Sildenafil versus continuous positive airway pressure for erectile dysfunction in men with obstructive sleep apnea: a meta-analysis

Objective.?To evaluate the effectiveness of sildenafil versus continuous positive airway pressure (CPAP) for patients with erectile dysfunction (ED) and obstructive sleep apnea (OSA).

Methods.?This is a meta-analysis of a randomized controlled trial. The main outcome measures for effectiveness were the percentage of successful intercourse attempts, International Index of Erectile Function (IIEF) domain scores (erectile function, EF) and the satisfaction levels of the patients and their partners with the treatment for ED.

Results.?Two randomized controlled trials totaling 70 patients were included. Meta-analysis results are as follows: after 12 weeks of treatment, patients under sildenafil demonstrated a significant advantage over under CPAP in terms of the percentage of successful intercourse attempts [OR?=?3.24, 95% CI (2.37–4.43)], EF scores [WMD?=?3.57, 95%CI (1.68–5.45)], and the satisfaction levels of the patients and their partners with the treatment for ED [OR?=?3.56, 95% CI (1.27–9.98)].

Conclusion.?Current clinical studies might confirm that both therapeutic methods were safe and effective, but sildenafil was superior to CPAP in the treatment of ED in men with OSA. We conclude that new therapeutic agents or a combination of the two methods should be studied further.     

Testosterone therapy in erectile dysfunction

Studies in animals have indicated that the nitric oxide erectile pathway is testosterone-dependent. Castration induces erectile dysfunction and a reduction in nitric oxide synthase-stained nerves in erectile tissue. Furthermore, castration adversely affects penile hemodynamics and smooth muscle content, leading to veno-occlusive dysfunction. Testosterone replenishment reverses these physiological, biochemical and structural changes. Several clinical studies have demonstrated the benefits of a combination of testosterone and sildenafil. A recently published, multicenter study evaluated the safety and efficacy of testosterone gel 1% (Testogel®; Schering AG, Germany/AndroGel®; Solvay Pharmaceuticals) vs. placebo gel in conjunction with sildenafil, in producing an erectile response in hypogonadal men who did not respond to treatment with sildenafil alone for erectile dysfunction. The selection criteria required subjects to have had erectile dysfunction for at least 3 months, to be non-responsive to 100 mg sildenafil and to have low testosterone levels (<?400 ng/dl). The primary efficacy measurement was the mean change from baseline in the Erectile Function domain of the International Index of Erectile Function (IIEF). Secondary outcome measures included the mean change from baseline in the other domains and the total sum of the IIEF. Subjects were randomized to receive either testosterone gel + sildenafil, or placebo gel + sildenafil for 12 weeks. Testosterone therapy with testosterone gel improved the erectile response to sildenafil. Therefore, testosterone therapy may be considered for the treatment of erectile dysfunction in men with low to low-normal testosterone levels, who have failed prior treatment with sildenafil alone. Consequently, it is important to screen for hypogonadism in men who fail PDE5 inhibitors.