Sildenafil and Exercise Capacity in the Elderly at Moderate Altitude

摘要: Objective Hypobaric hypoxia decreases exercise capacity and causes hypoxic pulmonary vasoconstriction hypertension. The phosphodiesterase-5 inhibitor sildenafil is a vasodilator that may improve at altitude. We aimed to determine whether improves capacity, measured as maximal oxygen consumption (peak Vo 2 ), moderate altitude in adults 60 years or older. Methods design was randomized, double-blind, placebo-controlled, crossover study. After baseline cardiopulmonary testing 1400 m, 12 healthy participants (4 women) aged older, who reside permanently approximately m are regularly active self-propelled mountain recreation above 2000 performed cycle tests hypobaric chamber simulated of 2750 after ingesting placebo. Results placebo, mean peak significantly lower than m: 37.0 mL · kg -1 min (95% CI, 32.7 41.3) vs 39.1 33.5 44.7; P = .020). there no difference heart rate (HR) workload either ( z 0.182; .668, respectively). There between placebo .668), O pulse .476), cardiac index .143), stroke volume 0.108), HR 0.919), .773). Transthoracic echocardiography immediately showed tricuspid annular plane systolic velocity higher .019), but excursion .720). Conclusions Sildenafil (50 mg) did not older our This might be explained by "dosing effect" insufficiently high