RESUMO
Reduced cardiac baroreflex sensitivity (cBRS) is an autonomic marker associated with a worse cardiovascular prognosis. Whether cBRS is lowered in people living with HIV (PLHIV) is yet unclear, as well as potential moderator effects of body mass index (BMI) or physical activity (PA) level. The present study aims to compare the spontaneous cBRS in PLHIV vs. HIV-uninfected controls, and to determine among PLHIV the relationship between cBRS vs. body mass index (BMI) and PA level. Total, upward (cBRS+), and downward (cBRS-) cBRS gains were assessed using the sequential method from beat-to-beat blood pressure at rest in 16 PLHIV (46.5±8.4 years) under antiretroviral therapy for at least 6 months, and 16 HIV-uninfected controls (CTL; 42.1±8.0 years). PA level was assessed by the Physical Activity Questionnaire (IPAQ short version) overall score. PLHIV showed lower total cBRS (8.7±3.1 vs. 15.3±7.7 ms.mmHg-1; p < 0.01), cBRS+ (9.2±4.9 vs. 16.0±6.8 ms.mmHg-1; p < 0.01) and cBRS- (9.5±4.9 vs. 15.3±9.3 ms.mmHg-1; p < 0.01) vs. CTL. No between-group difference was found for BMI (PLHIV: 25.2±2.6 vs. CTL: 26.8±3.2 kg.m-2; p > 0.05) or IPAQ score (PLHIV: 2.4±1.0 vs. CTL: 2.0±1.4; p > 0.05). In PLHIV, total cBRS was inversely correlated vs. BMI (r = -0.44; p = 0.04), but not vs. IPAQ score (r = 0.17; p = 0.26). HIV infection may reduce spontaneous cBRS, which seemed to be moderated by higher BMI, but not PA level of PLHIV.
RESUMO
PURPOSE: This study aims to investigate the effects of acute cycling on blood pressure (BP), arterial function, and heart rate variability (HRV) in men living with HIV (MLHIV) using combined antiretroviral therapy (cART). METHODS: Twelve MLHIV (48.7 ± 9.2 years; 25.2 ± 2.8 kg m-2) and 13 healthy controls (41.2 ± 9.9 years; 26.3 ± 2.9 kg m-2) performed a cycling bout (ES) (intensity: 50% oxygen uptake reserve; duration: time to achieve 150 kcal-MLHIV: 24.1 ± 5.5 vs. controls: 23.1 ± 3.0 min; p = 0.45), and a 20-min non-exercise session (NES). RESULTS: At rest (p < 0.05), MLHIV presented higher brachial systolic/diastolic BP (SBP/DBP: 123.2 ± 14.2/76.8 ± 6.3 vs. 114.3 ± 5.1/71.6 ± 2.6 mmHg) and central BP (cSBP/cDBP: 108.3 ± 9.3/76.5 ± 6.5 vs. 101.6 ± 4.9/71.3 ± 4.4 mmHg) vs. controls but lower absolute maximal oxygen uptake (2.1 ± 0.5 vs. 2.5 ± 0.3 L min-1) and HRV indices reflecting overall/vagal modulation (SDNN: 24.8 ± 7.1 vs. 42.9 ± 21.3 ms; rMSSD: 20.5 ± 8.5 vs. 38.1 ± 22.8 ms; pNN50: 3.6 ± 4.2 vs. 13.6 ± 11.3%). DBP postexercise lowered in controls vs. MLHIV (â¼4 mmHg, p < 0.001; ES: 0.6). Moreover, controls vs. MLHIV had greater reductions (p < 0.05) in augmentation index (-13.6 ± 13.7 vs. -3.1 ± 7.2% min-1; ES: 2.4), and HRV indices up to 5 min (rMSSD: -111.8 ± 32.1 vs. -75.9 ± 22.2 ms min-1; ES: 3.8; pNN50: -76.3 ± 28.3 vs. -19.0 ± 13.7% min-1; ES: 4.4). Within-group (ES vs. NES; p < 0.05) reductions occurred in controls for SBP (â¼10 mmHg, 2 h), DBP (â¼6 mmHg, 20, 30, and 70 min), cSBP (â¼9 mmHg, 30 min), cDBP (â¼7 mmHg, 30 and 70 min), augmentation index (â¼10%, 30 min), and pNN50 (â¼20%; up to 2 h), while in MLHIV only cSBP (â¼6 mmHg, 70 min) and cDBP (â¼4 mmHg, 30 min) decreased. Similar increases (up to 5 min) in heart rate (â¼22 bpm) and decreases in SDNN (â¼18 ms) and rMSSD (â¼20 ms) occurred in both groups. CONCLUSION: MLHIV under cART exhibited attenuated postexercise hypotension vs. healthy controls, which seemed to relate with impairments in vascular function.