General Information for Hyperlipidemia

Cholesterol is a lipid (fat) substance that is produced inside the body’s cells and it is used to form parts of cell membranes, whereas it is necessary for the synthesis of some hormones. It is also ingested with foods that contain fat.

There are different types of lipids that all serve as intermediates of the lipid metabolism, i.e. the elimination and use of fat from the body, after it is ingested. These lipid types are cholesterol, lipoproteins (HDL-good cholesterol, LDL-bad cholesterol) and triglycerides. When the lipid levels are increased, then we refer to hyperlipidemia which is the most common form of dyslipidemia (which includes any abnormality in the lipid levels i.e. low HDL-cholesterol and increased LDL-cholesterol).

Dyslipidemia is usually caused by a disturbance in the body’s fat metabolism, that is related to genetic factors, eating and exercising habits and increased body weight. In other cases it is caused by non-lipid disorders, such as insulin resistance, diabetes, hypothyroidism, alcohol consumption, liver disease, nephrotic syndrome, kidney disease, anorexia nervosa and drugs.

Dyslipidemia causes no symptoms.

When lipids in the blood are high, they accumulate along with other substances causing lumps on the lining and inside the wall of the arteries (the vessels that supply the body’s tissues with blood), triggering the beginning of inflammation. This procedure results in progressive thickening of the arterial wall and the creation of the atherosclerotic plaque, which in time causes narrowing of the artery. When the artery becomes so narrow, that is almost occluded, blood flow is compromised and symptoms like angina (heart pain), myocardial infarction (heart attack), leg pain while walking, or stroke may appear.

High cholesterol levels increase the chance of getting cardiovascular disease, like heart attack or coronary artery disease, stroke, or peripheral artery disease which can lead to amputation. The risk is increased if other risk factors like diabetes, high blood pressure, smoking, obesity, and family history are present.

The risk of getting cardiovascular disease in the future ten years can be calculated, by taking into account all present risk factors. Decisions on treatment are taken based on the 10-year cardiovascular risk (http://www.heartscore.org/Pages/welcome.aspx).

Total cholesterol values can serve as predictors of the appearance of cardiovascular disease. Levels below 200 mg/dl are considered normal.

LDL-cholesterol is more accurate in predicting cardiovascular disease. Harmful levels are not the same for every patient and they depend on age, sex and other risk factors, so that lower treatment goals are appointed to patients at higher risk. In general, desirable levels of LDL are < 100mg/dl. Values 100-129 mg/dl are almost desirable, 130-159 mg/dl borderline high, 160-189 mg/dl high and ≥ 190 mg/dl extremely high.

HDL-cholesterol is protective and lowers the risk for heart disease, because it prevents cholesterol from building up in the arteries walls. Values above 40 mg/dl in men and 50 mg/dl in women are desirable.

Very high levels of triglycerides increase the risk of pancreatitis, but they are also related to the appearance of cardiovascular disease if other lipid disorders are present. Desirable levels are < 150 mg/dl.

Non-HDL cholesterol (Total cholesterol – HDL) is a better predictor of cardiovascular disease in diabetic patients and women. Desirable levels are considered those that are 30 mg/dl above the goal for LDL-cholesterol.

A 10% reduction in blood cholesterol in a 40 year old man can cause 50% reduction in the risk for ischemic heart disease in the next 5 years.

• Men >35 years old with no other risk factors for coronary artery disease.
• Men 20-35 years old with other risk factors for coronary artery disease.
• Women >45 years old with no other risk factors for coronary artery disease.
• Women 20-45 years old with other risk factors for coronary artery disease.
• Screening should be repeated every 5 years or in shorter intervals in case of high-normal values.

Traditional risk factors for coronary artery disease are: Smoking, Hypertension, low HDL-cholesterol, family history of early cardiovascular disease (<55 years in first-degree male relative or <65 years in first-degree female relative), increased age (men ≥45 years, women ≥55 years)