Smoking and Risk of Erectile Dysfunction: Systematic Review of Observational Studies with Meta-Analysis

Background
There are many recent observational studies on smoking and risk of erectile dysfunction (ED) and whether smoking increases the risk of ED is still inconclusive. The objective of this meta-analysis was to synthesize evidence from studies that evaluated the association between smoking and the risk of ED.
Methods
We searched PubMed, Embase, Web of Science, and Scopus in January 2013 to identify cohort and case-control studies that evaluated the association between smoking and ED. Study quality of included studies was assessed by the Newcastle-Ottawa scale. Random-effects meta-analyses were used to combine the results of included studies.
Results
Four prospective cohort studies and four case-control studies involving 28, 586 participants were included. Because of significant heterogeneity after including case-control studies in meta-analysis, the consistent results of prospective cohort studies were considered more accurate, Because of significant heterogeneity after including case-control studies in meta-analysis, the consistent results of prospective cohort studies were considered more accurate, Compared with non-smokers, the overall odd ratio of ED in prospective cohort studies was 1.51(95% CI: 1.34 to 1.71) for current smokers, and it was 1.29 (95% CI: 1.07 to 1.47) for former smokers. Evidence of publication bias was not found.
Conclusion
Evidence from epidemiological studies suggests that smoking, especially current smoking, may significantly increase the risk of ED

背景 近年来已有多项关于吸烟与勃起功能障碍（erectile dysfunction, ED）发病风险相关性的观察性研究，但吸烟是否会升高ED发病风险尚无定论。本项荟萃分析旨在整合评估吸烟与ED风险关联的各类研究证据。
方法 本研究于2013年1月检索PubMed、Embase、Web of Science及Scopus数据库，筛选评估吸烟与ED关联的队列研究及病例对照研究。采用纽卡斯尔-渥太华量表（Newcastle-Ottawa scale）对纳入研究的质量进行评价，并通过随机效应模型荟萃分析整合纳入研究的结果。
结果 本研究共纳入4项前瞻性队列研究与4项病例对照研究，涉及28586名研究对象。由于纳入病例对照研究后荟萃分析存在显著异质性，因此前瞻性队列研究的一致性结果被认为更为可靠。与非吸烟者相比，当前吸烟者发生ED的综合优势比为1.51（95%置信区间：1.34~1.71），既往吸烟者的综合优势比为1.29（95%置信区间：1.07~1.47）。未发现存在发表偏倚的证据。
结论 流行病学研究证据表明，吸烟（尤其是当前吸烟行为）可能显著升高ED的发病风险。