Anabolic interventions in ESRD

ESRD produces a chronic catabolic state that results in significant skeletal muscle atrophy, weakness, and physical dysfunction. Any intervention that can ameliorate this process can significantly improve quality of life. Some studies have shown that endurance exercise training, even at low intensities, may exhibit anabolic effects and improved physical function. However, resistance exercise training is of primary interest as an anabolic intervention because it is the mode of exercise that is most efficacious in stimulating anabolic responses, improved muscle performance, and physical function. A relatively small number of controlled trials of resistance training in ESRD patients have failed to show significant changes in LBM, although some studies have shown significant improvements in other markers of anabolism. Increases in muscle strength with resistance training are typical but improved physical function, either by objective measurement or self-report, are equivocal. Study durations, loads used during training, and relatively small sample sizes may in part explain the inability of previous studies to observe more substantial changes in LBM and physical function. Androgens and growth hormone have been shown to significantly improve LBM and strength, although longer-term studies for safety and efficacy are necessary before their general recommendation for patients with ESRD.