スタチンは勃起不全の症状を改善する（Abstract 14-A-7744）

スタチンは勃起不全を有する高コレステロールの男性にさらなる有益性を提供する可能性がある

Statins may offer additional benefit for men with high cholesterol and erectile dysfunction

スタチンは勃起不全を有意に改善させるとの研究者らが期待する事実により、心臓発作のリスク軽減目的でスタチン内服を必要とする男性らが勇気付けられるだろうとの研究結果が第63回American College of Cardiology学会で発表され、同時にJournal of Sexual Medicineオンライン版に掲載された。勃起不全とスタチンに関する過去のスタディの初めてのメタ解析において、研究者らはInternational Inventory of Erectile Function－5つの質問を用いた自己評価で、それぞれの質問につき5点満点で合計し、点数が低いほど性機能低下を示す－を用いて、勃起機能を計測した。11のスタディ全てを組み合わせた解析の結果、勃起不全を有する高コレステロールの男性において、スタチンの勃起機能に対する統計学的に有意な効果が示された。全体で、勃起機能スコアはスタチン内服男性で3.4%高かった（14.0から17.4へ上昇、23.4%上昇）。スタチンによる勃起機能スコア上昇は、シルデナフィルやタダラフィルのような薬剤で報告されているスコア上昇のほぼ3分の1から2分の1であった。スタチンは血管の適切な拡張およびペニスへの血流改善を促すことにより勃起機能を改善するのであろうと研究者らは考えている。

Statins are associated with a significant improvement in erectile function, a fact researchers hope will encourage men who need statins to reduce their risk of heart attack to take them, according to research presented at the American College of Cardiology's 63rd Annual Scientific Session and simultaneously published online in the Journal of Sexual Medicine.

Erectile dysfunction is common in older men, especially among those with cardiovascular risk factors where cholesterol-lowering statins are frequently prescribed. Previous research has suggested a negative association between statin therapy and testosterone levels, leading to questions about the effects of these widely used medications on the quality of erection.

In the first meta-analysis of previous studies on erectile dysfunction and statins, researchers identified 11 randomized, controlled trials that measured erectile function using the International Inventory of Erectile Function – a self-administered survey with five questions, each scored on a five-point scale and totaled, with lower values representing poorer sexual function. Analysis of all 11 studies combined found a statistically significant effect of statins on erectile function in men who had both high cholesterol and erectile dysfunction. Overall, erectile function scores increased by 3.4 points in men who took statins (from 14.0 to 17.4, a 24.3 percent increase).

"The increase in erectile function scores with statins was approximately one-third to one-half of what has been reported with drugs like sildenafil or tadalafil," said John B. Kostis, M.D., director of the Cardiovascular Institute and associate dean for Cardiovascular Research at Rutgers Robert Wood Johnson Medical School, and the lead investigator of the study.

"It was larger than the reported effect of lifestyle modification," Kostis said. "For men with erectile dysfunction who need statins to control cholesterol, this may be an extra benefit."

Researchers believe that statins may work to improve erectile function by helping blood vessels dilate properly and improving vascular blood flow to the penis, which is often restricted in men with erectile dysfunction. While statins are not recommended as a primary treatment for erectile dysfunction in patients with healthy cholesterol levels, the added benefit may encourage more men who need statins to take them. Millions of people are prescribed statins to prevent heart disease, but some stop taking the medication or take less than the prescribed dose, Kostis said. Rather than preventing the possibility of a heart attack in the future, the more immediate benefit of improving erectile function might improve adherence to statin therapy, he added.

Erectile dysfunction affects an estimated 18 million to 30 million men and occurs more often in men over the age of 40. Common causes include heart disease, high cholesterol, high blood pressure, diabetes, obesity, tobacco use, depression and stress.

Kostis said that larger randomized controlled trials are needed to further investigate the link between statin therapy and erectile function.