title: Adipose tissue monomethyl branched-chain fatty acids and insulin sensitivity: Effects of obesity and weight loss.
abstract: OBJECTIVE
  An increase in circulating branched-chain amino acids (BCAA) is associated with insulin resistance. Adipose tissue is a potentially important site for BCAA metabolism. It was evaluated whether monomethyl branched-chain fatty acids (mmBCFA) in adipose tissue, which are likely derived from BCAA catabolism, are associated with insulin sensitivity.
  
  
  METHODS
  Insulin-stimulated glucose disposal was determined by using the hyperinsulinemic-euglycemic clamp procedure with stable isotope glucose tracer infusion in nine lean and nine obese subjects, and in a separate group of nine obese subjects before and 1 year after Roux-en-Y gastric bypass (RYGB) surgery (38% weight loss). Adipose tissue mmBCFA content was measured in tissue biopsies taken in the basal state.
  
  
  RESULTS
  Total adipose tissue mmBCFA content was ∼30% lower in obese than lean subjects (P=0.02) and increased by ∼65% after weight loss in the RYGB group (P=0.01). Adipose tissue mmBCFA content correlated positively with skeletal muscle insulin sensitivity (R(2) =35%, P=0.01, n=18).
  
  
  CONCLUSIONS
  These results demonstrate a novel association between adipose tissue mmBCFA content and obesity-related insulin resistance. Additional studies are needed to determine whether the association between adipose tissue mmBCFA and muscle insulin sensitivity is causal or a simple association.
authors.affiliation: Department of Biochemistry and Molecular Biology, Soochow University Medical College, Suzhou, China; Center for Human Nutrition, Washington University School of Medicine, St. Louis, Missouri, USA.
authors.forename: Xiong
authors.initials: X
authors.lastname: Su
authors.forename: Faidon
authors.initials: F
authors.lastname: Magkos
authors.forename: Dequan
authors.initials: D
authors.lastname: Zhou
authors.forename: J Christopher
authors.initials: JC
authors.lastname: Eagon
authors.forename: Elisa
authors.initials: E
authors.lastname: Fabbrini
authors.forename: Adewole L
authors.initials: AL
authors.lastname: Okunade
authors.forename: Samuel
authors.initials: S
authors.lastname: Klein
mesh_terms: D000273:Adipose Tissue / Q000378:metabolism*; D000328:Adult; D003430:Cross-Sectional Studies; D005227:Fatty Acids / Q000378:metabolism*; D005260:Female; D015390:Gastric Bypass; D015309:Glucose Clamp Technique; D006801:Humans; D007328:Insulin / Q000378:metabolism*; D007333:Insulin Resistance / Q000502:physiology; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000378:metabolism*; D015431:Weight Loss / Q000502:physiology*
chemical_list: D005227:Fatty Acids; D007328:Insulin