude of the issues, successes, what remains to be done, recommended strategies and paths charted for the future. The causes of vision impairment and their impact on financial burden are of particular interest to me. The figures are staggering: at least 2.2 billion people have vision impairment globally. At least one billion of these (an underestimation according to the report) could have been prevented or are unaddressed, with 123.7 million suffering from unaddressed refractive errors.

Cataract comes in second at 65.2 million. These eye conditions are projected to increase due to population ageing, as well as environmental and lifestyle changes. From the report, the cost of the coverage gap for global unaddressed refractive errors and cataract was estimated to be US$14.3 billion. In the world, there are an estimated 2.6 billion people with myopia (of which 312 million are under 19 years old) and 1.8 billion with presbyopia. These contributed to losses in annual global productivity estimated to be US$244 billion and US$25.4 billion, respectively. The prevalence of myopia is the highest in East, South and Southeast Asia. It was reported in these regions that the economic burden of uncorrected myopia was more than double that of other regions and equivalent to one per cent of gross domestic product (GDP).

A simple calculation should convince one of the highly cost-effective outcomes for addressing treatment of myopia, presbyopia and cataract – my three main areas of practice in ophthalmology – in any health care system. There are several points in the report that strike a pertinent yet sensitive note. First, the issue of funding for management of the commonest eye condition, that is, refractive errors, which in many countries are mostly out-of pocket. These include the costs of spectacles, deemed an assistive device, as well as contact lenses and refractive surgeries such as LASIK. Second, the potential role for public-private partnerships to improve eye care services. What is new for this decade is the focus of “integrated people-centred eye care” as a continuum of health intervention.

This is a new addition to the WHO project’s action plan to now include integration of eye care into health care systems, ideally across all sectors, and, for this, four important strategies are proposed. These are to empower and engage people and communities, reorientate model of care, coordinate services within and across sectors, and create an enabling environment. In my mind, these are applicable to both policymakers and the public. Integration of eye care into health care is here to stay. For the general public, it should translate to ensuring good eye care and visual habits from the groundup, starting in the family, schools, public institutions, at work and at leisure.

It also means having eye protection in sports and in relevant occupations and attending eye screenings regularly even when the eyes feel fine, as some eye diseases are silent in the initial stages where they can be controlled and potentially reversed. Ensuring good general health and lifestyle is key in maintaining good eye health. Our eye clinic also welcomes the new decade with an addition of the services provided. Incorporating a Refractive and Cataract Surgery service  on site has long been our aim. We look forward to deliver safe, effective and integrated eye care with the addition of the trusted Johnson and Johnson Star S4 iLASIK excimer laser with FDA approved wavefront guided treatment via its latest iDesign 2.0 and the Swiss-made Ziemer Z8 femtolaser for OCT-guided thin flap LASIK surgery, being the first in Singapore, as well as for laser cataract surgery.

These will help address the most common eye conditions in the world – namely myopia, presbyopia and cataract – in an efficient and affordable manner.
The Ziemer Z8 also looks forward to providing further innovations in flapless refractive lenticule treatment for myopia in the near future. Eye screening enabled with artificial intelligence for front-of-eye diseases by dual-Scheimpflug imaging and back-of-eye diseases by digital angiography and fundal camera remains our go-to option, a sign of the times.

Dr Daphne Han
Senior Consultant Ophthalmologist
MBBS (Melbourne), MMed, MRCS, FRCS (Edinburgh), FAMS

THE BUSINESS TIMES WEEKEND JANUARY 11, 2020

Ready to run on the big day?

Some vital dos and don’ts that will ensure you have a memorable marathon experience

Singapore marathon fever is upon us once again. And it is going be a momentous event for a lot of us. You probably have been training for this for the last few months with building up your weekly mileage, enduring weekly long runs, doing speed work with interval training and, last but not the least, letting your body rest and recover. By this time, you would have scaled back on your training in preparation for the big day. So how tough is it to run a 26-mile race? The first person to run the marathon, a Greek soldier called Pheidippides, collapsed and died. Currently, the best marathoners in the world are invariably the Kenyans; they run the race in a little over two hours. The main fuel to support a marathon comes from glycogen. The main storage of glycogen is in the liver and the muscles which provides enough fuel for about two hours. Hence, if you take more than two hours to run the race, you have to top up your fuel supply, usually by eating.

Fuel for a run commonly comes in the form of bananas, chocolate or energy gels. The energy gels contain carbohydrates in form of maltodextrins and glucose with potassium and sodium. Maltodextrins are long chains of glucose molecules. They are pre-digested simple carbohydrates and resemble the food that has been digested by the stomach. Hence the absorption is rapid in the intestine. These maltodextrins also serve the purpose of being isotonic with little water needed. The thing to remember is that you got to accustom yourself to drinking isotonic fluids while taking these gels on the run prior to the big race. It is recommended for an average runner to take a gel patch every 30-45 minutes in a marathon. The other important thing to consider is your hydration status. You should hydrate yourself adequately during the last week prior to race day. You should, by now, be able to gauge how much fluid you would need during the training runs in the same humidity and temperature. Hence, on race day you would know how to drink appropriately. One should not depend purely on the sensation of thirst before drinking.

Often, when you feel thirsty, the body is already dehydrated. Thirst is regulated by a centre in the brain stem which senses the concentration of the circulating blood. When the blood concentration rises, the brain stem sends a signal to the body giving you a sensation of thirst. This signal is often ignored during a run when there is too much excitement and euphoria. There is also a risk when one drinks too much. This is commonly seen in the slower runners who would be drinking more at water stations and yet sweating less. That can lead to a situation called hyponatremia, where the sodium level in the blood drops due to dilution from over-drinking. This can cause altered mental state and confusion. This brings us to the matter of a runner who collapses during the run; it could be from hyponatremia, heat disorder, low blood sugar or from a heart condition. In our hot and humid climate our major concern is heat disorder.

The temperature in the body rises from dehydration, excessive heat production due to running and the lack of heat dissipation from our warm and humid weather. Heat disorder is quite insidious and must be recognised by the paramedical and medical personnel deployed during the race. The immediate treatment is to get the collapsed heatstroke runner into a body cooling unit before evacuating him to hospital. Wearing the right shoes is important too, and for most of us, cushioning shoes are critical to buffer the constant pounding on the road. Some of us are flat-footed and need motion and stability control shoes. Some runners buy special socks; wearing light mesh clothing is useful in our climate, as well as applying Vaseline to chafing parts of our bodies. Chafing is caused by constant rubbing of the moving body parts against the running gear which causes the bruising of the skin. The common sites are the nipples, the groin and the armpits. The conditioning of the mental state is as important as the physical preparation.

The feeling of not being able to complete the race comes soon after the euphoria during the start of the race has evaporated. This is compounded by the heat, loss of stamina to complete the 26 miles, and low body fuel. Some runners listen to music to distract themselves, carry on a conversation, or merely admire the environment and the cheering crowd. Positive thinking helps tremendously to minimise the awkward feeling of not being able to complete the race. When you have completed the race, head for the medical post if you are feeling unwell. Otherwise, keep moving as there can be risk of fainting due to venous pooling when the overworked muscles suddenly become inactive. Do make sure you drink water and isotonic drinks. When you have reached home, continue to drink water and isotonic drinks and listen to your thirst. Do eat protein-laden and carbohydrate-rich food. You should continue to move around and do get rest, naps and a good sleep to let the muscles and the heart to recover quickly.

