Efeitos agudos do exercício resistido sobre as respostas cardiovasculares de pessoas vivendo com HIV/AIDS

Abstract

Introduction: It remains unclear whether a session of resistance exercise (RE) induces post-exercise hypotension (PEH) in people living with HIV (PLHIV). Objective: To compare cardiovascular responses to an RE session in PLHIV versus uninfected controls. Methods: Nine PLHIV (HIV+; 47.2±9.5 years) and nine healthy controls (HIV-; 44.4±10.2 years) completed, in randomized order, a control session (no exercise) and an RE session (6 exercises; 3 sets of 12 maximum repetitions). Cardiovascular and cardiac autonomic modulation responses were assessed before and up to 60 minutes after the experimental sessions using digital photoplethysmography and heart rate variability, respectively. Results: At rest, the groups showed similar results for systolic/diastolic blood pressure [SBP/DBP] (HIV-: 120.8±12.5/75.8±6.5 vs. HIV+: 126.7±18.5/75.7±9.8 mmHg; p=0.4), heart rate [HR] (HIV-: 60.9±10.8 vs. HIV+: 66.4±8.2 bpm; p=0.2), stroke volume [SV] (HIV-: 85.2±17.7 vs. HIV+: 100.0±24.4 mL; p=0.1), and peripheral vascular resistance [PVR] (HIV-: 1.17±0.30 vs. HIV+: 0.92±0.22 mmHg.s/mL; p=0.07), except for cardiac output [CO], which was higher in the HIV+ group vs. HIV- (6.5±0.9 vs. 5.2±1.1 L/min; p=0.02). Heart rate variability indices were also similar between groups at rest (SDNN and rMSSD p=0.26; pNN50 p=0.12). Net effect analysis [(post-pre-exercise session) - (post-pre-control session)] showed that the HIV+ group had a greater reduction in SBP (-6.5±7.0 vs. -2.8±9.4 mmHg; p=0.01), in DBP (-14.5±2.3 vs. -3.7±4.4 mmHg; p=0.001), and a larger increase in CO (1.34±0.16 vs. 0.80±0.16 L/min; p=0.02) in post-exercise recovery. Additionally, the HIV+ group showed less reduction post-exercise in HR (20.37±10.62 vs. 12.15±12.61 bpm, p=0.001), SDNN (-22.43±5.46 vs. -10.23±6.94 ms, p=0.001), rMSSD (-24.19±5.51 vs. -11.58±7.99 ms, p=0.0001), and pNN50 (-15.78±2.76 vs. -7.98±2.40 %, p=0.01) compared to the HIV- group. Within-group reductions (exercise session vs. control) occurred in the HIV- group for DBP (~7 mmHg, from 15 to 60 min; p<0.05) and PVR (~0.38 mmHg.s/mL, from 30 to 45 min; p<0.05), associated with an increase in CO (~1.0 L/min, from 15 to 60 min; p<0.05). In the HIV+ group, only DBP reduction (~8 mmHg, from 15 to 60 min) was observed in the exercise session vs. control (p<0.05). HR was elevated in the exercise session compared to the control in both groups at all evaluated times (p<0.001). The HIV+ group presented lower SDNN and rMSSD in the exercise session compared to the control at all evaluated times (p=0.01). In the HIV- group, no differences were detected for SDNN, and rMSSD was lower in the exercise session vs. control only at 0 (15.09±12.34 vs. 42.23±28.63 ms; P<0.0001) and 60 minutes (23.05±8.79 vs. 42.11±22.98 ms; P=0.01). Both groups showed lower pNN50 in the exercise session compared to control at all evaluated times (P=0.02 for HIV- and P=0.04 for HIV+). Conclusion: An RE session induces more pronounced PEH in PLHIV, which is not associated with autonomic modulation. The mechanisms underlying this response remain unclear