Tuesday, April 17, 2012
Malaysia - Controlling the cholesterol phenomenon
The mysterious visage of Mona Lisa - one of the main reasons why this magnificent 16th-century piece of art still reigns as one of the most famous artworks in the world - shows signs that the model in the oil painting suffered from xanthelasma, a subcutaneous accumulation of cholesterol and a build-up of fatty acids just under the skin.
In possibly the most unflattering diagnosis for one of history's most enchanting beauties, Prof Vito Franco, a medical professor who also studies artworks, claimed that he spotted clear signs of the condition in the hollow of Mona Lisa's left eye, as well as evidence of a fatty tissue tumour (lipoma) on her right hand.
The model is thought to be Lisa del Giocondo, a member of a Florence family, who married a cloth and silk merchant.
Unfortunately, at the time Leonardo Da Vinci painted Mona Lisa, millions of men and women over the age of 40 were routinely dying of heart attacks; no one talked about how unusual those early deaths were.
They needlessly perished because the role of cholesterol in causing atherosclerosis and heart disease was not recognised then.
It was not until 1984 that the medical establishment formally recognised the relationship between high cholesterol and heart attack incidence.
"I will never forget, as a teenager, seeing a televised debate between two prominent cardiologists.
"Cardiologist Dr Pritikin explained how reducing an individual's LDL (bad) cholesterol could reverse coronary atherosclerosis, whereas the other cardiologist ridiculed the notion," recalls Prof Dr Sim Kui Hian, president of the National Heart Association of Malaysia (NHAM).
"I knew little about heart attacks back then, other than the fact that my family members and neighbours were having them on a regular basis.
"I also witnessed the poor diets and lifestyles that these heart attack victims partook."
Fast forward to today, the mere mention of cholesterol is sufficient to send shudders down one's spine and can strike deep fear into the heart of a person.
However, this is clearly not the case of fear of the unknown.
Various stakeholders and policymakers have painstakingly and incessantly drummed into all of us that high cholesterol levels, also known as hypercholesterolaemia, reflects an unhealthy condition, as it is the chief risk factor for cardiovascular disease (CVD) - the leading cause of death in Malaysia for the past three decades, and also accounts for nearly 50 per cent of deaths in both the developed world and in developing countries.
"Knowledge is supposedly power, but this seems to be the case of defying gravity!" laments Prof Sim.
Figures from the recently concluded 2011 National Health and Morbidity Survey (NHMS) simply affirm his frustrations.
Malaysians suffering from hypercholesterolaemia had increased drastically from 20.7 per cent in 2006 (NHMS III) to 35.1 per cent in 2011; simply put, that is now one out of three Malaysians.
Prof Sim explains that perhaps the rising prevalence could be attributed to the fact that the focus of hypercholesterolaemia has always been on the prevention aspects or death statistics.
In other words, there has not been enough information regarding the biochemistry surrounding how cholesterol works in our system or wreaks havoc in our bodies.
In conjunction with the NHAM's Annual Scientific Meeting 2012, Fit4Life obtained an update on the battle against hypercholesterolaemia in an interview with three cardiologists and key opinion leaders from the association: Prof Sim, Tan Sri Dr Robaayah Zambahari and Datuk Dr Khoo Kah Lin.
What is cholesterol and how does cholesterol work in the body?
Prof Sim: The word "cholesterol" comes from the Greek word chole, meaning "bile", and stereos, meaning "solid, stiff".
Now, this calls for my infamous liver-lubricant theory!
Let me begin with some preliminaries. Well, cholesterol may have a bad rep, but this waxy-like substance produced by your liver may not necessarily be a deadly poison; instead, it is an extremely crucial and critical compound needed for your normal body functioning, i.e. to enable the production of hormones, Vitamin D and bile acids that aids in the digestion of food in your intestines.
Imagine cholesterol as being so important that the body has the ability to produce it, in case we do not get enough of it with food.
Depending on how much of it we get with food, our body regulates its own production to keep everything functioning properly.
It is also your best friend in case you have a stressful lifestyle.
Cholesterol is the five-star general leading the army when it comes to combating stress.
It is also important for combating cellular damage, which increases as we age.
Now, cholesterol acts like a lubricant in your body.
As you know, oil and water can never mix. However, your body is made up of 70 per cent water, so then, what happens to the fats or oil that you consume?
In this case, cholesterol is there to ensure that the fats or oil you eat becomes soluble or "dissolves" in the water environment of your blood.
