Efeitos benéficos do treinamento resistido com e sem restrição de fluxo sanguíneo para pacientes com doença renal crônica: proposição do eixo músculo-cérebro- rins

Abstract

Background: Recently, the scientific community began to discover and understand the vital role of skeletal muscles as an endocrine organ and in maintaining the health of the human body. The rhythmic muscle contraction promoted by physical exercise induces the expression, production, and release of exerkines which, acting in an autocrine/paracrine and endocrine manner, promote interorgan communication and metabolic regulation and, therefore, the health of human body tissues. On the other hand, sarcopenia is associated with several pathological outcomes, a worse prognosis, and mortality. Specifically, in patients with chronic kidney disease, sarcopenia is highly prevalent, which decreases their quality of life and makes them more likely to have high levels of depression. In this sense, resistance training can be an important ally, given its specificity, to mitigate and/or reverse these harmful effects. It is conjectured that resistance training is a vehicle for promoting muscular and systemic health, inducing protective effects and metabolic regulators that can contribute positively to the treatment of patients with chronic kidney disease. Furthermore, it is speculated that there is a muscle-brain-kidney axis. However, the effects of resistance training as an adjunct to the treatment of these patients remain poorly understood. Especially those related to uremic sarcopenia, glycemic and lipemic homeostasis, cardiac autonomic function, redox balance, inflammatory profile, and estimated glomerular filtration rate (eGFR). Objective: We aimed to analyze the influence of conventional resistance training (RT) and resistance training with blood flow restriction (RT+RF) on glycemic and lipemic homeostasis, immunometabolic profile, cardiac redox and autonomic balance, symptoms of depression, and quality of life of patients with chronic kidney disease. Methods: Initially, we evaluated patients with CKD (n=105; 33 women) on conservative treatment. They were randomly separated into a control group (CTL, n=35; 11F), resistance training (RT, n=35; 12F), and resistance training with flow restriction (RT+BFR, n=35; 10F). RT and RT+BFR groups underwent progressive resistance training lasting 6 months, performed 3 times a week, on non-consecutive days and training loads adjusted every 2 months, namely, RT 50%-60%-70 % of 1RM and RT+BFR 30%-40%-50% of 1 RM with a fixed number of repetitions. Patients were supervised by strength and conditioning professionals during every training session. Renal function was assessed by estimated glomerular filtration rate (creatinine and cystatin) and serum albumin. Metabolic, hormonal, and inflammatory biomarkers and redox status were analyzed in blood samples donated by patients. Heart rate variability was recorded using Polar RS-800 and data was analyzed in time and frequency domains using the Kubios app. Additionally, a post hoc analysis of individual responses was performed using the typical error and the smallest worthwhile change, calculated according to Swinton, also principal component analysis (PCA) to identify the direction and contribution of each variable to the maintenance of the estimated glomerular filtration rate and verify which of them were related to the intervention groups. Intend to assess the relationship between RT, quality of life, and symptoms of depression, we selected patients under hemodialysis treatment and randomly divided them into control (CTL, n=76/36F) and RT (n=81/35F) groups. The RT group completed 6 months of training, three times a week on a non-consecutive day under the supervision of a strength and conditioning professional, immediately before the hemodialysis session. Training loads were adjusted using the OMNI-RES scale. The redox profile and BDNF levels were evaluated in blood samples donated by the patients. Quality of life was assessed using the Medical Outcomes Questionnaire – SF36 and the Beck Depression Inventory was applied. Results: Patients under conservative treatment, six months of RT and RT+BFR were similarly efficient in improving glycemic homeostasis, levels of glucoseuptake hormone mediators (exercise), antioxidant defense, and cardiac autonomic function; in addition to decreasing the values of pro-inflammatory, fibrotic, and oxidative biomarkers; together these findings seem to have contributed to delay the drop in the estimated glomerular filtration rate. In patients undergoing hemodialysis, RT induced an increase in BNDF and tempers the redox balance, improving quality of life and reducing symptoms of depression. Conclusion. RT and RT+BFR help to improve the treatment of chronic kidney disease. In patients under conservative treatment, RT and RT+BFR contributed to metabolic regulation and preservation of renal function. For patients undergoing hemodialysis treatment, RT improved aspects related to mental health and attenuation of the symptoms resulting from the disease. Thus, we suggest that progressive RT and RT+BFR be included in the treatment of patients with chronic kidney disease regardless of stage.