JAMA 2000 Sep 13;284(10):1263-70 (ISSN: 0098-7484)
Elam MB; Hunninghake DB; Davis KB; Garg R; Johnson C; Egan D; Kostis JB; Sheps DS; Brinton EA
Division of Clinical Pharmacology, University of Tennessee, 874 Union Ave, Memphis, TN 38163, USA.

CONTEXT: Although niacin increases low levels of high-density lipoprotein cholesterol (HDL-C), which frequently accompany diabetes, current guidelines do not recommend use of niacin in patients with diabetes because of concerns about adverse effects on glycemic control; however, this is based on limited clinical data.

OBJECTIVE: To determine the efficacy and safety of lipid-modifying dosages of niacin in patients with diabetes.

DESIGN AND SETTING: Prospective, randomized placebo-controlled clinical trial conducted in 6 clinical centers from August 1993 to December 1995.

PARTICIPANTS: A total of 468 participants, including 125 with diabetes, who had diagnosed peripheral arterial disease.

INTERVENTIONS: After an active run-in period, participants were randomly assigned to receive niacin (crystalline nicotinic acid), 3000 mg/d or maximum tolerated dosage (n = 64 with diabetes; n = 173 without diabetes), or placebo (n = 61 with diabetes; n = 170 without diabetes) for up to 60 weeks (12-week active run-in and 48-week double-blind).

MAIN OUTCOME MEASURES: Plasma lipoprotein, glucose, hemoglobin A(1c) (HbA(1c)), alanine aminotransferase, and uric acid levels; hypoglycemic drug use; compliance; and adverse events, in patients with diabetes vs without who were receiving niacin vs placebo.

RESULTS: Niacin use significantly increased HDL-C by 29% and 29% and decreased triglycerides by 23% and 28% and low-density lipoprotein cholesterol (LDL-C) by 8% and 9%, respectively, in participants with and without diabetes (P<.001 for niacin vs placebo for all.) Corresponding changes in participants receiving placebo were increases of 0% and 2% in HDL-C and increases of 7% and 0% in triglycerides, and increases of 1% and 1% in LDL-C. Glucose levels were modestly increased by niacin (8.7 and 6.3 mg/dL [0.4 and 0.3 mmol/L]; P =.04 and P<.001) in participants with and without diabetes, respectively. Levels of HbA(1c) were unchanged from baseline to follow-up in participants with diabetes treated with niacin. In participants with diabetes treated with placebo, HbA(1c) decreased by 0.3% (P =.04 for difference). There were no significant differences in niacin discontinuation, niacin dosage, or hypoglycemic therapy in participants with diabetes assigned to niacin vs placebo.

CONCLUSIONS: Our study suggests that lipid-modifying dosages of niacin can be safely used in patients with diabetes and that niacin therapy may be considered as an alternative to statin drugs or fibrates for patients with diabetes in whom these agents are not tolerated or fail to sufficiently correct hypertriglyceridemia or low HDL-C levels.

JAMA. 2000; 284:1263-1270.

Extended-release niacin vs gemfibrozil for the treatment of low levels of high-density lipoprotein cholesterol. Niaspan-Gemfibrozil Study Group. Arch Intern Med 2000 Apr 24;160(8):1177-84 (ISSN: 0003-9926) Guyton JR; Blazing MA; Hagar J; Kashyap ML; Knopp RH; McKenney JM; Nash DT; Nash SD [Find other articles with these Authors] Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA. [email protected].

OBJECTIVE: 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.

METHODS: 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 (< or =40 mg/dL), a low-density lipoprotein cholesterol level of 4.14 mmol/L or less (< or =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 (< or =400 mg/dL).

RESULTS: 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%).

CONCLUSIONS: 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.

Niacin decreases removal of high-density lipoprotein apolipoprotein A-I but not cholesterol ester by Hep G2 cells. Implication for reverse cholesterol transport.
Arterioscler Thromb Vasc Biol 1997 Oct;17(10):2020-8 (ISSN: 1079-5642) Jin FY; Kamanna VS; Kashyap ML
Cholesterol Center and Gerontology Section, Department of Veterans Affairs Medical Center, Long Beach, CA 90822, USA.

