Avaliação da influência da presença de obesidade e da restrição de fluxo sanguíneo sobre as respostas cardiovasculares clínicas e ambulatoriais após uma sessão de caminhada em idosos hipertensos

Abstract

Introduction: Aerobic training with blood flow restriction (BFR) can offer important stimuli for improving muscle function, aerobic capacity, and cardiometabolic health, which is especially important for the elderly population. However, little is known about the acute effects of this type of physical exercise on the cardiovascular variables of individuals with hypertension, and whether the presence of obesity can influence these responses to aerobic exercise. Objective: To evaluate and compare clinical and ambulatory cardiovascular responses following a single session of walking, performed with and without BFR, in hypertensive older adults with and without obesity. Methods: Randomized clinical trial with 22 medicated hypertensive older adults, divided into two experimental groups: the Non-Obese Group (n=12; body mass index <30kg/m²) and the Obese Group (n=10; body mass index ≥30kg/m² and <35kg/m²). All individuals underwent preliminary procedures: medical history assessment; resting blood pressure (BP) measurement; anthropometric evaluation; and assessment of total BFR pressure. Subsequently, the subjects performed 2 experimental sessions in random order (Session Without BFR and Session With BFR), with a minimum interval of 72 hours between them. The experimental sessions consisted of the following periods: pre-intervention (with measurement of BP and heart rate - HR at seated rest); intervention period; and post-intervention period (with measurement of BP and HR for up to 55 minutes at seated rest, and measurements of BP and HR every 15 minutes for 24 hours under ambulatory conditions during daily life activities). During the intervention period of both experimental sessions, the subjects performed 30 minutes of walking at an intensity of 40-50% of heart rate reserve. Specifically in the Session With BFR, walking was performed with cuffs attached to both thighs and inflated to 40% of total BFR pressure. Results: The Obese Group presented significantly higher baseline anthropometric values and BP than the Non-Obese Group (p<0.05). In both experimental groups (Obese and Non-Obese), compared to pre-exercise values, there was a statistically significant reduction in systolic BP and mean BP, accompanied by a transient increase in HR at the post-exercise moment under clinical conditions, similarly between the With and Without BFR experimental sessions (p=0.001). The magnitude of the cardiovascular response under clinical conditions and the cardiovascular variables under ambulatory conditions were not influenced by the presence of obesity or the performance of BFR during walking (p>0.05). Conclusion: In hypertensive older adults, a single walking session can promote post-exercise hypotension under clinical conditions in systolic and mean BP, accompanied by a transient increase in HR. The presence of obesity and/or the performance of BFR during walking did not influence clinical and ambulatory cardiovascular responses.