title: The trends of metabolic syndrome in normal-weight Tehranian adults.
abstract: BACKGROUND
  In recent decades, more attention has been directed to the clustering of cardiometabolic risk factors in normal-weight adults. This study investigates trends of the prevalence of metabolic syndrome (MetS) in a normal-weight Tehranian adult population during 6.6 years of follow-up.
  
  
  METHODS
  In this population-based cohort study of 5,269 participants aged ≥ 20 years during the 3 phases (1999-2001, 2002-2005 and 2005-2008) of the Tehran Lipid and Glucose Study, we selected 390 males and 358 females with a normal body mass index (18.5-24.9) during all 3 periods of follow-up. MetS was defined according to the International Diabetes Federation criteria, and waist circumference (WC) cut points were ≥ 89 cm for males and ≥ 91 cm for females.
  
  
  RESULTS
  The overall prevalence of MetS increased from 2.3 and 4.0% in phases I and II to 9.6% in phase III. This trend was significant in males (p < 0.001) but not in females (p = 0.6). No significant changes in components of MetS were seen, except in WC among males. In the 3 study phases, prevalence of abdominal obesity was 3.1, 18.5 and 36.2% in males, respectively.
  
  
  CONCLUSIONS
  There was a dramatic 4-fold increase in the prevalence of MetS in the Tehranian normal-weight adult population, highlighting the importance of MetS components, especially of WC, in normal-weight adult males.
authors.affiliation: Obesity Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University, Tehran, Iran. fhospanah @ endocrine.ac.ir
authors.forename: Farhad
authors.initials: F
authors.lastname: Hosseinpanah
authors.forename: Maryam
authors.initials: M
authors.lastname: Barzin
authors.forename: Parisa
authors.initials: P
authors.lastname: Amiri
authors.forename: Fereidoun
authors.initials: F
authors.lastname: Azizi
mesh_terms: D000328:Adult; D000368:Aged; D015992:Body Mass Index; D002318:Cardiovascular Diseases / Q000453:epidemiology; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D005260:Female; D005500:Follow-Up Studies; D019456:Health Transition; D006801:Humans; D007492:Iran / Q000453:epidemiology; D008297:Male; D024821:Metabolic Syndrome / Q000453:epidemiology*; D008875:Middle Aged; D056128:Obesity, Abdominal / Q000453:epidemiology; D015995:Prevalence; D011446:Prospective Studies; D012307:Risk Factors; D012737:Sex Factors; D055105:Waist Circumference; D055815:Young Adult