To provide a direct comparison of agents that raise plasma levels of high-density lipoprotein cholesterol (HDL-C) to help devise strategies for coronary risk reduction.
In a multicenter, randomized, double-blind trial, we compared the effects of extended-release niacin (Niaspan), at doses increased sequentially from 1000 to 2000 mg at bedtime, with those of gemfibrozil, 600 mg given twice daily, in raising low levels of HDL-C. Enrollment criteria included an HDL-C level of 1.03 mmol/L or less (≤40 mg/dL), a low-density lipoprotein cholesterol level of 4.14 mmol/L or less (≤160 mg/dL) or less than 3.36 mmol/L (<130 mg/dL) with atherosclerotic disease, and a triglyceride level of 4.52 mmol/L or less (≤400 mg/dL).
Among 173 patients, 72 (82%) of the 88 assigned to Niaspan treatment and 68 (80%) of the 85 assigned to gemfibrozil treatment completed the study. Niaspan, at 1500 and 2000 mg, vs gemfibrozil raised the HDL-C level more (21% and 26%, respectively, vs 13%), raised the apolipoprotein A-I level more (9% and 11% vs 4%), reduced the total cholesterol–HDL-C ratio more (−17% and −22% vs −12%), reduced the lipoprotein(a) level (−7% and −20% vs no change), and had no adverse effect on the low-density lipoprotein cholesterol level (2% and 0% change vs a 9% increase). Significance levels for comparisons between medications ranged from P<.001 to P<.02. Gemfibrozil reduced the triglyceride level more than Niaspan (P<.001 to P=.06, −40% for gemfibrozil vs −16% to −29% for Niaspan, 1000 to 2000 mg). Effects on plasma fibrinogen levels were significantly favorable for Niaspan compared with gemfibrozil (P<.02), as gemfibrozil increased the fibrinogen level (from 5% to 9%) and Niaspan tended to decrease the fibrinogen level (from −1% to −6%).
In patients with a low baseline HDL-C level, Niaspan at its higher doses provided up to 2-fold greater HDL-C increases, decreases in lipoprotein(a), improvements in lipoprotein cholesterol ratios, and lower fibrinogen levels compared with gemfibrozil. Gemfibrozil gave a greater triglyceride reduction but also increased the low-density lipoprotein cholesterol level, which did not occur with Niaspan.