BACKGROUND: Obstructive sleep apnoea syndrome (OSAS) is associated with several chronic diseases, including erectile dysfunction (ED). The association of OSAS and ED is far more common than might be found by chance; the treatment of OSAS with non-invasive positive airway pressure therapy is associated with improvement of respiratory symptoms, and may contribute to the improvement of associated conditions, such as ED.
OBJECTIVES: To assess the effectiveness and acceptability of non-invasive positive airway pressure therapy for improving erectile dysfunction in OSAS.
SEARCH METHODS: We identified studies from the Cochrane Airways Trials Register, CENTRAL, MEDLINE, Embase, PsycINFO, CINAHL, AMED EBSCO, and LILACS, the US National Institutes of Health ongoing trials register ClinicalTrials.gov, and the World Health Organisation international clinical trials registry platform to 14 June 2021, with no restriction on date, language, or status of publication. We checked the reference lists of all primary studies, and review articles for additional references, and relevant manufacturers' websites for study information. We also searched specific conference proceedings for the British Association of Urological Surgeons; the European Association of Urology; and the American Urological Association to 14 June 2021.
SELECTION CRITERIA: We considered randomised controlled trials (RCTs) with a parallel or cross-over design, or cluster-RCTs, which included men aged 18 years or older, with OSAS and ED. We considered RCTs comparing any non-invasive positive airway pressure therapy (such as continuous positive airways pressure (CPAP), bilevel positive airway pressure (BiPAP), variable positive airway pressure (VPAP), or similar devices) versus sham, no treatment, waiting list, or pharmacological treatment for ED. The primary outcomes were remission of ED and serious adverse events; secondary outcome were sex-related quality of life, health-related quality of life, and minor adverse events.
DATA COLLECTION AND ANALYSIS: Two review authors independently conducted study selection, data extraction, and risk of bias assessment. A third review author solved any disagreement. We used the Cochrane RoB 1 tool to assess the risk of bias of the included RCTs. We used the GRADE approach to assess the certainty of the body of evidence. To measure the treatment effect on dichotomous outcomes, we used the risk ratio (RR); for continuous outcomes, we used the mean difference (MD). We calculated 95% confidence intervals (CI) for these measures. When possible (data availability and homogeneous studies), we used a random-effect model to pool data with a meta-analysis.
MAIN RESULTS: We included six RCTs (all assessing CPAP as the non-invasive positive airway pressure therapy device), with a total of 315 men with OSAS and ED. All RCTs presented some important risk of bias related to selection, performance, assessment, or reporting bias. None of included RCTs assessed the ED remission rate, and we used the provided ED mean scores as a proxy. CPAP versus no CPAP There is uncertainty about the effect of CPAP on mean ED scores after 4 weeks, using the International index of erectile function (IIEF-5, higher = better; MD 7.50, 95% CI 4.05 to 10.95; 1 RCT; 27 participants; very low-certainty evidence), and after 12 weeks (IIEF-ED, ED domain; MD 2.50, 95% CI -1.10 to 6.10; 1 RCT; 57 participants; very low-certainty evidence, downgraded due to methodological limitations and imprecision). There is uncertainty about the effect of CPAP on sex-related quality of life after 12 weeks, using the Self-esteem and relationship test (SEAR, higher = better; MD 1.00, 95% CI -8.09 to 10.09; 1 RCT; 57 participants; very low-certainty evidence, downgraded due to methodological limitations and imprecision); no serious adverse events were reported after 4 weeks (1 RCT; 27 participants; very low-certainty evidence, downgraded due to methodological limitations and imprecision). CPAP versus sham CPAP One RCT assessed this comparison (61 participants), but we were unable to extract outcomes for this comparison due to the factorial design and reporting of this trial. CPAP versus sildenafil (phosphodiesterase type 5 inhibitors) Sildenafil may slightly improve erectile function at 12 weeks when compared to CPAP, measured with the IIEF-ED (MD -4.78, 95% CI -6.98 to -2.58; 3 RCTs; 152 participants; I² = 59%; low-certainty evidence, downgraded due to methodological limitations). There is uncertainty about the effect of CPAP on sex-related quality of life after 12 weeks, measured with the Erectile Dysfunction Inventory of Treatment Satisfaction questionnaire (EDITS, higher = better; MD -1.24, 95% CI -1.80 to -0.67; 2 RCTs; 122 participants; I² = 0%; very low-certainty evidence, downgraded due to methodological limitations). No serious adverse events were reported for either group (2 RCTs; 70 participants; very low-certainty evidence, downgraded due to methodological limitations and imprecision). There is uncertainty about the effects of CPAP when compared to sildenafil for the incidence of minor adverse events (RR 1.33, 95% CI 0.34 to 5.21; 1 RCT; 40 participants; very low-certainty evidence, downgraded due to methodological limitations and imprecision). The confidence interval was wide and neither a significant increase nor reduction in the risk of minor adverse events can be ruled out with the use of CPAP (4/20 men complained of nasal dryness in the CPAP group, and 3/20 men complained of transient flushing and mild headache in the sildenafil group).
AUTHORS' CONCLUSIONS: When compared with no CPAP, we are uncertain about the effectiveness and acceptability of CPAP for improving erectile dysfunction in men with obstructive sleep apnoea. When compared with sildenafil, there is some evidence that sildenafil may slightly improve erectile function at 12 weeks.
