Effects of Different Exercises on Physical Function, Dialysis Adequacy, and Health-Related Quality of Life in Maintenance Hemodialysis Patients: A Systematic Review and Network Meta-Analysis

<b><i>Background:</i></b> Clinical guidelines recommend exercise training for patients undergoing maintenance hemodialysis (MHD). However, the effectiveness of different types of exercise remains uncertain. <b><i>Objectives:</i></b> The aims of the study were to compare and rank the effect of different types of exercise on walking capacity, cardiorespiratory fitness, dialysis adequacy, and health-related quality of life (HRQOL) in patients undergoing MHD. <b><i>Methods:</i></b> Eight databases (four English and four Chinese) were searched from inception to January 1, 2022. Randomized controlled trials evaluating the efficacy of different exercises for patients undergoing MHD were included. Two independent reviewers screened the literature, extracted data, assessed the risk of bias, and evaluated the certainty of evidence. A frequentist random-effect network meta-analysis was conducted. <b><i>Results:</i></b> Ninety trials with 4,084 participants comparing 15 types of exercise were included, reporting on the six-minute walking test (45 trials), peak oxygen uptake (22 trials), dialysis adequacy (30 trials), and HRQOL (23 trials). Network meta-analysis showed that the most effective intervention for walking capacity was intradialytic aerobic exercise combined with blood flow restriction with a mean difference and 95% confidence interval of 97.35 (11.89–182.81), for peak oxygen uptake it was non-intradialytic combined aerobic and resistance exercise with a value of 4.35 (2.25–6.44), for dialysis adequacy it was intradialytic combined aerobic and resistance exercise with a value of 0.17 (0.06–0.28), for the physical component summary of HRQOL it was intradialytic aerobic exercise with a value of 4.93 (2.31–7.54), and for the mental component summary of HRQOL it was non-intradialytic combined aerobic and resistance exercise with a value of 6.36 (0.45–12.27). Ultimately, intradialytic combined aerobic and resistance exercise could improve all the above outcomes compared to usual care. <b><i>Conclusions:</i></b> This study concluded that intradialytic combined aerobic and resistance exercise is optimal for MHD patients due to its significant positive effects on multiple outcomes. Walking capacity can be further enhanced by combining blood flow restriction with exercise. For improving dialysis adequacy, intradialytic exercise proves to be more effective than non-intradialytic exercise. Further well-designed clinical trials are needed to investigate the effects of exercise with varying durations, intensities, and frequencies.