Getting yourself a sports massage may also help and do not race competitively for a fortnight or more. If you have injuries, remember to ice, rest, compress and elevate the affected limb. You can take some an anti-inflammatory medication and, if in doubt, go see your family doctor for evaluation. Finally, do go out there today and enjoy your run that you have been training for quite a while. You don’t always have to finish it if you can’t and you don’t have to run it all the way.

Just listen to your body and you will have a great, once-in-a-lifetime experience.

Dr Chong Yeh Woei
Senior Consultant Physician (Internal Medicine)
MBBS (Singapore), MRCP (UK) (Internal Medicine)

THE BUSINESS TIMES WEEKEND 30 NOVEMBER 2019

Guarding against diabetes-linked eye disease

Early and regular eye screening is the best defence for diabetics against loss of vision

Several years ago, while volunteering as a consultant to teach local eye doctors for a charitable organisation in rural China, I was eager to share the strategies applied in healthcare in Singapore against the rise of diabetes mellitus, an increasingly common disease. I believed that our emphasis on public education, early screening and management of diabetes with a view to prevent and delay complications work well. To my fellow ophthalmologists in the Chinese hospitals, I recommended our methods of early and regular eye screening for detection of diabetes- associated eye diseases, such as cataracts, glaucoma and diabetic retinopathy, the latter being an eye disease that affects the retina, the receptors of light at the back of the eye.

For the far-flung corners of the land, I showed them examples of mobile eye screening services, on a bus, that several countries such as Britain and Singapore employ. It was my sincere wish that my suggestions would be heeded by the hospital I visited, as the cases of diabetic eye disease that I witnessed there were very advanced and some beyond hope of repair. And I counted my blessings of being both a provider and user of the Singapore medical system. Let’s refresh ourselves about diabetes and the importance to guard against it. Just two years ago, a single medical condition, diabetes mellitus, was flagged for the first time, to my knowledge, at the National Day Rally by Prime Minister Lee Hsien Loong, as a national priority that needed to be addressed.

Complications

A metabolic disease that affects the control of sugar in our bodies, diabetes can result in complications such as blindness, kidney failure and gangrene, consequently requiring amputations. It also makes diseases like heart attacks and strokes more common. One in nine adults aged 18-69 here suffer from it, and the figure increases in the older age group. Type II diabetes affects the majority of the sufferers especially those over 40 yet is highly preventable by lifestyle modification. It costs taxpayers S$1 billion a year, and the figure is expected to increase yearly.

For my part, where the eyes are concerned, once diabetes has been diagnosed, usually from a referring doctor, it is imperative that the patient begins a lifelong routine of eye screening and examinations. This is so that any diabetes-related eye diseases, particularly diabetic retinopathy, can be detected and treated early. Diabetic retinopathy, a form of microvascular disease, stems from ischaemia (a lack of oxygen supply to the affected tissues), which can eventually result in the sprouting of abnormal blood vessels in the retina and elsewhere.

These abnormal blood vessels tend to bleed and scar, obscuring vision and causing further complications such as raised eye pressure, in a condition called neovascular glaucoma which can result in a painful blind eye, irreversible in its advanced stages. Diabetes can also cause retina detachment, a stage of disease so advanced that even surgery often fails to restore a patient’s sight. Yet other diabetes sufferers lose vision at an earlier stage through diabetic maculopathy, where the macula, an area of the retina akin to its “heart”, becomes swollen. Diabetes, as mentioned above, also increases the likelihood of getting cataracts and glaucoma.

The eye screenings, in the early years of diabetes, may be performed as part of a general health check in clinics equipped with eye photography services (fundal photography), even without doctors on site. This service can be found at many clinics, in the government and private sectors, and is increasingly being introduced into premises such as optical centres. A major trend is for Artificial Intelligence to assist in the interpretation of the images obtained, to reduce redundant clinic attendances.

Once signs of diabetes-related eye diseases are detected, it is important to then present to an eye clinic for further management, which may include more frequent eye examinations or commencement of treatment. Treatment of diabetic retinopathy and maculopathy usually involves firstly managing the underlying diabetes. Strict blood sugar control is vital to stabilising the related eye diseases. Beyond that, either lasers or injections into the eye of a family of medicine called anti-vascular endothelial growth factors (anti-VEGF) are then prescribed. The anti-VEGFs, albeit costly, are wonderful game changers in the treatment of diseases affecting the retina in the past 15 years.

Severe scarring

Without it, many patients would be doomed to blindness. This is due to the fact that despite the effectiveness of retinal lasers in stabilising diabetic retinopathy, they can result in severe scarring that jeopardises vision, a side-effect that can be largely avoided by the anti-VEGF injections. Fast forward to November 2019, and I found myself rather piqued in my eye clinic by a recent case of a patient who consulted me for a second opinion for a cataract operation. The patient’s diabetic eye disease had been up until recently managed by a local tertiary eye clinic. As part of routine pre-operative screening for my patient’s cataract operation, a thorough eye examination and pre-operative tests are compulsory.

For diabetes sufferers, I also highly recommend undergoing a blood test called the HbA1C to check for long-term control of the disease, as poor control of diabetes can complicate the recovery and results of eye surgeries such as for cataracts. For this patient, these tests yielded evidence of mild diabetic retinopathy but under-the-radar sub-optimally controlled diabetes. In this case, the elective cataract surgery is rescheduled pending stabilisation of diabetes by the medical team, a best practice preference.

As an ophthalmologist, I believe that although my focus is on eye care, it is a holistic healthcare that we should aim for, hence the team-based multi-disciplinary approach in my current medical practice. Indeed, the eyes are the windows to our health. Yet, although the eyes don’t lie, even with the sharpest eye, one does need to take a step back to see the full picture.

Here’s to a full picture for all our diabetes patients, with stable, healthy eyes!

Dr Daphne Han
Senior Consultant Ophthalmologist
MBBS (Melbourne), MMed, MRCS, FRCS (Edinburgh), FAMS

THE BUSINESS TIMES WEEKEND NOVEMBER 16 – 17, 2019

Watch that hidden poison in your rice

Besides seafood, rice products have the highest arsenic content. Long-term exposure to arsenic is linked to cancer

Many may be surprised that the large majority of cancers are related to environmental causes and genetic causes comprise a minority. Hence, the air we breathe, the food we eat and the water we drink – they all have a bearing on our health. Rice is a major food staple in this part of the world. Just recently, one of my patients, Mdm A, who had been eating a brand of rice which is less commonly consumed by the public but is available in high end supermarkets, was surprised that after consuming it for one year, her blood arsenic level was significantly elevated.

