title: Waist circumference to assess reversal of insulin resistance following weight reduction after bariatric surgery: cohort and cross-sectional studies.
abstract: OBJECTIVE
  To validate the use of waist circumference to assess reversal of insulin resistance after weight loss induced by bariatric surgery.
  
  
  METHODS
  In cross-sectional studies, threshold values for insulin resistance were determined with homeostasis model assessment of insulin resistance (HOMA-IR) (algorithm based on fasting plasma glucose and insulin) in 1018 lean subjects and by hyperinsulinemic euglycemic clamp (clamp) in 26 lean women. In a cohort study on 211 patients scheduled for bariatric surgery, HOMA-IR and waist circumference were measured before and 1.5-3 years after weight reduction. In a subgroup of 53 women, insulin sensitivity was also measured using clamp.
  
  
  RESULTS
  The threshold for insulin resistance (90th percentile) was 2.21 (mg dl(-1) fasting glucose × mU l(-1) fasting insulin divided by 405) for HOMA-IR and 6.118 (mg glucose per kg body weight per minute) for clamp. Two methods to assess reversal of insulin resistance by measuring waist circumference were used. A single cutoff value to <100 cm for waist circumference was associated with reversal of insulin resistance with an odds ratio (OR) of 49; 95% confidence interval (CI)=7-373 and P=0.0002. Also, a diagram based on initial and weight loss-induced changes in waist circumference in patients turning insulin sensitive predicted reversal of insulin resistance following bariatric surgery with a very high OR (32; 95% CI=4-245; P=0.0008). Results with the clamp cohort were similar as with HOMA-IR analyses.
  
  
  CONCLUSIONS
  Reversal of insulin resistance could either be assessed by a diagram based on initial waist circumference and reduction of waist circumference, or by using 100 cm as a single cutoff for waist circumference after weight reduction induced by bariatric surgery.
authors.affiliation: Department of Medicine, Karolinska Institutet, Karolinska University Hospital Clinic for Endocrinology and Metabolism, Stockholm, Sweden.
authors.forename: D P
authors.initials: DP
authors.lastname: Andersson
authors.affiliation: Department of Medicine, Karolinska Institutet, Karolinska University Hospital Clinic for Endocrinology and Metabolism, Stockholm, Sweden.
authors.forename: H
authors.initials: H
authors.lastname: Wahrenberg
authors.affiliation: Department of Medicine, Ersta Hospital, Stockholm, Sweden.
authors.forename: E
authors.initials: E
authors.lastname: Toft
authors.affiliation: Department of Medicine, Ersta Hospital, Stockholm, Sweden.
authors.forename: V
authors.initials: V
authors.lastname: Qvisth
authors.affiliation: Department of Medicine, Karolinska Institutet, Karolinska University Hospital Clinic for Endocrinology and Metabolism, Stockholm, Sweden.
authors.forename: P
authors.initials: P
authors.lastname: Löfgren
authors.affiliation: Department of Medicine, Karolinska Institutet, Karolinska University Hospital Clinic for Endocrinology and Metabolism, Stockholm, Sweden.
authors.forename: K
authors.initials: K
authors.lastname: Hertel
authors.affiliation: Department of Medicine, Karolinska Institutet, Karolinska University Hospital Clinic for Endocrinology and Metabolism, Stockholm, Sweden.
authors.forename: B-M
authors.initials: BM
authors.lastname: Leijonhufvud
authors.affiliation: Department of Surgery, Ersta Hospital, Stockholm, Sweden.
authors.forename: A
authors.initials: A
authors.lastname: Thorell
authors.affiliation: Department of Clinical Sciences, Danderyd Hospital, Karolinska Institutet, Stockholm, Sweden.
authors.forename: E
authors.initials: E
authors.lastname: Näslund
authors.affiliation: Department of Medicine, Karolinska Institutet, Karolinska University Hospital Clinic for Endocrinology and Metabolism, Stockholm, Sweden.
authors.forename: P
authors.initials: P
authors.lastname: Arner
mesh_terms: D000328:Adult; D050110:Bariatric Surgery; D001786:Blood Glucose / Q000378:metabolism; D015992:Body Mass Index; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D005215:Fasting; D005260:Female; D015309:Glucose Clamp Technique; D006706:Homeostasis; D006801:Humans; D007333:Insulin Resistance; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000378:metabolism / Q000601:surgery*; D055105:Waist Circumference; D015431:Weight Loss
chemical_list: D001786:Blood Glucose