Effect of low-dose niacin on high-density lipoprotein cholesterol and total cholesterol/high-density lipoprotein cholesterol ratio.

Niacin significantly alters blood lipid concentrations but its use has been limited because of clinically disturbing side effects. In an attempt to circumvent these drawbacks, 55 patients with cardiovascular disease were given low-dose long-acting niacin, 1 g/d. Treatment was continued for a mean of 6.7 months and lipid values were compared with a non-treated group of 17 patients followed for a mean of 6.3 months. Lipid values did not change in the nontreated group. In the niacin-treated group total cholesterol and triglyceride levels also did not significantly change. High-density lipoprotein (HDL) cholesterol level rose 31% from 1.01 +/- 0.31 mmol/L to 1.32 +/- 0.31 mmol/L and total cholesterol/HDL cholesterol ratio was reduced 27% from 6.4 +/- 1.9 to 4.7 +/- 1.3. Despite these results, 40% of the patients left the study mainly because of side effects. Apart from one patient who developed overt diabetes, of questionable relationship to niacin, no patient developed serious side effects such as jaundice or peptic ulcer as seen with much higher doses of the drug. Although often difficult to administer to patients, niacin, particularly in low dose, deserves consideration as an inexpensive agent especially useful for elevating HDL cholesterol level and altering the total cholesterol/HDL cholesterol ratio.