The best agent for increasing HDL cholesterol is ?

Ans. is'b' i.e., Nicotinic acid Nicotinic acid (Niacin) There are three main type of lipases related to metabolism of lipoproteins ? Lipoprotein lipase- Present in blood vessels and causes hydrolysis of tryglyceride content of VLDL and chylomicrones. Hepatic lipase - Conves IDL to LDL by hydrolysing the triglyceride content of IDL. Hormone sensitive lipase - Present intracellularly in peripheral tissue and causes intracellular lipolysis by hydrolysing triglycerides. Niacin (Nicotinic acid) inhibits intracellular lipolysis by inhibiting hormone sensitive lipase- intracellular FFA to liver- triglyceride synthesis. Niacin also increases the activity of lipoprotein lipase- T hydrolysis of VLDL triglyceride. Nicotinic acid also reduces the production of VLDL in liver by inhibiting TG-synthesis - indirectly the VLDL degradation products IDL and LDL are also reduced. Nicotinic acid is the most effective drug to raise HDL-CH. Increased HDL is due to interference of direct pathway of HDL cholesterol to liver which involves apo-A,- Niacin decreases apo-A, mediated hepatic clearance. Nicotinic acid is used in type I, III, IV & V hyperlipoproteinemias.