Effect of Niacin on Erectile Function in Men Suffering Erectile Dysfunction and Dyslipidemia

Abstract

Dyslipidemia is closely related to erectile dysfunction (ED). Evidence has shown that the lipid-lowering agent, 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitor (statins), can improve erectile function. However, information about the potential role of another class of lipid-lowering agent, niacin, is unknown. To assess the effect of niacin alone on erectile function in patients suffering from both ED and dyslipidemia. A single center prospective randomized placebo-controlled parallel-group trial was conducted. One hundred sixty male patients with ED and dyslipidemia were randomized in a one-to-one ratio to receive up to 1,500 mg oral niacin daily or placebo for 12 weeks. The primary outcome measure was the improvement in erectile function as assessed by question 3 and question 4 of the International Index of Erectile Function (IIEF Q3 and Q4). Secondary outcome measurements included the total IIEF score, IIEF-erectile function domain, and Sexual Health Inventory for Men (SHIM) score. From the overall analysis, the niacin group showed a significant increase in both IIEF-Q3 scores (0.53 ± 1.18, P < 0.001) and IIEF-Q4 scores (0.35 ± 1.17, P = 0.013) compared with baseline values. The placebo group also showed a significant increase in IIEF-Q3 scores (0.30 ± 1.16, P = 0.040) but not IIEF-Q4 scores (0.24 ± 1.13, P = 0.084). However, when patients were stratified according to the baseline severity of ED, the patients with moderate and severe ED who received niacin showed a significant improvement in IIEF-Q3 scores (0.56 ± 0.96 [P = 0.037] and 1.03 ± 1.20 [P < 0.001], respectively) and IIEF-Q4 scores (0.56 ± 1.03 [P = 0.048] and 0.84 ± 1.05 [P < 0.001], respectively] compared with baseline values, but not for the placebo group. The improvement in IIEF-EF domain score for severe and moderate ED patients in the niacin group were 5.28 ± 5.94 (P < 0.001) and 3.31 ± 4.54 (P = 0.014) and in the placebo group were 2.65 ± 5.63 (P < 0.041) and 2.74 ± 5.59 (P = 0.027), respectively. There was no significant improvement in erectile function for patients with mild and mild-to-moderate ED for both groups. For patients not receiving statins treatment, there was a significant improvement in IIEF-Q3 scores (0.47 ± 1.16 [P = 0.004]) for the niacin group, but not for the placebo group. Niacin alone can improve the erectile function in patients suffering from moderate to severe ED and dyslipidemia.