Lipid profile

How is treatment decided?
Treatment is decided on the basis of the full risk profile (including, as well as the laboratory parameters, age, sex, obesity or overweight, high blood pressure and a family history of cardiovascular disease). A target LDL cholesterol value is set according to the following guidance:

• LDL < 100 mg/dl (2.59 mmol/L) in patients with existing heart disease or diabetes
• LDL < 130 mg/dl (3.37 mmol/L) in the presence of at least 2 other risk factors
• LDL < 160 mg/dl (4.14 mmol/L) with no more than one risk factor

The first step in lowering LDL cholesterol is a radical change in lifestyle: a diet low in saturated fat and regular exercise are very helpful; in some cases, advice from a dietitian or nutritionist may be needed to correct eating habits.

If lifestyle changes are not enough to bring LDL cholesterol down to the target value, medication may be prescribed. There are several classes of cholesterol-lowering drugs; the most widely used are statins. During treatment, blood tests must be carried out periodically to monitor therapy and adjust it if necessary.

What are the other cardiovascular risk factors besides LDL cholesterol?

• Cigarette smoking
• Age > 45 years
• Male sex
• HDL cholesterol < 40 mg/dl in women and < 35 mg/dl in men
• High blood pressure (blood pressure > 140/90 mmHg or taking antihypertensive medication)
• Family history of early cardiovascular disease (a first-degree relative with heart disease at age < 55 for men and < 65 for women)

Note: high HDL cholesterol levels are considered a protective factor, and their presence allows one risk factor to be “cancelled out” when calculating overall risk.

1. I had a total cholesterol test and the result was below 200 mg/dl. Do I also need the other lipid profile tests?
If total cholesterol is below 200 mg/dl and there is no family history of cardiovascular disease, a full lipid profile is not necessary. It may still be useful to test HDL cholesterol as well (many screening programmes now include total and HDL cholesterol); if HDL cholesterol is < 40 mg/dl, a full lipid profile is advisable.

2. How often should the lipid profile be done?
Healthy people with no other cardiovascular risk factors should have their total and HDL cholesterol tested every 5 years. If other risk factors are present, or high cholesterol has already been documented, a full lipid profile needs to be done more often.

3. My lipid profile shows a normal LDL cholesterol but raised triglycerides; why?
High triglycerides with normal cholesterol values are a common finding, mainly in people with type 2 diabetes. However, this can also have technical causes: some laboratories calculate LDL cholesterol indirectly from triglycerides, total cholesterol and HDL cholesterol; this calculation is only reliable if triglycerides do not exceed 400 mg/dl, otherwise LDL cholesterol must also be measured directly to obtain a more reliable value.

4. What are VLDL?
VLDL (very low-density lipoproteins) are a class of lipoproteins. Lipoproteins (HDL, LDL, etc.) are molecular complexes containing proteins, cholesterol, triglycerides and phospholipids in proportions that vary according to the lipoprotein class. VLDL in particular contain mainly triglycerides and proteins. No validated test for measuring serum VLDL is currently available.