title: Gastric bypass in Type 2 diabetes with BMI < 30: weight and weight loss have a major influence on outcomes.
abstract: OBJECTIVE
  To assess factors influencing glycaemic control following gastric bypass surgery in patients with Type 2 diabetes and BMI< 30 kg/m(2) .
  
  
  METHODS
  Prospective longitudinal study of 103 patients with inadequate glycaemic control who underwent gastric bypass surgery at Soonchunhyang University, Seoul, Korea (n = 66) and Min-Sheng General Hospital, Taipei, Taiwan (n = 37). Procedures were performed August 2009 to January 2011. Key outcome measures were excellent glycaemic control of Type 2 diabetes defined as HbA1c < 42 mmol/mol (≤6%); inadequate response defined as HbA1c > 53 mmol/mol (> 7%). Analysis was conducted using binary logistic regression, and cut-points obtained from receiver operator characteristics.
  
  
  RESULTS
  Excellent glycaemic control was achieved in 31 (30%) at 1 year. Diabetes duration of < 7 years and BMI > 27 kg/m(2) provided independent predictors and useful cut-points. Likelihood of excellent glycaemic control for an individual could be estimated using loge (Odds) = -6.7 + (0.26 × BMI) + (-1.2 × diabetes duration). Baseline BMI of < 27 kg/m(2) and baseline C-peptide of < 2.0ng/ml, best predicted a poor glycaemic response. In those with favourable baseline characteristics percentage weight loss (%WL) had a dominant influence on glycaemic outcomes. Baseline C-peptide (> 2.4 ng/ml) and subsequent percentage weight loss (> 16%) were associated with excellent glycaemic control. Higher BMI was associated with greater percentage weight loss.
  
  
  CONCLUSIONS
  In patients with Type 2 diabetes and BMI < 30 kg/m(2) , glycaemic response to gastric bypass is predicted by higher baseline BMI, shorter disease duration and higher fasting C-peptide. Post-surgery weight loss has a dominant effect. Baseline BMI and weight loss have a major influence on outcomes.
authors.affiliation: Baker IDI Heart & Diabetes Institute, Melbourne, Victoria, Australia.
authors.forename: J B
authors.initials: JB
authors.lastname: Dixon
authors.forename: K-Y
authors.initials: KY
authors.lastname: Hur
authors.forename: W-J
authors.initials: WJ
authors.lastname: Lee
authors.forename: M-J
authors.initials: MJ
authors.lastname: Kim
authors.forename: K
authors.initials: K
authors.lastname: Chong
authors.forename: S-C
authors.initials: SC
authors.lastname: Chen
authors.forename: N-E
authors.initials: NE
authors.lastname: Straznicky
authors.forename: P
authors.initials: P
authors.lastname: Zimmet
mesh_terms: D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000378:metabolism; D015992:Body Mass Index; D002096:C-Peptide / Q000378:metabolism; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000601:surgery*; D005215:Fasting / Q000097:blood; D005260:Female; D015390:Gastric Bypass / Q000379:methods*; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D010535:Laparoscopy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D016896:Treatment Outcome; D015431:Weight Loss / Q000502:physiology*; D055815:Young Adult
chemical_list: D001786:Blood Glucose; D002096:C-Peptide; D006442:Glycated Hemoglobin