Sex-specific differences in blood pressure responses following acute high-altitude exposure

Proper regulation of the systemic blood pressure is crucial for human health and may be affected in changing environmental conditions, e.g., during high-altitude exposure. Potential sex differences of such regulation are poorly understood. Here, we present data that indicate a blood pressure elevation only in men following acute high-altitude sojourn. Travelling to high altitude, i.e., >2500 m, increases systemic blood pressure (BP) at rest and during exercise in normotensive and hypertensive subjects.1 Although sex differences in BP regulation are well established,2 evidence on the interaction with acute high-altitude exposure is scarce. We previously reported resting BP data at high-altitude but sex-specific differences were not dissected.3 Here, we present and discuss resting and exercising BP data derived from our unique data set of two equally numbered and age-matched subsamples of both sexes (men: 39.1; 22–67 years and women: 39.9; 20–61 years). The full methods have been reported.3,4 In brief, healthy subjects were transported to high altitude by car and cable car. Resting measurements and submaximal exercise testing (stepping 60 times up and down a 24-cm step for 2 minutes) were performed at low altitude (600 m) and 2–5 h after arrival at high altitude (3480 m). Heart rate (HR) and peripheral oxygen saturation (SpO2) were determined by finger pulse oximetry (Onyx, NONIN) and systemic BP by the use of a wrist blood pressure monitor (OMRON R3). Acute mountain sickness (AMS) was assessed by the Lake Louise Score. Differences in physiologic responses to high altitude were evaluated separately for men and women using a paired t-test or Wilcoxon signed-rank test as appropriate. A P-value <0.05 was considered to indicate statistical significance. Participants provided written informed consent, and all studies were approved by the Ethical Commission of the Medical University of Innsbruck.