Efficacy of Sildenafil on healthy humans in high-altitude hypoxia at rest and during exercise: A meta-analysis

The current meta-analysis aimed to fully evaluate the efficacy of Sildenafil in healthy humans at different altitudes, focusing on echocardiographic and hemodynamic parameters. Relevant studies were retrieved from the Cochrane, Embase and PubMed databases. Odds ratios (OR) were determined for dichotomous data and weighted mean differences with 95% confidence intervals (CIs) for continuous data. A total of 16 RCTs were included in the current meta-analysis. Short-term treatment with Sildenafil significantly elevated resting heart rate (P<0.01) at altitudes <4,000 meters. No significant differences in heart rate were observed between the Sildenafil and placebo groups at rest and during exercise at an altitude of >4,000 meters (P>0.05). Sildenafil improved resting cardiac output at an altitude of >5,000 meters (P<0.01) and exercising arterial oxygen saturation at <4,000 meters (P<0.01). Sildenafil reduced resting pulmonary artery systolic pressure (PASP) at altitudes >4,000 meters (P<0.01) and exercising PASP at altitudes >5,000 meters (P<0.01). Therefore, Sildenafil efficacy in healthy humans with high-altitude hypoxia is related to altitude and rest or exercise.