Arsenic in food: seafood and rice. Arsenic is a naturally occurring metal element that is present in water, air and soil, and is absorbed by some food crops as they grow. The forms of arsenic can be broadly divided into two categories; inorganic and organic. The term organic here refers to the chemical form and not the method of growing rice. While inorganic arsenic is the main toxic form of arsenic, the common form of organic arsenic (predominantly DMA) can also be toxic though organic arsenic compounds are generally considered to be of little toxicological significance.

The highest levels of arsenic are found in fish, crustaceans, and seaweed, but the arsenic is mainly organic and hence considered to have relatively minimal toxicological effect. Seafood aside, rice products have the highest arsenic content. Rice, being grown in flooded soils, is exposed to higher arsenic content in the soil and rice plants have evolved efficient mechanisms of capturing arsenic from soil solution. Hence, rice has higher levels of inorganic arsenic than other cereal foods.

Permissible levels of arsenic

Arsenic is classified by The International Agency for Research on Cancer, the European Food Safety Authority and the United States Food and Drug Administration (FDA) as a carcinogen based on the association between long-term exposure to arsenic with skin, lung and bladder cancers. Studies have linked high chronic (prolonged or long-term) exposure with adverse health effects in multiple organ systems including the stomach, kidneys, liver, and in coronary heart disease and diabetes.

Hence, in April 2016, the FDA proposed a limit of 100 parts per billion (ppb) for inorganic arsenic in infant rice cereal to reduce infant exposure to inorganic arsenic. In January 2016, the European Commission implemented regulations controlling the level of inorganic arsenic in rice products. For example, the inorganic arsenic content in rice destined for the production of food for infants and young children should not exceed 0.1 mg/kg wet weight.

Arsenic content in rice: high levels in rice bran and rice milk

The arsenic content in rice varies according to the type of soil where it is grown, the processing of the rice and the way of cooking the rice. In terms of the source of rice, in a publication in October 2015 in Environmental Science and Pollution Research journal, comparison of arsenic content from different sources of rice grains showed that on the whole, rice grains from United States of America had twice the level of arsenic of rice from Asian countries.

Generally, basmati rice is lower in arsenic than other kinds of rice whereas brown rice has a higher content of arsenic than white. Brown rice is higher in inorganic arsenic than white rice as arsenic is concentrated in the bran that is removed by milling to produce white rice. The amount of arsenic present in rice products also depends on the way the rice product is processed. Rice bran is  composed of the hard outer layers of the rice grain and it contains a large amount of fibre. Although often thought of as a healthy fibre food product, one may be surprised to know that among the rice products, the highest arsenic concentration has been found in rice bran.

Rice cakes and rice crackers are popular snacks but the arsenic content can be higher than that in cooked rice. While consuming rice milk, be aware the arsenic content is higher than the amount that is generally allowed in drinking water. In the United Kingdom, children younger than 4½ years are advised against having rice milk because of arsenic concerns. The US Environmental Protection Agency, the European Union and the World Health Organization have set a level of 10 μg per litre for total arsenic concentrations in drinking water.

Reducing arsenic in rice by soaking

Studies by Mosley and Meharg from the United Kingdom showed that by soaking the rice overnight before cooking, using a ratio of 5 times as much water as rice, only 18 per cent of the arsenic remained in the rice. The time the rice is soaked in water allows the arsenic to leave the rice into the water. The following day, drain the water and rinse the rice thoroughly with fresh water. Add 5 parts of water to each part of rice and cook till the rice is tender. Do not boil the rice till it is dry. Drain the water again and rinse the rice with hot water to get rid of the cooking residual water.

However, if the rice is cooked till there is no more water or it is cooked with a rice cooker, the arsenic is reabsorbed into the rice. If the same ratio is used for cooking but not soaked overnight, 43 per cent of the arsenic remained in the rice.

Putting arsenic in rice in perspective

Before you decide to change to a no rice diet, you should know that the lung cancer and bladder cancer risk attributable to lifetime exposure to all rice products is a small portion of all cases of these cancers, at 39 cases per million people (10 cases/million bladder cancer and 29 cases/million lung cancer). This additional 39 cases are a small fraction of the 90,000 per million people who develop lung and bladder cancer over a lifetime from all causes.

Rice is not the only source of arsenic in food. A 2014 European Food Safety Authority (EFSA) report stated that the main contributor of inorganic arsenic, except for infants and toddlers, was grain-based processed products (nonrice-based). In the ESFA report, other important contributors to the overall intake in all age classes were rice, milk and dairy products and drinking water. Food experts do not consider the consumption of rice products a few times a week a health risk, and rice continues to be a part of the international recommendations on food.

Things to note

Remember the following when making decisions on rice:

  • Do not be fooled by “organic” rice labels – they have no bearing on the arsenic content.
  • White rice has a lower content of arsenic compared to brown rice.
  • Asian sources of rice have lower arsenic content.
  • Young children below 5 years should avoid rice milk and reduce rice-based snacks.
  • Apparently “healthy” rice bran has the highest arsenic content among rice products.
  • Cooking rice the right way can minimise the arsenic to negligible levels.
  • Eating the “right” rice will have no significant adverse impact on your health. Hence, there is no need to give up your chicken rice, nasi biryani and nasi lemak!

Dr Michael Lim
Medical Director
MWH Heart Stroke and Cancer Centre
MBBS, MRCP (UK), M Med (Int Med), FAMS (Cardiology), FRCP (Edin)

THE BUSINESS TIMES WEEKEND 9 NOVEMBER 2019

Not all wheezing is asthma-related

Asthma is a common medical condition affecting the lower respiratory tract. It affects all age groups, genders and is seen globally. It has several causes – namely genetic and environmental factors. However, in the absence of an obvious precipitant, it is often idiopathic (when the cause is unknown). Asthma is characterised by breathing difficulty, often at night and associated with wheezing, shortness of breath (hence its name from the Greek “to pant”), chest tightness and coughing. There are however other medical conditions which present in a similar vein which are characterised by noisy breathing when the patient is awake, strained/rapid breathing (and in severe cases) leading to cessation of breathing and death. Some of these conditions manifest very early in life and others in adulthood.

The aim of this article is to provide the reader with a few causes of breathing problems affecting children and adults that may occasionally be treated as asthma but affect the upper airway as opposed to the lungs.

Anatomy

The airway can be divided into two broad parts – the upper and lower. The upper part provides a common passage for food, fluid and air to pass through the oral cavity (such as from the nose for air) and into the back of the mouth and thereafter into the throat (pharynx). It is at this crossroads that our physiological control mechanisms separate what enters the lungs and what enters the gullet (oesophagus). The upper airway descends into our voice box (larynx) through the windpipe (trachea) and into the lungs which are found within the chest (thorax).

The narrowest portion of the child’s upper airway is just below the vocal folds (level of the cricoid cartilage) and above the start of the trachea while the adult upper airway is narrowest at the level of the vocal folds. The vocal folds are found within the voice box which is a cartilaginous structure comprising a shield-like structure and a complete cartilaginous ring. The level at which the vocal folds are is described as the glottis and following on, the area above the supragottis and below – the subglottis before descending into the trachea (Figures 1 and 2).

