When the blood (plasma/serum) total cholesterol level exceeds the normal range (above 200 mg/dl), the condition is called hypercholesterolemia. It literally means high blood cholesterol levels. The most important problem in hypercholesterolemia is a waxy fat deposit (plaque) in the walls of the arteries (atherosclerosis) and subsequent reduction in blood flow.
Cholesterol is often portrayed in a negative light, but it does play important role in the body. In the human body there are different biologically important fatty substances (lipids). Cholesterol just one of these lipids. The important roles of cholesterol in human body are :
- Asa precursor of steroid hormones.
- As an essential part of the cell membrane and thus helping in maintenance and proper functioning of every body cell.
Usually hypercholesterolemia does not produce any symptoms can lead to long term complications which are symptomatic. These complications include :
- Angina chest pain (decreased blood flow to the heart) – ischemic heart disease
- Heart attack (stoppage of blood flow to the heart because of plaque rupture) – Myocardial infarction
- Brain stroke (stoppage of blood flow in vessels of brain)
- Transient loss of vision (due to reduced blood flow in the ocular vessels).
- Deposition of fat over upper eyelid, back of the hand, knuckles, elbow and buttock.
Fats (lipids) are transported in the blood binding with proteins as lipoproteins. Lipids include cholesterol, triglyceride and phospholipid. Different lipoproteins contain different percentage of cholesterol and have different functions. Clinically important lipoproteins are LDL, VLDL and HDL.
- LDL: Known as “bad cholesterol” as high LDL cholesterol is associated with high risk of plaque formation (atherosclerosis), subsequent narrowing of arteries and reduced blood flow.
- HDL: Known as “good cholesterol” because low levels of HDL (< 40mg/dl in men and < 50mg/dl in females) increases risk of heart disease. Females in there reproductive years are usually protected from heart disease because of high level of HDL.
- VLDL: Triglyceride is the major lipid constituent. Sometime patients of hypercholesterolemia also suffer from hypertriglyceridemia.
The reasons why some people suffer with high blood cholesterol and others do not is not always clear despite the presence of the same risk factors being present. It is believed to be largely due to genetic factors. The risk factors for hypercholesterolemia include :
- Obesity (BMI >30)
- High saturated fat rich diet
- Alcohol consumption
- Cigarette smoking
- Drug-induced like with steroids
- Sedentary lifestyle
- Hereditary (heart disease in first degree relatives in men < 55yrs and females < 65 yrs)
- High blood pressure
- Type 2 diabetes mellitus
- Patients on dialysis
Lifestyle changes are recommended for patients with moderately elevated blood cholesterol levels. Even patients on medication for hypercholesterolemia should follow these measures that include :
- regular exercise
- dietary modification (low saturated fat)
- avoiding smoking
- minimal alcohol consumption
These measures are also effective in preventing hypercholesterolemia.
- Statins are the most commonly prescribed drugs that inhibits the synthesis of cholesterol.
- Bile acid binding resins act by binding bile acids and facilitating its excretion via stool. Therefore indirectly the pool of cholesterol is reduced as liver requires increased amount of cholesterol to compensate the excreted bile acid.
- Cholesterol absorption inhibitor prevents intestinal absorption of dietary cholesterol. Maximum benefit is obtained when statins are combined with this group of drugs.
- Niacin and fibric acid derivatives are usually more effective in patients suffering from hypertriglyceridemia.