Peak oxygen uptake in ESRD.

摘要

In their intriguing study of peak oxygen uptake in patients with end-stage renal disease, Painter et al discuss factors that may limit the extraction of oxygen from the blood by working skeletal muscle. These include abnormal blood flow to muscle, decreased capillary density within muscle, increased diffusion distances from capillary to myofibril, and abnormal oxidative enzyme level or activity. During a study of anemia correction and exercise training among patients receiving hemodialysis, we performed muscle biopsies and utilized electron microscopy in addition to standard histology. We identified thickened capillary endothelium, thickened basement membranes, and interstitial electron-dense deposits, all of which may further impede the diffusion of oxygen from the circulation to the mitochondria of myocytes.