title: Diabetes and cardiovascular disease outcomes in the metabolically healthy obese phenotype: a cohort study.
abstract: OBJECTIVE
  To determine the correlates of the "metabolically healthy obese" (MHO) phenotype and the longitudinal risks of diabetes and cardiovascular disease (CVD)/stroke associated with this phenotype.
  
  
  METHODS
  The North West Adelaide Health Study is a prospective cohort study of 4,056 randomly selected adults aged ≥ 18 years. Participants free of CVD/stroke and not underweight (n = 3,743) were stratified by BMI categories and metabolic risk, defined as having two or more International Diabetes Federation metabolic syndrome criteria, excluding waist circumference.
  
  
  RESULTS
  Correlates of the MHO (n = 454 [12.1%]) included smoking, socioeconomic disadvantage, and physical inactivity. Compared with metabolically healthy normal-weight subjects (n = 1,172 [31.3%]), the MHO were more likely to develop metabolic risk (15.5 vs. 33.1%, P < 0.001) and incident diabetes (odds ratio 2.09 [95% CI 0.87-5.03]) but not CVD/stroke (1.16 [0.58-2.29]) during 5.5-10.3 years of follow-up. These risks were not seen in MHO subjects maintaining metabolic health (n = 188 [67%]). Sustained metabolic health in obese participants was associated with age ≤ 40 years and lower waist circumference. Compared with the metabolically at-risk obese, MHO women demonstrated a significantly higher (mean [SE]) percentage of leg fat (49.9 [0.5] vs. 53.2 [0.7]) and lower waist circumference (104 [0.6] vs. 101 cm [0.8]), despite no significant differences in overall adiposity.
  
  
  CONCLUSIONS
  "Healthy" obesity was a transient state for one-third of subjects. Persistence of a MHO phenotype, which was associated with favorable outcomes, was related to younger age and a more peripheral fat distribution. The MHO phenotype may be sustained by promoting lower waist circumferences.
authors.affiliation: The Health Observatory, Discipline of Medicine, University of Adelaide, The Queen Elizabeth Hospital Campus,Woodville, South Australia, Australia. sarah.appleton@adelaide.edu.au
authors.forename: Sarah L
authors.initials: SL
authors.lastname: Appleton
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Seaborn
authors.forename: Renuka
authors.initials: R
authors.lastname: Visvanathan
authors.forename: Catherine L
authors.initials: CL
authors.lastname: Hill
authors.forename: Tiffany K
authors.initials: TK
authors.lastname: Gill
authors.forename: Anne W
authors.initials: AW
authors.lastname: Taylor
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Adams
mesh_terms: D000328:Adult; D001823:Body Composition; D002318:Cardiovascular Diseases / Q000209:etiology*; D015331:Cohort Studies; D003920:Diabetes Mellitus; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D009765:Obesity / Q000378:metabolism*; D050177:Overweight / Q000378:metabolism*; D010641:Phenotype; D012306:Risk; D055105:Waist Circumference