Efeitos do exercício isométrico de preensão manual nas respostas cardiovasculares de idosos: uma revisão sistemática e um ensaio clínico randomizado

Abstract

Introduction: Hypertension (HTN) is a multifactorial condition characterized by the persistent elevation of blood pressure (BP), being one of the main risk factors for cardiovascular diseases. Studies indicate that isometric handgrip exercise (IHG) may contribute to reducing blood pressure, but there is a gap in the literature regarding its effects on hypertensive elderly women. Objective: This study analyzed the acute effects of IHG on BP responses and cardiac autonomic modulation (CAM) in hypertensive elderly women. Methods: The study included 12 trained hypertensive elderly women with controlled BP, with a mean age of 67.8 ± 3.8 years. A randomized, crossover clinical trial was conducted. Participants performed IHG at 30% and the control session (C) at 3% of the maximal voluntary isometric contraction (MVIC) using a stress ball, in four sets of one-minute contractions for each hand, interspersed with one-minute rest periods. A minimum interval of 72 hours between sessions was maintained. BP and heart rate variability (HRV) were monitored at baseline and at 15, 30, 45, and 60 minutes post-IHG and post-C. Results: The analysis revealed a significant effect of the time factor on systolic (SBP), diastolic (DBP) and mean (MAP) blood pressure (P < 0.01). Furthermore, the time vs intervention interaction was significant for SBP (p = 0.04), with pairwise comparisons showing that SBP in the IHG group at 30 (p = 0.04), 45 (p = 0.04) and 60 (p = 0.01) minutes post-intervention was higher when compared to the pre moment. Regarding HRV, it was observed that the mean HR reduced after 45 and 60 min (p < 0.01) when compared to the pre-intervention moment when IHG and C were performed, which was accompanied by an increase in SDNN (p < 0.05) and SD2 (p < 0.05). Intervention C also showed an increase in the short-term vagal modulation variables RMSSD (p<0.01) and SD1 (p<0.01) at the time post 45 min when compared to pre. No difference was reported between the interventions for the HRV variables (P > 0,05). Conclusion: According to the results reported, IHG performed with a stress ball increased BP in trained hypertensive elderly women with controlled BP for up to 60 minutes. Moreover, it was observed that the performed IHG did not affect the CAM of participants.