title: Impaired skeletal muscle mitochondrial function in morbidly obese patients is normalized one year after bariatric surgery.
abstract: BACKGROUND
  Obesity and type 2 diabetes are associated with impaired skeletal muscle mitochondrial metabolism. As an intrinsic characteristic of an individual, skeletal muscle mitochondrial dysfunction could be a risk factor for weight gain and obesity-associated co-morbidities, such as type 2 diabetes. On the other hand, impaired skeletal muscle metabolism could be a consequence of obesity. We hypothesize that marked weight loss after bariatric surgery recovers skeletal muscle mitochondrial function.
  
  
  METHODS
  Skeletal muscle mitochondrial function as assessed by high-resolution respirometry was measured in 8 morbidly obese patients (body mass index [BMI], 41.3±4.7 kg/m(2); body fat, 48.3%±5.2%) before and 1 year after bariatric surgery (mean weight loss: 35.0±8.6 kg). The results were compared with a lean (BMI 22.8±1.1 kg/m(2); body fat, 15.6%±4.7%) and obese (BMI 33.5±4.2 kg/m(2); body fat, 34.1%±6.3%) control group.
  
  
  RESULTS
  Before surgery, adenosine diphosphate (ADP)-stimulated (state 3) respiration on glutamate/succinate was decreased compared with lean patients (9.5±2.4 versus 15.6±4.4 O2 flux/mtDNA; P<.05). One year after surgery, mitochondrial function was comparable to that of lean controls (after weight loss, 12.3±5.5; lean, 15.6±4.4 O2 flux/mtDNA). In addition, we observed an increased state 3 respiration on a lipid substrate after weight loss (10.0±3.2 versus 14.0±6.6 O2 flux/mtDNA; P< .05).
  
  
  CONCLUSIONS
  We conclude that impaired skeletal muscle mitochondrial function is a consequence of obesity that recovers after marked weight loss.
authors.affiliation: Department of Surgery, Maastricht University Medical Centre, Maastricht, the Netherlands; Department of Human Biology, School for Nutrition, Toxicology and Metabolism, NUTRIM, Maastricht, the Netherlands. Electronic address: guy.vijgen@gmail.com.
authors.forename: Guy H E J
authors.initials: GH
authors.lastname: Vijgen
authors.forename: Nicole D
authors.initials: ND
authors.lastname: Bouvy
authors.forename: Joris
authors.initials: J
authors.lastname: Hoeks
authors.forename: Sander
authors.initials: S
authors.lastname: Wijers
authors.forename: Patrick
authors.initials: P
authors.lastname: Schrauwen
authors.forename: Wouter D
authors.initials: WD
authors.lastname: van Marken Lichtenbelt
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001707:Biopsy, Needle; D001823:Body Composition; D015992:Body Mass Index; D016022:Case-Control Studies; D005260:Female; D005500:Follow-Up Studies; D015391:Gastroplasty / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008931:Mitochondria, Muscle / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000378:metabolism* / Q000502:physiology; D009767:Obesity, Morbid / Q000378:metabolism / Q000601:surgery*; D020127:Recovery of Function; D012016:Reference Values; D013997:Time Factors; D016896:Treatment Outcome; D015431:Weight Loss
keywords: Gastric banding; Morbid obesity; Skeletal muscle mitochondrial function; Weight loss