Efeitos da ingestão de água na função autonômica cardíaca e do treinamento físico em variáveis funcionais, antropométricas e de qualidade de vida em pacientes com cirrose hepática

Abstract

Background: Liver cirrhosis is the final stage of several chronic liver diseases, characterized by extensive fibrosis and nodular remodeling, leading to systemic complications such as autonomic dysfunction, muscle mass loss, and reduced functional capacity. Although studies in healthy individuals have shown that water intake can modulate the autonomic nervous system, its effects in patients with liver cirrhosis—particularly in the presence of clinically significant portal hypertension (CSPH) remain poorly explored. Furthermore, the impact of aerobic and resistance training on functional, anthropometric, and quality-of-life variables still shows contradictory results in these patients. Purpose: The objective of Study 1 was to evaluate the effect of water intake on the cardiac vagal index and heart rate in patients with cirrhosis, considering the presence of CSPH. Study 2 aimed to analyze, through a systematic review, the effects of aerobic and resistance training on quality of life, functional capacity, and body composition in patients with cirrhosis. Methods: In Study 1, 37 patients with cirrhosis (Child–Pugh A or B) performed a four-second exercise test to measure the cardiac vagal index at baseline and at 10, 20, and 30 minutes after ingesting 500 ml of water; heart rate was recorded at the same time points. CSPH was defined according to the Baveno VII criteria. In Study 2, a systematic review was conducted in MEDLINE, Cochrane Library, and Web of Science, including controlled and randomized clinical trials that compared aerobic or resistance exercise versus no-intervention control in patients with liver cirrhosis. The following outcomes were analyzed: quality of life, peak oxygen consumption (VO₂peak), body mass index (BMI), distance covered in the 6-minute walk test (6MWT), and thigh circumference. The quality of evidence was assessed using the GRADE system. Results: In Study 1, water intake significantly increased the cardiac vagal index at 10, 20, and 30 minutes (p=0.021; p=0.022; p=0.037) and reduced heart rate (p=0.021; p<0.001; p<0.001), with no relevant difference between patients with or without CSPH. In Study 2, six clinical trials (n=244; 53–63 years; Child–Pugh A–C) were included. Resistance training improved quality of life (standardized mean difference = 0.36; p=0.04), and combined aerobic and resistance training increased the 6MWT distance (+49.39 m; p=0.03), with no significant effects on VO₂peak, BMI, or thigh circumference. The quality of evidence ranged from very low to moderate. Conclusion: Water intake promoted an increase in cardiac vagal activity and a reduction in heart rate in patients with cirrhosis, regardless of the presence of CSPH. Aerobic and resistance training proved effective in improving functional capacity and quality of life, without changes in body composition.