VERY HIGH HDL CHOLESTEROL LEVELS - BOON OR BANE

A 50 year old patient cam to Sampurna Sodani Diagnostic Clinic, Indore for routine tests including CBC and Lipid profile. CBC was WNL while chol (211 mg/dl), Triglyceride (109 mg/dl) and HDL was unusually high (113 mg/dl). On further investigations and detailed history it was found that he was a farmer, was nonalcoholic, non-diabetic, normotensive, nonsmoker and had not received any medications for reducing his lipids . He had never undergone any blood tests previously. He complained of headache off and on for which a CT scan was performed and which revealed focal area of hypoattenuation in right anterior centrum semiovale, corona radiate and right lentiform nucleus suggestive of recent right MCA territory infarct. High density lipoprotein or HDL is often called the good cholesterol. It has long been accepted that the HDL is more tightly controlled by genetic factors than are the other lipoproteins (ie, LDL, VLDL, intermediate-density lipoprotein [IDL], and chylomicrons). For example, in certain families, especially some families with Japanese ancestry, a genetic deficiency of cholesteryl ester transfer protein (CETP) is associated with strikingly elevated HDL cholesterol levels. However, environmental factors also have a significant impact on HDL levels. Factors that elevate HDL concentrations include chronic alcoholism, treatment with oral estrogen replacement therapy, extensive aerobic exercise, and treatment with niacin, statins, or fibrates. On the other hand, smoking reduces levels of HDL cholesterol, while quitting smoking leads to a rise in the plasma HDL level. Very high levels of HDL cholesterol have been reported to be atherogenic. The mechanism of this paradoxical effect is not entirely clear.