UPWARD-SHIFT AND STEEPENING OF THE BLOOD PRESSURE RESPONSE TO EXERCISE IN HYPERTENSIVE SUBJECTS AT HIGH ALTITUDE. (June 2018)

• Record Type: Journal Article
• Authors: Baratto, C.; Caravita, S.; Faini, A.; Bilo, G.; Macarlupu, J.; Lang, M.; Revera, M.; Lombardi, C.; Villafuerte, F.; Agostoni, P.; Parati, G.
• Is Part Of: Journal of hypertension. Volume 36(2018)Supplement 1
• Publication Date: 2018-06
• Subjects: Hypertension -- Periodicals; Hypertension -- Periodicals; 616.132005
• DOI: 10.1097/01.hjh.0000539454.51256.96
• Languages: English
• ISSNs: 1473-5598

Abstract

Abstract : Objective: 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. Design and method: Fifty-five mild hypertensive subjects, 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 of stay at 3260 m altitude. Results: High altitude exposure caused both a 8 mmHg upward-shift (p < 0.01) and a 0.4 mmHg/mL/Kg/min steepening (p < 0.05) of the systolic blood pressure/oxygen consumption relationship during exercise, independently of treatment (figure 1a). Telmisartan/nifedipine did not modify blood pressure reactivity to exercise, but downward shifted (p < 0.001) the relationship between systolic blood pressure and oxygen consumption by 26 mmHg, both at sea level and at altitude (figure 1a). Muscle oxygen delivery, as evaluated by means of the relationship between oxygen consumption and workload, was not influenced by altitude exposure, but was higher on telmisartan/nifedipine than on placebo (p < 0.01, figure 1b). Figure. No caption available. Conclusions: In hypertensive subjects exposed to high altitude we observed a hypoxia-driven upward-shift and steepening of the blood pressure response to exercise. The effect of the combination of telmisartan/nifedipine slow-release outweighed these changes, and was associated with better muscle oxygen delivery.