title: Adipose tissue morphology predicts improved insulin sensitivity following moderate or pronounced weight loss.
abstract: BACKGROUND
  Cross-sectional studies show that white adipose tissue hypertrophy (few, large adipocytes), in contrast to hyperplasia (many, small adipocytes), associates with insulin resistance and increased risk of developing type 2 diabetes. We investigated if baseline adipose cellularity could predict improvements in insulin sensitivity following weight loss.
  
  
  METHODS
  Plasma samples and subcutaneous abdominal adipose biopsies were examined in 100 overweight or obese individuals before and 10 weeks after a hypocaloric diet (7±3% weight loss) and in 61 obese subjects before and 2 years after gastric by-pass surgery (33±9% weight loss). The degree of adipose tissue hypertrophy or hyperplasia (termed the morphology value) in each individual was calculated on the basis of the relationship between fat cell volume and total fat mass. Insulin sensitivity was determined by homeostasis model assessment-estimated insulin resistance (HOMAIR).
  
  
  RESULTS
  In both cohorts at baseline, subjects with hypertrophy displayed significantly higher fasting plasma insulin and HOMAIR values than subjects with hyperplasia (P<0.0001), despite similar total fat mass. Plasma insulin and HOMAIR were normalized in both cohorts following weight loss. The improvement (delta insulin or delta HOMAIR) was more pronounced in individuals with hypertrophy, irrespective of whether adipose morphology was used as a continuous (P=0.0002-0.027) or nominal variable (P=0.002-0.047). Absolute adipocyte size associated (although weaker than morphology) with HOMAIR improvement only in the surgery cohort. Anthropometric measures at baseline (fat mass, body mass index, waist-to-hip ratio or waist circumference) showed no significant association with delta insulin or delta HOMAIR.
  
  
  CONCLUSIONS
  In contrast to anthropometric variables or fat cell size, subcutaneous adipose morphology predicts improvement in insulin sensitivity following both moderate and pronounced weight loss in overweight/obese subjects.
authors: Department of Medicine (H7), Karolinska Institutet, Karolinska University Hospital, Karolinska University Hospital, Huddinge, Stockholm, Sweden.
authors: D
authors: D
authors: Eriksson-Hogling
authors: Department of Medicine (H7), Karolinska Institutet, Karolinska University Hospital, Karolinska University Hospital, Huddinge, Stockholm, Sweden.
authors: D P
authors: DP
authors: Andersson
authors: Department of Medicine (H7), Karolinska Institutet, Karolinska University Hospital, Karolinska University Hospital, Huddinge, Stockholm, Sweden.
authors: J
authors: J
authors: Bäckdahl
authors: Department of Medicine (H7), Karolinska Institutet, Karolinska University Hospital, Karolinska University Hospital, Huddinge, Stockholm, Sweden.
authors: J
authors: J
authors: Hoffstedt
authors: Department of Medicine (H7), Karolinska Institutet, Karolinska University Hospital, Karolinska University Hospital, Huddinge, Stockholm, Sweden.
authors: S
authors: S
authors: Rössner
authors: Department of Surgery, Karolinska Institutet, Ersta Hospital, Stockholm, Sweden.
authors: A
authors: A
authors: Thorell
authors: Department of Medicine (H7), Karolinska Institutet, Karolinska University Hospital, Karolinska University Hospital, Huddinge, Stockholm, Sweden.
authors: E
authors: E
authors: Arner
authors: Department of Medicine (H7), Karolinska Institutet, Karolinska University Hospital, Karolinska University Hospital, Huddinge, Stockholm, Sweden.
authors: P
authors: P
authors: Arner
authors: Department of Medicine (H7), Karolinska Institutet, Karolinska University Hospital, Karolinska University Hospital, Huddinge, Stockholm, Sweden.
authors: M
authors: M
authors: Rydén
mesh_terms: D017667:Adipocytes / Q000378:metabolism / Q000473:pathology*; D052436:Adipose Tissue, White / Q000378:metabolism / Q000473:pathology*; D000328:Adult; D050110:Bariatric Surgery; D001786:Blood Glucose / Q000378:metabolism; D015992:Body Mass Index; D049108:Cell Enlargement; D015331:Cohort Studies; D003924:Diabetes Mellitus, Type 2 / Q000209:etiology* / Q000378:metabolism / Q000517:prevention & control; D004038:Diet, Reducing; D005260:Female; D006801:Humans; D007249:Inflammation / Q000209:etiology* / Q000378:metabolism; D008297:Male; D009765:Obesity / Q000150:complications* / Q000378:metabolism / Q000473:pathology / Q000601:surgery; D016032:Randomized Controlled Trials as Topic; D013548:Sweden; D015431:Weight Loss
chemical_list: D001786:Blood Glucose