All eyes on gas exchange: impact of controlled arterial hypertension on cardiopulmonary function and the effects of high-intensity interval training.

Abstract

Introduction: Arterial hypertension (AH) impairs vascular function which, in turn, may reduce cardiopulmonary function. However, the impact of AH on cardiorespiratory fitness (CRF) and its potential mechanisms remains insufficiently investigated. We compared cardiopulmonary function during exercise testing (CPET) between adults with and without AH (part 1) and evaluated the effects of high-intensity interval training (HIIT) in adults with AH on submaximal cardiopulmonary CPET parameters (part 2).

Methods: Thirty-eight adults with AH and 19 controls without AH partook in the study. Adults with AH were randomized into either HIIT or a control group. CPET assessed CRF and submaximal exercise parameters, including the oxygen uptake efficiency slope (OUES), V̇E/V̇CO 2 slope, PETCO 2 , V̇O 2 /work rate (WR) slope, and O 2 pulse. The HIIT intervention consisted of triweekly sessions over 8 weeks.

Results: Adults with AH had a 6.5 ml kg -1  min -1 (95% confidence interval: 1.7-11.3) lower CRF, a steeper V̇E/V̇CO 2 slope (moderate-large effect size), lower PETCO 2 (large effect size), flatter V̇O 2 /WR slope (moderate effect size), and lower O 2 pulse (small-moderate effect size) than adults without AH. HIIT improved CRF and altered certain cardio-circulatory parameters in AH, including OUES (small-large effect size), V̇O 2 /WR slope (small-moderate effect size, low precision) and O 2 pulse (small-moderate effect size). However, effects of HIIT on pulmonary-vascular parameters were inconclusive, with large variability observed in the V̇E/V̇CO 2 slope and PETCO 2 .

Conclusion: Adults with controlled AH might have lower CRF, indicating limitations in pulmonary-vascular and cardio-circulatory organ systems. A short-term 8-week HIIT enhances CRF and cardio-circulatory function, however, evidence is limited for improvements in pulmonary-vascular function.