Supplementary Material for: The relationship between erectile dysfunction and obstructive sleep apnoea and the impact on severity of ED following treatment of OSA: A systematic review

Background:
Erectile dysfunction is a debilitating condition defined as the inability to achieve or maintain penile erection sufficient for satisfactory sexual activity. Obstructive sleep apnoea is a common sleep disorder resulting in episodes of intermittent hypoxia experienced by the patient. It has been hypothesized that a link between both conditions exists.

Aim:
This systematic review aims to evaluate the current literature and synthesise the evidence linking erectile dysfunction and obstructive sleep apnoea, the possible pathogenesis involved and potential treatment options available.

Design:
A mixed method systematic review and narrative synthesis reporting qualitative and quantitative data.

Data sources:
The databases Medline, PubMed and EMBASE were searched between January 2000 and January 2022.

Results:
Eighteen studies were included, comprising 5 randomised controlled trials, 11 prospective studies and 2 cross-sectional study. The literature has reported up to 82% prevalence of ED in patients with OSA. Studies investigating the role of CPAP in treating ED in this cohort of patients has shown results varying from no significant effect to complete resolution of ED.

Conclusion:
There does appear to be an association between the presence of OSA and ED. Further randomised controlled trials to evaluate the efficacy of CPAP on ED in patients with OSA need to be conducted. Until more robust evidence is available, CPAP is a safe treatment likely to improve symptoms in individuals with OSA. However, the degree to which it may affect ED symptoms is not yet clear, but what appears clear is that it does not negatively impact on erectile function and is most likely to offer some degree of improvement.

背景：
勃起功能障碍（Erectile dysfunction）是一种使人衰弱的病症，定义为无法获得或维持足以完成满意性生活的阴茎勃起。阻塞性睡眠呼吸暂停（Obstructive sleep apnoea）是一种常见睡眠障碍，会导致患者出现间歇性缺氧发作。已有假说认为二者之间存在关联。

研究目的：
本系统综述旨在评估现有文献，综合勃起功能障碍与阻塞性睡眠呼吸暂停之间关联的相关证据、涉及的潜在发病机制以及可用的潜在治疗方案。

研究设计：
采用混合方法系统综述与叙事性综合研究，同时报告定性与定量数据。

数据来源：
于2000年1月至2022年1月期间，检索Medline、PubMed及EMBASE数据库。

研究结果：
共纳入18项研究，其中包括5项随机对照试验（randomised controlled trials）、11项前瞻性研究（prospective studies）以及2项横断面研究（cross-sectional study）。文献报道显示阻塞性睡眠呼吸暂停患者中勃起功能障碍的患病率高达82%。针对持续气道正压通气（CPAP，Continuous Positive Airway Pressure）在该类患者中治疗勃起功能障碍的作用的研究结果显示，疗效从无显著改善到勃起功能障碍完全缓解不等。

结论：
现有证据表明阻塞性睡眠呼吸暂停与勃起功能障碍之间确实存在关联。未来仍需开展更多随机对照试验，以评估持续气道正压通气对阻塞性睡眠呼吸暂停患者勃起功能障碍的疗效。在获得更确凿的证据之前，持续气道正压通气是一种安全的治疗手段，有望改善阻塞性睡眠呼吸暂停患者的相关症状。不过，其对勃起功能障碍症状的改善程度尚不明确，但可以明确的是，该治疗不会对勃起功能产生负面影响，且大概率可在一定程度上改善症状。