This randomized, double-blind, placebo-controlled study was designed to explore the effects of exposure to very high altitude hypoxia on vascular wall properties and to clarify the role of renin-angiotensin-aldosterone system inhibition on these vascular changes. Forty-seven healthy subjects were included in this study: 22 randomized to telmisartan (age, 40.3Â±10.8 years; 7 women) and 25 to placebo (age, 39.3Â±9.8 years; 7 women). Tests were performed at sea level, pre- and post-treatment, during acute exposure to 3400 and 5400-m altitude (Mt. Everest Base Camp), and after 2 weeks, at 5400 m. The effects of hypobaric hypoxia on mechanical properties of large arteries were assessed by applanation tonometry, measuring carotid-femoral pulse wave velocity, analyzing arterial pulse waveforms, and evaluating subendocardial oxygen supply/demand index. No differences in hemodynamic changes during acute and prolonged exposure to 5400-m altitude were found between telmisartan and placebo groups. Aortic pulse wave velocity significantly increased with altitude (P<0.001) from 7.41Â±1.25 m/s at sea level to 7.70Â±1.13 m/s at 3400 m and to 8.52Â±1.59 m/s at arrival at 5400 m (P<0.0001), remaining elevated during prolonged exposure to this altitude (8.41Â±1.12 m/s; P<0.0001). Subendocardial oxygen supply/demand index significantly decreased with acute exposure to 3400 m: from 1.72Â±0.30 m/s at sea level to 1.41Â±0.27 m/s at 3400 m (P<0.001), remaining significantly although slightly less reduced after reaching 5400 m (1.52Â±0.33) and after prolonged exposure to this altitude (1.53Â±0.25; P<0.001). In conclusion, the acute exposure to hypobaric hypoxia induces aortic stiffening and reduction in subendocardial oxygen supply/demand index. Renin-angiotensin-aldosterone system does not seem to play any significant role in these hemodynamic changes. Clinical Trial Registration - URL: https://www.clinicaltrialsregister.eu/. Unique identifier: 2008-000540-14.
Renin-Angiotensin-Aldosterone System Is Not Involved in the Arterial Stiffening Induced by Acute and Prolonged Exposure to High Altitude / M. Revera, P. Salvi, A. Faini, A. Giuliano, F. Gregorini, G. Bilo, C. Lombardi, G. Mancia, P. Agostoni, G. Parati. - In: HYPERTENSION. - ISSN 0194-911X. - 70:1(2017 Jul), pp. 75-84.
|Titolo:||Renin-Angiotensin-Aldosterone System Is Not Involved in the Arterial Stiffening Induced by Acute and Prolonged Exposure to High Altitude|
SALVI, PAOLO (Secondo)
AGOSTONI, PIERGIUSEPPE (Penultimo)
|Parole Chiave:||altitude; altitude sickness; hemodynamics; pulse wave analysis; pulse wave velocity; renin-angiotensin system; vascular stiffness; adult; angiotensin II Type 1 receptor blockers; biological availability; biological oxygen demand analysis; female; hemodynamics; humans; male; manometry; middle aged; pulse wave analysis; treatment outcome; altitude sickness; aorta; benzimidazoles; benzoates; renin-angiotensin system; vascular stiffness; internal medicine|
|Settore Scientifico Disciplinare:||Settore MED/11 - Malattie dell'Apparato Cardiovascolare|
|Data di pubblicazione:||lug-2017|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1161/HYPERTENSIONAHA.117.09197|
|Appare nelle tipologie:||01 - Articolo su periodico|