Gaps in Singaporeans' knowledge about cholesterol

SINGAPORE - A sobering new study has found that close to half the population here has high cholesterol, which puts someone at risk of heart disease and stroke. But what is more worrying is that more than a third of those with high cholesterol, 36 per cent, did not know they had high cholesterol.

Among those who did know, only 39 per cent were on cholesterol-busting drugs.

These findings, published in local medical journal Annals Academy Of Medicine last August, examined 5,083 people aged 24 to 95 from 2004 to 2007.

The study, conducted by seven doctors from the National University of Singapore's Yong Loo Lin School of Medicine, Duke-NUS Graduate Medical School, Singapore General Hospital and Khoo Teck Puat Hospital, was funded by the Biomedical Research Council and pharmaceutical company Pfizer.

Associate Professor Tai E Shyong, head of endocrinology at the Yong Loo Lin School of Medicine and one of the study authors, said the findings signalled that the public should learn more about their cholesterol targets and be more aware of how cholesterol-lowering medication can help them.

High cholesterol is one of several risk factors for cardiovascular disease, a leading cause of death worldwide. In Singapore, heart disease was responsible for one in three deaths in 2010.

This is believed to be the first such study which, instead of a one-size-fits-all approach, used each participant's global cardiovascular risk score to calculate his cholesterol goals. The score determines a person's cholesterol goals based on factors such as age, gender, ethnic group, smoking habit and blood pressure, which are known to be linked to the condition.

This information is then used to track the burden of high cholesterol in Singapore.

So the higher a person's risk of the disease, the lower would be his goal for low-density lipoprotein (LDL), or "bad" cholesterol. For instance, someone who has heart disease is classified as "high risk" and would need to keep his LDL cholesterol under 100 milligrams per decilitre (mg/dL), whereas someone of lower risk would have a target of under 160mg/dL.

The study grouped participants in four risk categories and found that a greater proportion of those in the higher risk categories were unable to reach their LDL goals, even with medication.

The reasons are unclear, but Prof Tai said it could be due to patients not taking cholesterol medication regularly and at the right dosage.

Overseas studies have shown that only half of people prescribed statins (a common class of cholesterol-lowering drugs) stick with them.

Prof Tai believes that misconceptions could have something to do with this.

Some answers may be gleaned from a separate study done last year by the Singapore Heart Foundationand sponsored by Anglo-Swedish drug-maker AstraZeneca.

It found that most of the 300 respondents - 85 per cent - believed Western medication to be effective in controlling high cholesterol. This is considerably more than the 72 per cent who thought so when the same study was conducted back in 2009.

The jump is even bigger for those who consider Chinese or herbal medicine to be effective in taming cholesterol - from 52 per cent in 2009 to 71 per cent last year.

And in both studies, the respondents rated diet and exercise as the most effective measures in managing cholesterol.

Unfortunately, they are somewhat misguided, said Prof Tai.

Medication is the essential third leg of a three-pronged approach - diet, exercise and drugs - which is necessary for people whose cholesterol levels cannot be adequately controlled by lifestyle modifications alone.

Prof Tai, who was not involved in the Singapore Heart Foundation study, said a person's LDL can drop by 30 per cent after using statins for eight to 12 weeks.

By contrast, an overweight person who loses five per cent to 10 per cent of his weight can reduce his LDL by only a mere 8 per cent to 12 per cent.

In any case, losing weight to control cholesterol is "not a strategy for people with acceptable weights", he said.

Respondents in the Singapore Heart Foundation survey also rated kidney and liver problems as their main concerns when taking Western medicine. But kidney problems that arise from taking statins are rare, affecting fewer than one in every million patients, said Dr Low Lip Ping, chairman emeritus of the Singapore Heart Foundation.

This is rhabdomyolysis, the breakdown of muscle fibres that leads to the release of a protein, myoglobin, into the bloodstream, causing kidney damage.

Other studies have also not shown any detrimental effect of statins on the liver.

Mr Tay Chong Chek, a 60-year-old retiree, has been taking statins since his cholesterol diagnosis in 1990.

It was only 13 years later, in 2003, that he was able to change his lifestyle habits, which then helped to bring his cholesterol levels under control.

The former general manager of a manufacturing company said that with less stress at work, he was able to exercise and watch his diet.

Unfortunately, by then he also had diabetes, high blood pressure and coronary artery disease, which needed an angioplasty, so two stents could be inserted to open his blocked arteries.

Mr Tay said he now prefers to eat meals prepared by his wife, also 60. He plays golf, works out in the gym and takes regular walks with his dog.

He encourages others to persevere with lifestyle changes and to continue taking their medication, so as to keep their cholesterol levels in check.

Get a copy of Mind Your Body, The Straits Times or go to for more stories.