Hypercholesterolaemia

Cholesterol is a fat-like substance made in the liver and other cells in the body.  It is also found in certain foods, such as meats, dairy products and eggs.  Whilst the body does need some cholesterol for proper functioning, too much of it causes health problems such as coronary heart disease.

The screening, prevention and treatment of hyperlipidaemia is of great importance as it is a major risk factor for Coronary Heart Disease (CHD). CHD has become a major health problem facing communities in the developed world.  In Singapore, CHD is the leading cause of death, second only to cancer.

The Role of Lipids In Coronary Heart Disease

1.  Total Cholesterol: The risk of CHD begins when Total Cholesterol levels rise above 150 mg/dL (3.9 mmol/L), and this risk escalates sharply when Total Cholesterol exceeds 200 mg/dL (5.2 mmol/L). The type of cholesterol which is most significant, is the LDL-cholesterol (“bad cholesterol”) component.

2.  LDL-cholesterol: Too much of LDL-cholesterol causes development of atherosclerotic deposits in the walls of arteries, thus increasing the risk for cardiovascular disease and stroke.

3.  HDL-cholesterol: Commonly referred to as the “good cholesterol”, it has a powerful protective effect against CHD. One should aim to increase HDL levels via exercise and moderate alcohol intake. Obesity, smoking and a sedentary lifestyle all decrease HDL levels.

4.  Triglycerides: The association between Triglycerides and CHD is less well established, however, their levels should be controlled in patients with diabetes and high CHD risk.

 

Risk Factors for Coronary Heart Disease (CHD)

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The risk factors for coronary heart disease include the modifiable risk factors (ones which we can do something about), and the non-modifiable risk factors (ones which we can do nothing about).

 

Classification of Dyslipidaemias

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Dyslipidaemias may be inherited (if you have a positive family history of hyperlipidaemia, your risk for developing it increases) or acquired (through unhealthy lifestyle choices).

There are also some conditions which can secondarily increase cholesterol levels. These include conditions such as diabetes mellitus, chronic renal failure, hypothyroidism, nephrotic syndrome, pregnancy, alcohol abuse, cholestasis and certain drugs (eg. Beta-blockers, corticosteroids, diuretics, oral contraceptives).

 

Screening for Hypercholesterolaemia

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Screening for Total Cholesterol and HDL-cholesterol can be done without fasting. If total cholesterol levels are found to be raised, then you should have your blood tested for Triglycerides and LDL-cholesterol after a fasting period of between 10 – 12 hours.

The following groups should get tested:

• Patients with diabetes

• Patients with CHD, strokes or peripheral artery disease

• Those with a strong family history of hyperlipidaemia

• Those with other risk factors for CHD

• Those having general health screening done

 

Risk Assessment & Hypercholesterolaemia Treatment Goals

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If you are found to have high cholesterol levels, your doctor will assess your risks and discuss with you if treatment is required.  He will generally make his recommendations based on the following:

1. Risk Assessment:

(A) Is there presence of Coronary Heart Disease or “CHD risk equivalent” diseases (i.e strokes, peripheral artery disease, abdominal aortic aneurysm and diabetes mellitus)?

(b) Are there 2 or more risk factors?

The following are risk factors that modify LDL-cholesterol goals:

• Cigarette smoking

• Hypertension

• Low HDL-cholesterol levels (<1.0 mmol/L or < 40 mg/dL)

• Age (men > 45 years, women > 55 years)

• Family history of premature CHD

 

2. Determine LDL-Cholesterol Goal Based on Risk Assessment:

• CHD or CHD Risk Equivalent: LDL goal < 2.6 mmol/L (100 mg/dL)

• > 2 Risk Factors: LDL goal < 3.4 mmol/L (130 mg/dL)

• 0 – 1 Risk Factor: LDL goal < 4.1 mmol/L (160 mg/dL)

 

Lifestyle Changes in Managing Hypercholesterolaemia

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Making health lifestyle changes is an integral part of lipid management.

• Weight reduction if overweight

• Stop cigarette smoking

• Aerobic exercise at least 3-4 times a week – this lowers LDL, triglycerides and raises HDL

• Dietary:

(i) to lower Total Cholesterol and LDL cholesterol:

- reduce intake of fats, saturated fats and cholesterol-rich foods

- increase proportion of monounsaturated and polyunsaturated fat intake

(ii) to raise HDL-cholesterol:

- there is data to suggest that red wine and dark chocolate help raise HDL levels.

• Alcohol restriction in patients with high triglyceride levels.

 

Medication for Hypercholesterolaemia

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The various medication used in treatment of the different types of dyslipidaemia are listed below according to their effects on the different lipid sub-types.

Drug	LDL-Cholesterol	HDL-Cholesterol	Triglycerides
Stains	Lowers by 18-55%	Raises by 5-15%	Lowers by 7-30%
Resins	Lowers by 15-30%	Raises by 3-5%	-
Fibrates	Lowers by 5-25%	Raises by 10-20%	Lowers by 20-50%
Nicotinic acid	Lowers by 5-25%	Raises by 15-35%	Lowers by 20-50%

 

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Further Reading

 
The article above is meant to provide general information and does not replace a doctor's consultation.
Please see your doctor for professional advice.