Fats like trans-fat or saturated fat are termed "stubborn fats", as those are extremely hard on your system to dissolve.
In turn, your liver has to work overtime to produce more of this lubricant (cholesterol) to dissolve these types of fats, and this increases the amount of cholesterol in your bloodstream.
Dr Robaayah: Think of your gifts - gifts are gifts, but it is the packaging that indicates their difference.
Similarly, cholesterol is cholesterol, but it is carried in the blood in three different "packagings" called lipoproteins, which is any compound containing both lipid (fat) and protein.
You have the LDL or low-density lipoprotein, HDL or high-density lipoprotein, and triglycerides.
The body actually uses the lipoprotein cholesterol as a kind of bandage to cover abrasions and tears in damaged arterial walls, just as it does for any other wound.
Can you tell our readers what a healthy cholesterol level is?
Prof Sim: The definition of a "healthy" level of cholesterol has been repeatedly adjusted during the past 30 years.
Cholesterol can be both good and bad as our individual biochemistry allows for a wide range of cholesterol levels.
However, not many know that what is more important than total cholesterol is your relative quantities of HDL (good) cholesterol in comparison to LDL (bad) cholesterol.
Essentially, you need to ensure that your HDL cholesterol levels stay high, and your LDL cholesterol levels stay low, relative to each other.
Dr Khoo: LDL cholesterol is a major risk factor for heart disease. As such, it is the main focus of cholesterol-lowering treatment.
Your target LDL number can vary, depending on your underlying risk of heart disease.
Most people should aim for an LDL level below 3.4 mmol/L (130 mg/dL).
If you have other risk factors for heart disease, your target LDL may be below 2.6 mmol/L (100 mg/dL).
If you're at very high risk of heart disease, you may need to aim for an LDL level below 1.8 mmol/L (70 mg/dL). In general, the lower your LDL cholesterol level is, the better.
We have National Cholesterol Education, or NCEP, guidelines for where your HDL should be.
What we look for in the HDL guidelines - and these are from the American Heart Association and the American College of Cardiology - is for men to have HDL above 40, and for women, it should be above 50.
Studies have shown that for every 1 per cent that you raise your HDL cholesterol, there's a 2-3 per cent reduction in cardiovascular risk for heart attacks and strokes.
Say a 50-year-old man's HDL is 36. We get it up to 40, which is about a 10 per cent increase. That would translate to a 20 per cent reduction in risk.
What should our readers know about high cholesterol levels (hypercholesterolaemia)?
Prof Sim: Hypercholesterolaemia has become the dominating health concern of the 21st century.
It is actually an invented disease that doesn't show up as one.
Even the healthiest people may have elevated serum cholesterol, and yet their health remains perfect.
But they are instantly turned into patients when a routine blood test reveals that they have a "cholesterol problem".
Symptoms of high cholesterol do not exist alone in a way a patient or doctor can identify by touch or sight. That is why the cholesterol issue has confused millions of people.
Symptoms of high cholesterol are revealed if you have the symptoms of atherosclerosis, a common consequence of having high cholesterol levels.
For instance, the patient may experience leg pain when exercising, due to the narrowing of the arteries that supply the leg, and/or may exhibit signs of xanthomas.
In your clinical experience, is there a particular similarity or trait amongst your pool of patients?
Dr Robaayah: These medical conditions are known to cause LDL levels to rise.
They are all conditions which can be controlled medically (with the help of your doctor, they do not need to be contributory factors):
- High levels of triglycerides
- Kidney diseases
- Liver diseases
- Underactive thyroid gland
The available data suggests that the correlation between elevated cholesterol and coronary disease holds true for all ethnic groups, including Asians and eastern Europeans.
As people in developing societies attain a more affluent lifestyle and change their dietary habits accordingly, the incidence of hypercholesterolaemia and coronary heart disease (CHD) both rise significantly.
The treatment of hypercholesterolaemia has changed drastically over the years. What sort of intervention do you usually first recommend?