Noisy breathing

Not all noisy breathing is wheeze. Narrowing of the lower air passages with a characteristic high-pitched noise due to the vibration of the walls of the partially obstructed “air tubes” is effectively wheeze. A frequently confused sound which arises from laryngeal obstruction is called stridor. This sound is also high-pitched, often higher pitched than a wheeze and can vary depending on the location of the obstruction in the larynx and trachea i.e. being present when breathing in (inspiration), out (expiration) or both.

Another noise which is low-pitched and related to obstruction of air above the voice box, at the level of the back of the tongue or tonsils, is called stertor. These noises are present when the patient is awake, unlike snoring which is low-pitched noisy breathing when asleep.

Childhood conditions

Paediatric causes of breathing difficulties can be congenital and present very early in life. Severe cases of upper airway obstruction can be due to the incomplete canalisation of the tubular structures that eventually become the larynx and trachea. These conditions are rare and the milder forms may not present that early in life and become more evident as the child becomes more active or starts to make noises or speaks. Other conditions affecting the child but not present at birth are acquired and can be due to a variety of causes including infections, tumours, foreign body inhalation and neurological conditions.

Laryngeal webs

Mild laryngeal webs in children may cause noisy breathing which can be confused for a wheeze. As the child grows, parents may notice that their child has a hoarse voice and on exertion starts to “wheeze”. Mild laryngeal webs can be asymptomatic and go unnoticed for years, while more severe ones will manifest earlier. Surgery in symptomatic cases is the treatment of choice and is generally successful.

Laryngeal papillomatosis

Recurrent respiratory papillomatosis (RRP) is a viral infection of the upper airway – most commonly involving the voice box but occasionally the trachea and rarely (but potentially fatally) – the bronchioles (lung air passages). It is caused by the human papilloma virus (HPV) which causes skin warts and other tumours such as the cancers of the female cervix and palatine tonsil. The condition affects both adults and children although the disease profile is somewhat different with remission generally a feature in the childhood form. Despite this, many children with this condition can be misdiagnosed for having noisy breathing commonly ascribed to wheezing and if associated with a hacking cough – to croup (laryngotracheobronchitis).

Recalcitrant “wheeze” with hoarseness in children should therefore be a consideration for specialist ENT referral to assess the airway. Treatment of RRP can be fraught with multiple operations to reduce the bulk of viral growths and restore the airway while making every effort not to cause damage to the vocal folds that are very delicate and scarring of the airway.

Adult conditions

Unlike childhood causes of laryngeal obstruction, most adult onset upper airway conditions are acquired. Throat cancer is often seen in smokers and when tumours of the larynx narrow the air passage, the ensuing “noise” can be mistaken for a lower airway pathology. Operations to the thyroid, carotid arteries and upper spine can affect the nerves (causing various degrees of paralysis) that control the movement of the vocal folds and may be subtle – only becoming evident if a co-existing problem such as a throat infection worsens the airway resulting in noisy breathing/stridor. Here are some other interesting causes that may be mistaken for asthma:

Exercise-induced laryngeal obstruction

This condition is seen in young adults who are usually involved in high intensity sporting activities or exercise. The attacks of noisy breathing and breathlessness only come on when performing certain tasks but otherwise the subject is well when not under such duress. The confusion with asthma is common and diagnosis in subjects who already have asthma – difficult. Special investigations including a real-time examination of the patient’s larynx (continuous laryngoscopy examination, CLE) with a flexible nasendoscope while performing the said exercise is indicative but, in many instances, impractical.

Idiopathic subglottic stenosis

This condition is characterised by a deposition of scar tissue in the region of the subglottis below the true vocal folds and above the start of the trachea. It is almost exclusively seen in Caucasian women and is, as the name implies, of unknown cause. Treatment options include minimally invasive “closed” techniques which are performed through the nose using flexible endoscopes.

Conclusion

Upper airway narrowing in the context of the voice box and windpipe can be confused with asthma and leads to delays in the diagnosis and subsequent management of the root cause. It is worthwhile reconsidering whether patients who have been erroneously diagnosed with asthma really suffer from this condition. Recalcitrant cases or cases where two or more co-existing pathologies are present should be referred on to ENT surgeons for the necessary investigations and management promptly.

Dr Vyas Prasad
Senior Consultant Otolaryngologist Head and Neck Surgeon
MB BCh BAO BA (Dublin), MSc DIC (London), DLO (England), MRCS (Edin), FRCS (ORL-HNS)(Edin), FICS

THE BUSINESS TIMES WEEKEND, OCTOBER 19-20, 2019

Safeguarding your eyes from the ‘thief of sight’

Glaucoma is a silent disease, and opportunistic screening and regular monitoring are recommended to detect it early

The recent haze ended as quickly as it began and the skies in Singapore are blue again. In medical parlance, such episodic problems are usually termed an “attack”, such as a heart attack, a gout attack or more relevant to my profession, a glaucoma attack. After each annual episode of “haze attack”, our region seems to bounce back, finger-pointing subsides and life returns to normalcy, until the attack repeats again the following year.

However, unlike the haze, human organs once “attacked” usually decline in function, causing ill-health that may become irreversible to the point of demise. A glaucoma attack is an acute disease that the eye may suffer from, which can be associated with irreparable damage. For the uninitiated, glaucoma is a group of eye diseases typically characterised by elevated eye pressure, loss of field of vision and a classic glaucomatous appearance of the eye nerve ending, visible only through an examination of the back of eye.

Field of vision is a concept that warrants explanation to many people. Each eye has its own field of view – the area that it can see – and in combination they provide comprehensive navigation of our environment. A minimum visual field criterion denoted as at least 120 degree of angle horizontally with either single or both eyes is legally required for driving.

Mixed bag of subtypes

As a disease, glaucoma comprises a mixed bag of subtypes, arising from various causes. These may be as innocent as being born with the genes for glaucoma whose effect manifests as one age, or simply being anatomically predisposed. It may arise as an association of general diseases such as diabetes or as a side effect of prolonged use of steroid medications. It may even be a result of other local eye diseases such as ischaemia (a lack of oxygen), inflammation or injury.

What ties these various subtypes together is the ultimate destiny of the eye nerve: that there is thinning and loss of the nerve cells as a result of the eye pressure, which in some cases may be deceptively normal on measurement but high for the individual eye nerve  (to each eye nerve its own eye pressure, so to speak). Unchecked, glaucoma can surreptitiously lead to irreversible blindness.

By year 2020, as the third leading eye disease, it will affect an estimated 80 million people worldwide. Of these, 3.2 million is estimated to be blind from glaucoma. Being the top irreversibly blinding eye disease, public education of glaucoma is one of the leading ophthalmic priorities. Nevertheless, compulsory glaucoma screening has not been deemed cost-effective in public health policies worldwide. Opportunistic screening is hence the usual approach.

In general, glaucoma is divided into two broad categories based on the shape of the outflow apparatus of the eye (yes, there is a plumbing system in the amazing design of the human eye). These two categories are the open angle type versus the closed angle type. Although the open angle variety is commoner worldwide, closed angle glaucoma has a higher incidence in East Asians and Caucasians compared to Africans, due to racial differences and anatomical features.

