Upward shift and steepening of the blood pressure response to exercise in hypertensive subjects at high altitude

Background Acute exposure to high‐altitude hypobaric hypoxia induces a blood pressure rise in hypertensive humans, both at rest and during exercise. It is unclear whether this phenomenon reflects specific blood pressure hyperreactivity or rather an upward shift of blood pressure levels. We aimed at evaluating the extent and rate of blood pressure rise during exercise in hypertensive subjects acutely exposed to high altitude, and how these alterations can be counterbalanced by antihypertensive treatment. Methods and Results Fifty‐five subjects with mild hypertension, double‐blindly randomized to placebo or to a fixed‐dose combination of an angiotensin‐receptor blocker (telmisartan 80 mg) and a calcium‐channel blocker (nifedipine slow release 30 mg), performed a cardiopulmonary exercise test at sea level and after the first night's stay at 3260 m altitude. High‐altitude exposure caused both an 8 mm Hg upward shift (P<0.01) and a 0.4 mm Hg/mL/kg per minute steepening (P<0.05) of the systolic blood pressure/o...