A low level of plasma high-density lipoprotein (HDL) cholesterol, "the good cholesterol", is the most common lipid abnormality observed in patients with a premature atherosclerotic cardiovascular disease. HDL carry excess cholesterol from peripheral tissues to the liver to be metabolized or excreted, a process known as reverse cholesterol transport.

Epidemiological studies have shown an inverse correlation between plasma levels of HDL cholesterol and the risk of cardiovascular disease. An increase in plasma HDL cholesterol levels by 1 mg/dL may reduce the risk of cardiovascular disease by 2 to 3%. The standard care of treatment for a low level of HDL cholesterol is: 1) lifestyle modifications including exercise, smoking cessation, weight control, moderate alcohol intake and decreased dietary fat intake - all patients are encouraged to follow these lifestyle modifications; 2) medications which can raise HDL cholesterol.

Currently used medications to treat lipid disorders can increase, in some extent, HDL cholesterol. These include niacin (vitamin B3), fibric acid derivatives (fibrates) and statins. However there is no data on the effect of these medications on severe cases of HDL deficiency. This project aims to determine whether currently available medications, used in standard medical practice for the treatment of lipoprotein disorders, can substantially increase HDL cholesterol in severe cases of HDL deficiencies.