Both types are silent diseases, with few warning signs of the loss of field of vision, hence nicknamed “the thief of sight”. However, the closed angle variety of glaucoma is notorious for being associated with episodes of not-so-silent attacks during which the eye pressure becomes acutely elevated due to vicious cycles of outflow blockage within the eye. During an attack, one would experience a red, painful and blurry eye, often with severe accompanying headache, nausea and vomiting, so much so that confused sufferers had on occasions been misdirected to the gastroenterology department for the prominent symptoms suspicious of a stomach flu.

Disclaiming any intended ageism and sexism, the classic scenario of an attack of angle closure  glaucoma is of a little old lady watching television at night: advanced age, being female and in the dark are indeed risk factors, although televisions are commonly swapped for mobile phones these days. While the management of an acute attack of glaucoma is considered a gift question in the eye specialty board examinations, real life cases are not as straightforward.

After a glaucoma attack is “broken” or stopped, much else needs doing, including prevention of recurrence, repairing sight and safeguarding the fate of the fellow eye. Ramifications affect the front and back of the eye as the high pressure affects them all. Closely associated with vascular diseases, glaucoma has a higher incidence in those who suffer poor circulation in the extremities (cold hands and feet). A big drop in night-time blood pressure, snoring or sleep apnoea are possible contributors too.

Certain yoga postures involving inverse poses were documented to be associated with elevated eye pressures (particularly the sirsasana pose), hence glaucoma-sufferers should consider modifications to these poses. In terms of treatment of glaucoma, there are roles for topical eyedrops, laser   treatments and surgical therapies, with recent advances in minimally-invasive glaucoma surgery, all of which target lowering of the eye pressure to halt progression of visual field loss.

Preventive care

However, the mantra remains “prevention is the best medicine”. Opportunistic screening and regular monitoring are highly recommended particularly when there is a positive family history or significant risk factors. Detection of strong signs of suspicions of glaucoma is followed by management strategies unique to each subtype of disease. Preventive treatment involving lasers and surgeries such as early cataract extraction is recommended for closed angle glaucoma.

The latter represents a shift in management strategies as a result of large-scale multinational studies conducted in the recent years, and is believed to be a more cost-effective treatment to lower the risk of an attack. As I resign myself to the high probability of a repeat haze “attack” next September, I find solace in the thought that in healthcare, active steps can be taken by the individual to prevent acute phases by monitoring and managing chronic conditions, in an evidence-based manner, before devastating problems arise.

The best defence may indeed be a good offence, in the form of an eyecheck, for a start!

Dr Daphne Han
Senior Consultant Ophthalmologist
MBBS (Melbourne), MMed, MRCS, FRCS (Edinburgh), FAMS

THE BUSINESS TIMES WEEKEND, OCTOBER 12-13, 2019

Should I Eat More Fish?

Beyond just eating fish, it is also important to understand what fish to take, how it should be cooked and the quantity that should be consumed. Among the fatty acids that are present in seafood, the long-chain n-3 polyunsaturated fatty acids (P3UFAs), namely, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are the PUFAs most closely associated with heart health. The content of these 3PUFAs vary with the type of seafood, the highest content being seen in coldwater fatty fish such as salmon, anchovies, herring, mackerel, tuna and sardines. One fatty fish serving of about 100 gm per week provides the recommended daily intake of 3PUFAs. Other types of seafood such as shrimp, lobster, scallops, tilapia, and cod have lower levels of 3PUFA.

Currently, supermarkets stock a wide variety of foods enriched with 3PUFAs including eggs, peanut butter, orange juice, margarine, bread, yogurt, and milk. However, seafood remains the only class of food which has been researched extensively. Presently, the 2015-2020 Dietary Guidelines for Americans and the Scientific Report of the 2015 US Dietary Guidelines Advisory Committee recommend at least two servings per week to provide a daily average of 250 mg of 3PUFAs per day in place of other animal sources of protein.

Effect of 3PUFAS in studies

Ingested seafood-derived 3PUFAs eventually become part of the cell membranes and have been shown to have favourable physiological effects on the electrical activity of the heart cell membrane which make the cell “less irritable” and more electrically stable. Hence, adequate consumption of seafood has also been associated with positive clinical findings such as lower heart rate, slower conduction of electrical impulses between the upper and lower heart chambers, lower likelihood of abnormal recovery of the electrical activity of the heart muscle cell and less heart rate variability.

The combined effects contribute to more stable heart muscle cell electrical activity and have been associated with a lower risk of developing life-threatening heart rhythms and sudden heart-related deaths. Studies have shown that 3PUFA intake is associated with improvement in the elasticity of arterial walls and lower arterial stiffness. Seafood-derived 3PUFAs have been shown to reduce serum triglycerides (TG) concentrations in those with high serum triglycerides, most likely by increased liver removal of TG and reduced liver production of TG rich protein particles VLDL (or very low-density lipoprotein).

Preventing sudden heart death

Many studies including the Physicians’ Health Study have shown that while diets high in seafood 3PUFA have not been associated with prevention of heart attacks, there is a strong inverse association with sudden cardiac death. A possible explanation of this is the association of 3PUFA intake with reduction in life-threatening heart rhythms which can occur after a heart attack. Higher seafood intakes have been associated with greater electrical stability of the heart muscle cell, decreased risk of fatal and non-fatal ventricular arrhythmias (abnormal heart rhythm originating from the lower heart chambers), lower heart rate, and improved heart rate variability, each of which is a risk factor for sudden heart death.

It does not mean that the higher the intake of seafood 3PUFA, the lower the risk of sudden cardiac death. While there is an incremental risk reduction benefit seen in those with increasing intake of seafood, this risk reduction plateaus. Hence, while consuming up to 2 fatty fish meals per week is associated with a 50 per cent lower risk of sudden heart death compared with little or no seafood intake, no further reduction was seen with higher intake. Beyond the quantity of seafood consumed, the method of cooking also affects the benefits. While seafood 3 PUFA intake was associated with reduction in sudden cardiac death, this benefit was not seen when the fish was fried. While the studies showing a reduction of sudden heart death with seafood 3PUFA intake were mainly studies conducted in the United States, other studies done in Japanese populations have failed to demonstrate this benefit. One explanation could be that the baseline dietary seafood intake is much higher and 95 per cent of adults eat seafood more than once weekly.

Coronary heart disease

Many large studies reported that increased seafood and dietary 3PUFAs intake was associated with a lower risk of heart artery disease in a healthy cohort. In studies in which all participants in the study reported on their seafood intake, participants who consumed seafood at least four times a week had a 22 per cent lower risk of heart artery disease, compared with those who consumed seafood less than once a month. In addition, the risk reduction could potentially be greater if the seafood intake replaced processed meat. This is illustrated in two large US cohorts, where substitution of 3 per cent of total protein calories in processed meat with 3 per cent of total protein calories from seafood was associated with 31 per cent lower risk of cardiovascular death.