Niacin (nicotinic acid) is the most potent clinically used agent for increasing plasma HDL and apolipoprotein (apo) A-I. The mechanism by which niacin increases apoA-I is not clearly understood. We have examined the effect of niacin on the hepatic production and removal of apoA-I using Hep G2 cells as an in vitro model. Incubation of Hep G2 cells with niacin resulted in increased accumulation of apoA-I in the medium in a dose-dependent manner. Incorporation of [3H]leucine and [35S]methionine into apoA-I and apoA-I mRNA expression was unchanged by niacin, suggesting that it did not affect apoA-I de novo synthesis. Uptake of radiolabeled HDL protein and HDL apoA-I by Hep G2 cells was significantly reduced to as much as 82.9 +/- 2.2% (P = .04) and 84.2 +/- 2.8% (P = .02), respectively, of the baseline with increasing concentrations of niacin (0 to 3.0 mmol/L). Specific 125I-HDL protein uptake measured with a 50-fold excess of unlabeled HDL was reduced to as much as 78.3 +/- 4.8% (P = .005) in niacin-treated cells. The uptake of labeled cholesterol esters in HDL was unaffected by niacin.

Niacin also effected a similar decrease in HDL protein uptake, but not cholesterol esters, from apoA-I-containing HDL particles isolated by immunoaffinity. The conditioned medium obtained from Hep G2 cells incubated with niacin significantly (P = .002) increased cholesterol efflux from cultured human fibroblasts. These data indicate a novel mechanism whereby niacin selectively decreases hepatic removal of HDL apoA-I but not cholesterol esters, thereby increasing the capacity of retained apoA-I to augment reverse cholesterol transport.

Fifteen year mortality in Coronary Drug Project patients: long-term benefit with niacin.
J Am Coll Cardiol 1986 Dec;8(6):1245-55 (ISSN: 0735-1097)
Canner PL; Berge KG; Wenger NK; Stamler J; Friedman L; Prineas RJ; Friedewald W

The Coronary Drug Project was conducted between 1966 and 1975 to assess the long-term efficacy and safety of five lipid-influencing drugs in 8,341 men aged 30 to 64 years with electrocardiogram-documented previous myocardial infarction. The two estrogen regimens and dextrothyroxine were discontinued early because of adverse effects. No evidence of efficacy was found for the clofibrate treatment. Niacin treatment showed modest benefit in decreasing definite nonfatal recurrent myocardial infarction but did not decrease total mortality. With a mean follow-up of 15 years, nearly 9 years after termination of the trial, mortality from all causes in each of the drug groups, except for niacin, was similar to that in the placebo group. Mortality in the niacin group was 11% lower than in the placebo group (52.0 versus 58.2%; p = 0.0004). This late benefit of niacin, occurring after discontinuation of the drug, may be a result of a translation into a mortality benefit over subsequent years of the early favorable effect of niacin in decreasing nonfatal reinfarction or a result of the cholesterol-lowering effect of niacin, or both.

Coronary drug project: experience with niacin. Coronary Drug Project Research Group.
Eur J Clin Pharmacol 1991;40 Suppl 1:S49-51 (ISSN: 0031-6970)
Berge KG; Canner PL
Mayo Clinic, Rochester, Minnesota 55905.

Niacin was one of the treatments compared in the Coronary Drug Project, a placebo-controlled, multicenter trial of lipid-lowering drugs in the secondary prevention of coronary heart disease. A total of 1119 men, aged 30-64 at entry, were randomized to niacin and 2789 to placebo by the end of recruitment in March 1969. Although side-effects interfered with adherence to the niacin regimen, it was the most effective agent in achieving cholesterol-lowering (10% overall); other agents in the trial were clofibrate, dextrothyroxine, and conjugated equine estrogens. At the scheduled conclusion of the trial in February 1975, the niacin-treated group exhibited a statistically significantly lower incidence of definite, non-fatal myocardial infarction (MI) than the placebo group. There was a trend toward improvement in the life-table mortality curve, but this was not statistically significant. In 1981 an extended follow-up was carried out concerning vital status for the 6008 men who were still alive at the end of treatment and active follow-up in the trial in 1975 (827 in the niacin group and 2008 in placebo groups). Vital status was determined for 99.1% of these men after a mean of 9 years from conclusion of the trial. In the group previously randomized to niacin, there were 69 (11%) fewer deaths than were expected on the basis of mortality in the placebo group. This difference was significant (z = -3.52; P = 0.0004). The data also suggested that patients with a higher baseline cholesterol experienced greater benefit from niacin therapy, as did those with the best response to the drug.