Disfunção metaborreflexa muscular ao exercício físico em pacientes com cirrose hepática

Abstract

Introduction: Studies show an important hemodynamic change in cirrhotic individuals, which is related to the severity of liver disease. This fact incites the interest in knowing the behavior of these variables during a physiological stimulus situation such as physical exercise. Objective: To evaluate the muscular metaborreflex of cirrhotic individuals in response to physical exercise. Methods: Fifteen cirrhotic subjects (CH), classified as severity in Child-Pugh A, B and C and 15 healthy controls (CS) of both sexes, matched for age (51 ± 13 vs. 42 ± 14 years, p = 0.09, respectively). The maximum voluntary contraction force (CVM) was calculated by the arithmetic mean of three attempts in the hand grip dynamometer (JAMAR). Blood pressure measured minute by minute (oscillometric method - DIXTAL2023), and forearm muscle blood flow (venous occlusion plethysmography - Hokanson) were recorded simultaneously for 3 baseline minutes followed by 3 minutes of isometric physical exercise performed at 30% of CVM . Muscle vasodilation of the forearm was calculated by dividing muscle blood flow by mean arterial pressure. For analysis of the metaborreflex contribution in this hemodynamic behavior, the cuff placed on the dominant arm of the volunteer was inflated to supra-systolic pressure for 2 consecutive minutes followed. Metaborreflex sensitivity was calculated by the absolute delta between the 1st and 2nd minute of circulatory occlusion after exercise in the dominant arm and the mean of the basal register. It was adopted as significant p≤0.05. Results: There were 9 Child-Pugh A patients, 4 Child- Pugh B patients and 2 Child-Pugh C patients. At rest both groups had similar levels of hemodynamic variables. Systolic blood pressure (SBP) Diastolic blood pressure (DBP), mean arterial pressure (P = 0.4, p = 0.6, P = 0.4, p = 0.11, p = 0, 15 and p = 0.12 respectively). During exercise, however, the CH group presented a significant loss of blood pressure response. WFP was significantly lower in the absolute second minute delta (interaction effect p = 0.01). In addition, the SBP, PAD and PAM variables presented an absolute delta of minute 3 significantly lower in the CH group (interaction effect p = 0.05, p = 0.01, p = 0.01, respectively). This behavior can be explained by the involvement of the muscular group meta-reflexion of the CH Group for the variables PAS, DBP and MAP in the first minute delta of the occlusion (p = 0.02, p = 0.03 and p <0.00, respectively), and also in the second minute delta occlusion (p <0.00, p <0.00 and p = 0.04). Finally, both groups presented normal physiological behavior of the variables CF, FS and Cd during the 3 minutes of physical exercise. Conclusion: Cirrhotic individuals present an important impairment in blood pressure regulation during exercise, which can be explained, at least in part, by a depressed metaborreflex muscular response.