Stroke

Results from the various prospective studies which examined the relationship between seafood 3PUFA intake and stroke have shown that intake of seafood was associated with a lower risk of thrombotic (due to occlusion of artery) stroke but has no association with haemorrhagic (due to bleeding)  stroke. One study which examined the way the fish was cooked, Cardiovascular Health Study, found that while intake of broiled and baked fish was associated with a 40 per cent lower risk of ischaemic stroke, intake of fried fish or fish sandwiches was associated with a higher risk of ischemic stroke. Recent analysis of combined studies has suggested that consumption of one serving of seafood a week was associated with a 14 per cent lower risk of ischaemic stroke compared with no or infrequent consumption of seafood.

Mercury

Large fish such as shark, swordfish, golden bass, king mackerel, tuna, marlin, and orange roughy are a significant source of methylmercury. While current evidence does not show any adverse impact on heart disease, it is possible that high mercury levels can negate the effect of seafood 3PUFAs intake. In a Finnish study of 1,857 men, a 0.5 per cent increase in blood 3PUFAs was associated with a 23 per cent lower risk of sudden heart death among men with low hair mercury but this did not translate to any benefit for men with high hair mercury.

The current evidence suggests that the benefits of one to two servings a week outweigh the risks of methylmercury, especially if a variety of seafood is consumed. However, caution should be exercised against consuming multiple servings of seafood which may potentially contain mercury, as higher fish intake does not translate to further risk reduction as the benefits plateau and have a threshold beyond which there is no incremental benefit.

Conclusions

Current evidence supports the following conclusions:

* Consumption of non-fried seafood with high 3PUFA, one to two times per week is associated with a reduction in the risk of sudden heart death, heart artery disease and ischaemic stroke;

* The beneficial effects of seafood 3PUFA peaks at about 250mg of seafood intake per week and higher intakes are generally not beneficial or harmful.

* There may be further beneficial risk reduction if the seafood is substituted for unhealthy meats such as processed meats.

Coldwater fatty fish such as salmon, anchovies, herring, mackerel, tuna and sardines have distinct benefits Should I eat more fish? The long-chain n-3 polyunsaturated fatty acids (P3UFAs), namely, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are the PUFAs most closely associated with heart health.

 

Dr Michael Lim

Medical Director, MWH
Heart Stroke and Cancer Centre
MBBS, MRCP (UK), M Med (Int Med), FAMS (Cardiology), FRCP (Edin)

THE BUSINESS TIMES WEEKEND, SEPTEMBER 28-29, 2019

What you should know about the various types of vaccines

Travellers especially should take precautions and depending on their destinations, go for the relevant vaccinations

I am often asked about vaccines by my patients; most of the queries pertain to travel, dengue, pneumonia and shingles.

It is interesting to note that most of our childhood vaccines are not compulsory under our laws in Singapore. I had always assumed that vaccines like BCG, polio, hepatitis B, pertussis (whooping cough) are mandatory but only diphtheria and measles are compulsory by law. I believe most parents in Singapore are very compliant with the National Childhood Immunisation Schedule.

In fact, childhood vaccinations have a long history in Singapore. Most people don’t realise that Singapore was one of the first nations in the world to start mass polio vaccination in 1958. We were also one of the first nations to start a mass hepatitis B vaccination programme for all newborns in 1987. As a result, we have managed to cut transmission of Hepatitis B from mother to child by 80 per cent or more. Some of the vaccines are not in the National Immunisation schedule and I am often asked about them. The rotavirus vaccine is for diarrhoea in infants and it is an oral vaccine so there is ease of administering the vaccine. The cost maybe a little daunting though.

The chickenpox vaccine is also useful as chickenpox scars can be quite traumatic for teenagers and everyone does not realise that as an adult, getting shingles is no laughing matter. I am often also asked about the vaccine for cancer of the cervix for young girls. This vaccine is now recommended in the National Schedule. I encourage my patients to send their young daughters for the vaccine as that would prevent cancer of the cervix. The best age would be before they become sexually active; the recommended age would be from 9 years of age onwards. Another vaccine that is quite unusual in the local context – except for people going for the Haj – is the meningitis vaccine. Most of the time, I am asked about this by parents when their child is going to university abroad especially in Europe, USA or Australia/New Zealand. The usual vaccine is called MenAWCY that protects against four strains or serogroups of bacteria identified by the letters.

Increasingly I am also asked by concerned parents about the meningitis B vaccine. At the moment on the CDC Atlanta website, there are three universities in the US that have outbreaks of meningitis B. Apparently there are quite sizeable populations in Western countries carrying the meningitis B strain especially in the varsity age groups. Approximately half of the meningitis cases in the Western world are now caused by this strain.

Another big group of patients are business travellers. A well-paying job in Singapore these days involves a lot of travelling in the region as companies expand overseas. I encourage business travellers to get the influenza vaccine annually. Sometimes the whole family shows up for vaccination prior to a holiday at year end to a winter destination.

This is sadly because they previously had a whole vacation ruined because they caught the flu bug.

Yet other travellers are encouraged to update their Hepatitis A and typhoid vaccines. They are both oralfecal in transmission. Hepatitis A can be quite debilitating, and the natural course may run for up to eight weeks.

Some patients may feel very fatigued for up to six months thereafter. Typhoid fever can be persistent and sometimes diagnosis is delayed; ultimately typhoid can be life threatening. The vaccines are tolerable and there is an oral and injectable typhoid vaccine.

Some of my patients get a fever with the typhoid injectable vaccine but it is usually resolved quickly with paracetamol. As for Hepatitis A, we can also test if the patient is protected against the virus with a simple blood test. About half of those aged 50 and above have natural immunity.

Some of my travellers ask me about tetanus. Most of us have been vaccinated against tetanus in childhood, hence the protection is good enough for a decade till the age of 21 years old. We are actually not worried about stepping on a rusty nail, but whether a wound is dirty. Animal bites are probably the worst and if one fell into a filthy drain, one should get a booster too. A good alternative to the tetanus vaccine is the combined tetanus, diphtheria and pertussis (whooping cough) Tdap vaccine. There is a resurgence of pertussis which is responsible for 10 per cent of emergency room patients presenting with cough.

As for animal bites, I caution travellers not to play with cats, dogs or monkeys when abroad. Singapore is rabies free but the surrounding countries are still endemic for rabies. When bitten abroad, the rabies vaccines and antibody shots should be administered immediately and are both costly and involve multiple injections.

Sometimes, patients ask me about Japanese B encephalitis. This is a disease with high fatality, but you need a mosquito to bite an infected pig and then transmit it to man. Since we have phased out pig farms in Singapore, it is very rare. We would recommend vaccination if one is travelling to certain endemic countries and staying for more than a month in a rural setting. In our local context, there is always the threat of dengue despite our world class mosquito control programme. In dengue infections, we are very concerned if there is a huge viral load coupled with an overwhelming response from the immune system of the patient. This often leads to severe dengue or dengue shock.

