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OBJECTIVES:The six-minute walk test has been widely used to evaluate functional capacity and predict mortality in several populations. Thus, the aim of this study was to evaluate the prognostic value of the six-minute walk test for the life expectancy of end-stage renal disease patients.METHODS:Patients over 18 years old who underwent hemodialysis for at least six months were included. Patients with hemodynamic instability, smoking, chronic obstructive pulmonary disease, physical incapacity and acute myocardial stroke in the preceding three months were excluded.RESULTS:Fifty-two patients (54% males; 36±11 years old) were followed for 144 months. The distance walked in the six-minute walk test was a survival predictor for end-stage renal disease patients. In the multivariate analysis, for each 100 meters walked with a 100-meter increment, the hazard ratio was 0.53, with a 95% confidence interval of 0.37-0.74. There was a positive correlation between the distance walked in the six-minute walk test and peak oxygen consumption (r = 0.508). In the multivariate analysis, each year of dialysis treatment represented a 10% increase in death probability; in the severity index analysis, each point on the scale represented an 11% increase in the death risk.CONCLUSIONS:We observed that survival increased approximately 5% for every 100 meters walked in the six-minute walk test, demonstrating that the test is a viable option for evaluating the functional capacity in patients with end-stage renal disease.

This study aimed to evaluate the effects of neuromuscular electrical stimulation (NMES) on muscle strength and architecture, functional capacity, and endothelial function in patients with chronic kidney failure (CKF) on hemodialysis (HD). Twenty-one patients with CKF on HD were randomized into a control group (CG; n = 10) and neuromuscular electrical stimulation group (NMESG; n = 11) who received NMES in the quadriceps muscle for 8 weeks, 3 times/week (20-34 min) during HD sessions. The muscle strength of the lower limbs was evaluated by dynamometry and sit-and-stand test (SST); muscle architecture through ultrasonography; functional capacity by the distance covered in a 6-min walk test and the endothelial function by flow-mediated dilatation technique of the brachial artery. There was an increase in the strength of the lower limbs in the NMESG compared to the CG (dynamometry: 43.28 ± 16.94 vs. 35.84 ± 16.89, P = 0.006; SST: 16.10 ± 6.51 vs. 12.50 ± 4.7, P = 0.029). There was a significant reduction in pennation angles of the right vastus lateralis (RVL) and left vastus lateralis (LVL) in the CG when compared to the NMESG (RVL: 11.93 [10.70-15.11] vs. 13.57 [11.81-15.96], P = 0.039; LVL: 11.62 [9.00-14.20] vs. 15.52 [12.86-20.02], P = 0.042). There was no change in functional capacity and in the endothelial function for CG and NMESG, respectively. In conclusion, NMES increases muscle strength and has a protective effect against muscle atrophy of the lower limbs of patients with chronic kidney failure on HD.

The vascular endothelium plays a key role in arterial wall homeostasis by preventing atherosclerotic plaque formation. A primary causal factor of endothelial dysfunction is the reactive oxygen species. Aerobic exercise is ascribed as an important adjuvant therapy in endothelium-dependent cardiovascular disease. However, little is known about the effects of concurrent (aerobic + strength) training on that. For a comparison of the effects of aerobic and concurrent physical training on endothelial function, oxidative stress parameters and the immunoinflammatory activity of monocytes/macrophages, 20 adult male volunteers of middle age were divided into a concurrent training (CT) programme group and an aerobic training group. The glutathione disulphide to glutathione ratio (GSSG/GSH) and plasma lipoperoxide (LPO) levels, as well as flow-mediated dilation (FMD), monocyte/macrophage functional activity (zymosan phagocytosis), body lipid profiles, aerobic capacity (maximal oxygen uptake) and strength parameters (one-repetition maximum test), were measured before and after the exercise training programmes. The CT exhibited reduced acute effects of exercise on the GSSG/GSH ratio, plasma LPO levels and zymosan phagocytosis. The CT also displayed improved lipid profiles, glycaemic control, maximal oxygen uptake and one-repetition maximum test values. In both the aerobic training and the CT, training improved the acute responses to exercise, as inferred from a decrease in the GSSG/GSH ratios. The aerobic sessions did not alter basal levels of plasma LPO or macrophage phagocytic activity but improved FMD values as well as lipid profiles and glycaemic control. In summary, both training programmes improve systemic redox status and antioxidant defences. However, the aerobic training was more efficient in improving FMD in the individuals studied.

An important hypotensive effect was observed from the 1st session on and it was observed that the dose-response curve can be abrupt and decrescent, instead of flat.