title: Impaired muscle oxygen metabolism in uremic children: improved after renal transplantation.
abstract: BACKGROUND
  The purpose of this study is to clarify skeletal muscle oxidative metabolism in children with end-stage renal disease (ESRD) before and after renal transplantation.
  
  
  METHODS
  We examined muscle oxygenation and metabolism by using noninvasive near-infrared spectroscopy in 10 patients (age, 12.4 +/- 3.1 years) 1 week before and 4 weeks after renal transplantation and in 10 controls (age, 12.8 +/- 2.6 years) during submaximal hand-grip exercise using the flexor digitorum superficialis muscle. We used 2 indicators to evaluate muscle metabolism. The rate of initial decrease in hemoglobin/myoglobin deoxygenation during arterial occlusion after exercise relative to the value at rest (S2/S1) was used as an indicator of mitochondrial oxygen consumption, whereas recovery time (TR) after exercise was used as an indicator of oxygen delivery to the muscle and aerobic capacity.
  
  
  RESULTS
  S2/S1 and TR after exercise were significantly lower in patients before renal transplantation compared with the control group (P < 0.05). S2/S1 and TR after exercise improved significantly after renal transplantation (P < 0.01, P < 0.05) and were not significantly different from those of controls.
  
  
  CONCLUSIONS
  Oxidative metabolism in skeletal muscle during exercise is impaired in children with ESRD and recovers after renal transplantation.
authors.affiliation: Department of Pediatric Nephrology, Tokyo Women's Medical University, Japan. naoko_pine@msn.com
authors.forename: Naoko
authors.initials: N
authors.lastname: Matsumoto
authors.forename: Shiro
authors.initials: S
authors.lastname: Ichimura
authors.forename: Takafumi
authors.initials: T
authors.lastname: Hamaoka
authors.forename: Takuya
authors.initials: T
authors.lastname: Osada
authors.forename: Motoshi
authors.initials: M
authors.lastname: Hattori
authors.forename: Sanpei
authors.initials: S
authors.lastname: Miyakawa
mesh_terms: D000293:Adolescent; D002648:Child; D015444:Exercise / Q000502:physiology; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000150:complications / Q000378:metabolism* / Q000601:surgery*; D016030:Kidney Transplantation; D008297:Male; D018482:Muscle, Skeletal / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism*; D019265:Spectroscopy, Near-Infrared; D016896:Treatment Outcome; D014511:Uremia / Q000209:etiology
chemical_list: D010100:Oxygen