The current thinking is that we should vaccinate patients who had dengue previously. The data shows that if we vaccinate dengue-naïve patients; the body becomes primed for severe dengue illness when the infection does occur. In my older patients, I am often asked about pneumonia vaccines and shingles vaccine. The pneumonia vaccines are very useful. There are two available: one covers 13 strains (conjugate PCV13) and the other covers 23 strains (polysaccharide PPV23) of the bacteria that causes pneumonia. We recommend that all above the age of 65 years be vaccinated with both vaccines.

We usually advise that the patient be vaccinated with the conjugate vaccine first followed by the other vaccine a year later. This is to avoid the two vaccines affecting each other’s efficacy. Incidentally the conjugate vaccine is given to children under our national immunisation schedule.

Finally, we have shingles, which is a painful ordeal for patients. Some patients have it on their face and suffer a great deal. There is always the risk of post-shingles pain (post-herpetic neuralgia) that can go on for years. The pain has been known to drive patients to suicide.  The current single dose vaccine is available to those 50 years and older. A newer two-dose shingles vaccine offers very high efficacy, but it is not available yet.

A final word about the naysayers of vaccines; this is also known as vaccine hesitancy. There are many complex reasons for vaccine hesitancy; and social media and Dr Google have not been helpful. There are also the controversies such as Hepatitis B vaccine and multiple sclerosis in France in the 90s and the association of the MMR (measles, mumps and rubella) vaccine and autism. These have been found to be false but the damage has been done. There has been a drop in the coverage of the MMR vaccine in the US and UK with a rise in measles cases worldwide. There is an ongoing measles outbreak in the US originating in the orthodox Jewish communities in New York since October last year. The city has passed a law that prohibits exemptions from vaccines on non-medical grounds. This law will affect 26,000 school-going children in New York. Thankfully in Singapore, vaccine hesitancy has not been a big issue as our population believes that vaccines are safe, effective and necessary.

Dr Chong Yeh Woei
Senior Physician (Internal Medicine)
Singapore Medical Specialists Centre
MBBS (S’pore), MRCP (UK) (Internal Medicine)

The Business Times Weekend, 21 September 2019

Age-related hearing loss has wider ramifications

Age-related hearing loss has wider ramifications

The Impact of hearing loss on health Issues such as cognition and dementia should be recognized and managed

Hearing loss affects an estimated 5 percent of the world’s population, and will affect twice that number (900 million) in 30 years. The majority of these will be adults and especially the elderly because of the declining population (in the developed world) with increasing longevity.

Besides the obvious disability that hearing loss is associated with are other equally compelling health issues that are important to recognise, prevent or manage. Cognitive impairment, dementia, depression and social isolation are several of the conditions that are associated with hearing loss in the elderly.

The aim of this article is to explain the fundamentals of the ear, mechanisms of hearing and the causes of hearing loss in the elderly briefly. Thereafter, a discussion on the impact of hearing loss on cognition and dementia is provided with ways of delaying these conditions.

Anatomy

The human ear consists of three parts, the external, middle ear and inner ear. The external and middle ear are air-filled, while the inner ear lies within the substance of the side bone of the skull – the temporal bone. The ear drum (tympanic membrane) separates the external ear from the middle. The Eustachian tube connects the front of the middle ear to the back of the nose.

Besides the three smallest bones of the human body – the malleus (hammer), incus (anvil) and stapes (stirrup) – the middle ear also contains important nerves that control facial movement, taste and salivation.

The inner ear has two main parts, the bony outer part and soft (membranous) inner part. Fluid bathes these two parts and important receptors for balance and hearing are activated according to the stimuli that reach them. Similarly, the nerves of balance and hearing pass back into the skull where they connect to the brainstem and brain.

How we hear

Sound is a form of energy created by cyclical compression and rarefactions (decompression) of any medium it travels through and is transmitted as waves across different media – air being the most obvious. As the waves pass by, they enter the ear canal cause the intact ear drum to vibrate and transmit the energy to three small bones in the middle ear – a purely mechanical process that aims to increase the efficiency of sound transmission.

This mechanical process transfers to the inner ear via the flat footplate of the stapes bone into the inner ear’s membranous part. Movement of this fluid excites specialized cells with hairs on their end changing their properties and causing the movement of charged electrical atoms, thereby generating electric current that flows in the nerve of hearing to the brain.

Assessing hearing loss

Hearing is assessed in several ways. History taking and examination can provide some clues as to how poor the patient’s hearing can be. Genetic causes, medication, trauma, noise exposure and infection can all affect hearing. Simple clinical assessment in the form of free field hearing tests provide quick and fairly useful information of the hearing capacity. Tuning forks are also used to assess hearing loss and whether or not it is related to conduction of sound through the external and middle ear (air conductive hearing) or to the nerve of hearing (sensorineural hearing).

Formal hearing assessment (eg. a pure tone audiogram) is done in a soundproof room and assesses the ability to hear pure tones (pitches / frequencies) at different sound levels)

Speech audiometry is performed in cases where hearing loss is severe to profound and when the subject is not benefiting enough from hearing aids. Other tests measure the compliance of sound energy transfer from external ear to the middle.

Finally, “electrical” testing of the inner ear and brain can be done to objectively assess hearing where the other “subjective” tests cannot provide an accurate gauge of the hearing loss.

Severity of hearing loss

Sound is measured using a special scale called the decibel (dB) scale. It is a mathematically derived scale and ranges from -10dB to 120dB in most settings. If the sound level at any frequency is 20dB or less (i.e. -10dB to 20dB), it is normal. The other categories are: mild hearing loss (20dB – 40dB), moderate (40dB – 70dB), severe (70dB – 90dB) and profound – any value beyond that. The World Health Organization defines a disabling hearing loss as any hearing above 40dB in adults and 30dB in children.

The ageing ear

As we age, it may seem unsurprising that our ears age too – the nerves of hearing and balance deteriorate due to “unavoidable” wear and tear.

The difficulty however is predicting who, why and when this process affects and whether or not it is purely a function of chronology. For example, not all individuals at 80 years are profoundly deaf, while some patients present at 50 and are already showing signs of severe hearing loss.

Ageing does need not be the single critical factor in what is often attributed as “age-related” hearing loss. Reduced blood flow to the brain, genetics, medication and other neurological conditions may have  an impact on hearing.

Mild cognitive impairment and dementia

By 2050, an estimated 131.5 million patients worldwide will have dementia. Recent studies have shown that cognition is significantly poorer in individuals with untreated hearing loss.

Hearing loss has been consistently shown to be associated with increased risk of developing dementia in the western world but the link with mild cognitive decline has yet to be established given the paucity of work in this regard.

The Singapore Longitudinal Aging Study is a multi-centre project involving several key opinion leaders who have varied backgrounds including ENT surgery and Gerontology / Geriatric Medicine (ref. Heywood and Ng). This study includes nearly 2,600 subjects and a follow up of eight years and has established that like the West, the Asian population is affected equally vis-a-vis cognitive impairment in hearing impaired subjects.

Treatment options

The results of the aforementioned study suggest several treatment options. Hearing aids have been the mainstay of treatment but in cases where they are clearly unhelpful given the severity of the loss, a speech audiometry may demonstrate that the patient, despite being “aided”, is still missing out on a lot of the sound stimuli.