Dr Robaayah: Based on the National Cholesterol Education Program (NCEP) and Malaysian Clinical Practice Guidelines (CPG) for the Treatment of Dyslipidaemia, you're considered to be at a high risk of heart disease if you have:
- Diabetes (now, diabetes is categorised as a "heart disease-risk equivalent", i.e, the same 10-year CHD risk as people with known CHD)
- A previous heart attack/stroke
- Artery blockages in your arms or legs (peripheral artery disease)
- Artery blockages in your neck (carotid artery disease)
However, if you happen to have two or more of the following risk factors, that might also place you in the very high risk group:
- Suffering from hypertension
- Low HDL (good) cholesterol
- Family history of early heart disease
- Age older than 45 if you're a man, or older than 55 if you're a woman
According to the updated NCEP Adult Treatment Panel (ATP) III endorsed by the National Heart, Lung, and Blood Institute, the American College of Cardiology, the American Heart Association, and the Malaysian CPG, the intensity of treatment for hypercholesterolaemia should be guided by the patient's risk, which depends on the LDL cholesterol level, the number of CVD risk factors, and whether CVD is already present.
More aggressive interventions are recommended for patients at high risk, than for patients at lower risk.
There is no logic in waiting for a heart attack to occur before starting statin therapy.
It is a proven fact that changes in diet and lifestyle habits alone can only reduce your LDL cholesterol levels by 20 per cent at most.
Although the cornerstone of treatment for patients with elevated cholesterol levels will always be diet and exercise, for most people, statins can be a critical adjunct therapy for those identified to be at high or medium risk of heart disease.
For this, statin drugs are best known for their cholesterol-lowering properties, particularly in LDL cholesterol reduction.
The notion is simple: high cholesterol levels are associated with heart disease and stroke. Drugs that lower cholesterol figure to reduce heart disease.
For statin drugs, this hypothesis has been proved correct - but most clearly for patients that already have heart disease or are at high risk for heart disease (see risk classification above).
Simply put, statins are probably the most important pill a patient with heart disease can take.
For these high-risk patients, the secondary prevention effects of statins are remarkable.
Based on a post-hoc review of the major statin trials, the NCEP ATP III recently concluded that in high-risk persons, the recommended LDL cholesterol goal is less than 100mg/dL, but when risk is very high, an LDL cholesterol goal of less than 70mg/dL is a therapeutic option.
Dr Khoo: The recommendations of ATP III should not override a clinician's considered judgment in the management of individuals.
The guideline is designed to guide clinical decision-making for most patients, but not all patients fit the risk assessment.
When LDL-lowering drug therapy is employed in high risk or moderately high risk persons, it is advised that intensity of therapy be sufficient to achieve at least a 30 per cent to 40 per cent reduction in LDL cholesterol levels.
Moreover, any person at high risk or moderately high risk, who has lifestyle-related risk factors (e.g. obesity, physical inactivity, elevated triglycerides, low HDL cholesterol, or metabolic syndrome) is a candidate for Therapeutic Lifestyle Changes (see TLC works) to modify these risk factors, regardless of LDL cholesterol level.
If, after at least six weeks of dietary therapy and exercise, the reduction in LDL cholesterol levels is inadequate (or if the LDL cholesterol level rises above the level at which drug therapy is indicated), the addition of drug therapy to dietary therapy should be considered.
One of the huge cardiology stories in the past decade has been treatment of elevated cholesterol with 'statin' drugs. Do they have effects beyond simply lowering cholesterol?
Dr Khoo: Yes, there is a particular statin (rosuvastatin) which can help slow the progression of atherosclerosis, which is the build-up of plaque in the artery walls.
Some statins can even increase HDL cholesterol slightly, especially at the highest doses.
However, prescribing a statin might undermine the patient's own efforts in adhering to a TLC plan. For example, some patients derive a false sense of security that because they are taking a statin, they can eat whatever they want, and do not have to exercise.
There has been huge debate over the exact dose of statins a physician should prescribe to patients. What is your take on that?
Dr Robaayah: Generally, start at the lowest dose possible. This is also taking into account the cost factor!
In Malaysia, treatment for a year with atorvastatin 80mg daily costs RM3,139 (S$1,280), which is one-sixth of the annual Malaysian gross domestic product per capita of RM18,734.
Thus, only a small minority can afford this treatment, while the public health system would be bankrupt if it were to provide high-dose statins for all patients who might benefit from it.
It does not mean the higher the statin dose, the likelihood that it will reduce your cholesterol is greater.
For instance, at the 10mg dose of rosuvastatin, the average LDL cholesterol reduction was found to be 46 per cent in one trial.
The Star/Asia News Network
This article is supported by Astra Zeneca, in conjunction with the 14th NHAM Annual Scientific Meeting.