Niacin Boosts HDL's ApoA-1 and Decreases LDL's and VLDL's ApoB
Niacin is a B vitamin that, when used at pharmacological doses, has been shown to reduce blood cholesterol and triglyceride levels and the risk of coronary heart disease. The mechanism by which niacin alters levels of cholesterol and triglycerides in the blood is not known. We studied the in vivo mechanism of the effects of niacin on the rate of production and clearance of apoA-I, the major protein component of HDL (also known as good-cholesterol) and of apo-B100 in the VLDL, IDL, and LDL (also known as bad cholesterol) in 5 men with elevated triglyceride and low HDL cholesterol levels. Our study indicates that treatment with niacin causes a 15% increase in plasma apoA-I levels, which is due to a 24% increase in the production of apoA-I. In addition, niacin caused a 21% reduction in plasma triglyceride levels, which was accompanied by reductions in apo B-100 in VLDL and a faster clearance of apo B-100 in VLDL from circulation. Our data indicate that niacin treatment causes beneficial changes in plasma lipoprotein levels: in particular, niacin was associated with significant increases in HDL apoA-I concentrations and production, as well as enhanced clearance of VLDL apoB-100.
Lamon-Fava, S., Diffenderfer, M., Barrett, P.R., Buchsbaum, A., Nyaku, M., Horvath, K.V., Asztalos, B., Otokozawa, S., Ai, M., Matthan, N., Lichtenstein, A.H., Dolnikowski, G., Schaefer, E. Extended-release niacin alters the metabolism of plasma apolipoprotein (apo) A-I- and apoB-containing lipoproteins. Arteriosclerosis Thrombosis and Vascular Biology. 2008 November