Only 4.3 percent of 50- to 59-year-old and 22.1 percent of those above 80 years with hearing impairment wear hearing aids in the US.

Lack of awareness, stigma, persistently high cost and lack of reimbursement by insurance companies all contribute to the poor uptake of hearing rehabilitation.

In some cases where conventional hearing aids do not help, cochlear implantation is recommended. Cochlear implants have become more accessible and are being recommended to older patients with severe to profound hearing loss that need not affect all the hearing frequencies.

Given that hearing rehabilitation may slow down the progress of dementia and cognitive decline, recommendation for hearing rehabilitation should be made.

Conclusion

Hearing loss in the elderly has ramifications beyond just day to day sound perception and conversation. The increased cognitive load required to process sound in individuals with hearing loss may direct the innate cognitive resources away from centres for memory processing to centres for speech perception.

A focused approach to the elderly with this condition is essential in promoting health, social well-being and reducing cognitive decline and dementia.

Business Times
14-15 September 2019

Are fish oil supplements good for heart?

Are fish oil supplements good for the heart?

Their role in today’s medical context is still not clear

A very common question asked of me by patients is, “Should I consume fish oil supplements?” The fish oil supplements referred to are those containing the omega-3 poly unsaturated fatty acids (PUFA), namely eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).

In this article, recent scientific data will be reviewed to help shed some light on this topic. The scientific data in this article refers to studies on fish oil supplements in the form of capsules and not fish oils from dietary seafood. Firstly, is fish oil supplementation useful for those with no pre-existing heart disease? In the general population for those without pre-existing heart disease, there is presently no evidence that consumption of omega-3 PUFA supplements is beneficial. Even for those with diabetes mellitus or prediabetes, none of the well-designed randomized controlled trials (RCTs) have been able to demonstrate that consumption of omega-3 PUFA supplements can prevent cardiovascular events (heart attacks and strokes).

Secondly, is fish oil supplementation useful for those with no known heart disease, but who were considered at high risk of heart disease on the basis of the presence of disease in other arterial sites such as stroke, limb arterial disease, diabetes mellitus, or hypercholesterolemia?

Overall, the data from RCTs is mixed although the majority of co-authors of the April Omega-3 Polyunsaturated Fatty Acid (Fish Oil) Supplementation and the Prevention of Clinical Cardiovascular Disease Science Advisory from the American Heart Association concluded that treatment is not indicated, a minority of co-authors concluded that treatment of these patients is reasonable.

Can fish oil supplements prevent heart disease and sudden death in patients with heart artery disease?

There are five large RCTs and other smaller RCTs which have been performed to evaluate the effects of omega-3 PUFA supplementation on clinical cardiovascular events in patients with pre-existing heart artery disease. Taken together, the cumulative findings from RCTs suggest that omega-3 PUFA supplements may reduce incidents of heart artery disease death, possibly through a reduction in sudden death during a heart attack. However, fish oil supplementation does not prevent future heart attacks. Hence, it is considered that treatment with omega-3 PUFA supplements is reasonable for secondary prevention of death from heart artery disease.

If your heart pump is weak, current data suggests that omega-3 PUFA supplementation may reduce heart failure-related hospitalizations and death. This conclusion is based on one RCT, and more studies will help to provide more understanding in the future.

However, before you start loading yourself up with large amounts of fish oils, you should be aware that the benefit of fish oil supplementation have decreased over time.

While earlier studies have shown a large reduction in sudden cardiac death, later studies have shown no benefit. This discrepancy may be due to a few factors. Firstly, the relationship between fish oil supplementation and sudden cardiac death is not a linear relationship. In other words, it does not mean that the higher the quantity of fish oils consumed, the lower the risk of sudden cardiac death.

Therefore, in more recent years with more public educations, there has been increasing intake of fish oils. It may be possible that patients included in the more recent trials have already been consuming sufficient amount of dietary fish oils (for, example, at least one to two weekly servings of fatty fish) so that additional fish oil supplementation would produce little or no incremental reduction in cardiac death.

Secondly, medical treatment of heart disease has improved significantly over the years and with optimal medical treatment with current drugs, it may be possible that fish oil supplementation has little benefit whereas fewer patients in earlier trials received cholesterol-lowering medication or had angioplasty or surgery after a heart attack.

Thirdly, given the improvement in medical treatment of heart disease over the last two decades, it has required a much larger cohort of patients to be included in trials to be able to detect the lower incidence of death from heart artery disease. Compared to post-heart attack patients 20 years ago, the likelihood of sudden cardiac death following a heart attack in present day patients is very much lower.

Hence, it is difficult to have a large trial, given the much lower incidence of sudden cardiac death presently, which is able to detect any potential effect of fish oil supplementation on sudden cardiac death.

What this means is that for those patients with heart artery disease who received optimal medical therapy in today’s medical context, the role of fish oil supplements is not entirely clear. However, results of ongoing trials may provide an answer in the near future.

Can fish oil supplements prevent stroke?

For healthy individuals with no prior stroke, there is currently no evidence that the consumption of omega-3 PUFA supplements can prevent strokes. There is currently also no RCT that has examined the effects of omega-3 PUFA supplements on cardiovascular events, either stroke or heart disease, among patients with a  previous stroke.

Mechanisms

The benefits of omega-3 PUFAs in reducing sudden cardiac death is seen in those with a recent heart attack. It is believed that the mechanism is mainly through stabilizing the electrical milieu of the heart muscle cells in the context of a recent heart attack and hence reducing the likelihood of life-threatening heart rhythms.

In a heart attack, there is damaged heart muscle and also heart muscle which is not getting adequate blood flow as a result of occlusion of the heart artery. This causes the affected heart muscle cells to be electrically unstable and this may result in the occurrence of life-threatening heart rhythms originating from the damaged muscle.

It is believed that fish oils work by making the covering membrane of the affected heart muscle cells less irritable and decreases the likelihood that life-threatening heart rhythms may develop. The mechanism of reducing cardiac death by fish oil consumption is not due to effects on atherosclerotic (vascular degeneration) progression of the heart artery, plaque (cholesterol deposits in the wall of the artery causing narrowing) stability, plaque rupture, or the development of a blood clot which occludes the narrowed heart artery segment.

Practical measures

If you are healthy, there is no benefit in fish oil omega-3 PUFA supplements. Even if you have pre-existing diabetes or prediabetes but have no known heart disease, there is no evidence that consumption of fish oil omega-3 PUFA supplements can help.

For those with no known heart disease but are considered at high risk for heart disease on the basis of the presence of disease in other arterial sites such as stroke, limb arterial disease, diabetes mellitus, or hypercholesterolemia, although the majority view is that it is not indicated, there is a small dissenting minority which holds the view that it is reasonable to consume fish oils.

If you had a recent heart attack or have heart failure with reduced heart pump function, omega-3 PUFA supplementation may be reasonable. However, if you are taking omega-3 PUFA supplementation to prevent a future stroke, there is currently no evidence to support it.

If you should decide to take fish oil omega-3 PUFA supplements, it is best to take those with high EPA and DHA content.

Business Times
31 August 2019