title: Sex differences in the association between serum ferritin and fasting glucose in type 2 diabetes among South Asian Surinamese, African Surinamese, and ethnic Dutch: the population-based SUNSET study.
abstract: OBJECTIVE
  Moderately elevated iron stores below the levels commonly associated with hemochromatosis have been implicated in the etiology of diabetes. Studies suggest that iron status (measured by serum ferritin) differs significantly according to sex, but inconsistent findings have been reported. Our aim is to test the association between serum ferritin and the prevalence of type 2 diabetes and fasting glucose concentrations in a population-based, multiethnic, cross-sectional study including men and women of African Surinamese, South Asian Surinamese, and ethnic Dutch origin.
  
  
  METHODS
  We analyzed data on 508 ethnic Dutch, 597 African Surinamese, and 339 South Asian Surinamese aged 35-60 years. Type 2 diabetes was defined as a fasting plasma glucose level ≥7.0 mmol/L or a self-reported diagnosis.
  
  
  RESULTS
  Serum ferritin was positively associated with type 2 diabetes and fasting glucose, but differences in the associations according to sex were observed. Serum ferritin concentration was positively associated with type 2 diabetes among women in all ethnic groups (odds ratio [OR] ethnic Dutch: 1.07 [95% CI 1.01-1.13]; OR South Asian Surinamese: 1.05 [1.00-1.10]; OR African Surinamese: 1.05 [1.01-1.10]), but not among men. Serum ferritin was also more strongly associated with fasting glucose in women than in men. Moreover, the magnitude of sex differences in the association between serum ferritin and fasting glucose, but not type 2 diabetes, was more pronounced in the African Surinamese group than in the other ethnic groups (P for interaction ≤0.0001).
  
  
  CONCLUSIONS
  We found a positive association between serum ferritin and type 2 diabetes and fasting glucose in our multiethnic population, which appeared stronger among women than men. Further evaluation of the variation in sex differences between ethnic groups is warranted, particularly among the African Surinamese, to understand the mechanisms behind these sex differences.
authors.affiliation: Department of Public Health, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands. l.h.dekker@amc.uva.nl
authors.forename: Louise H
authors.initials: LH
authors.lastname: Dekker
authors.forename: Mary
authors.initials: M
authors.lastname: Nicolaou
authors.forename: Daphne L
authors.initials: DL
authors.lastname: van der A
authors.forename: Wim B
authors.initials: WB
authors.lastname: Busschers
authors.forename: Lizzy M
authors.initials: LM
authors.lastname: Brewster
authors.forename: Marieke B
authors.initials: MB
authors.lastname: Snijder
authors.forename: Karien
authors.initials: K
authors.lastname: Stronks
authors.forename: Irene G M
authors.initials: IG
authors.lastname: van Valkengoed
mesh_terms: D000328:Adult; D000368:Aged; D044383:Black People; D001786:Blood Glucose / Q000378:metabolism*; D003924:Diabetes Mellitus, Type 2 / Q000097:blood*; D005215:Fasting / Q000097:blood*; D005260:Female; D005293:Ferritins / Q000097:blood*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012737:Sex Factors; D044465:White People
chemical_list: D001786:Blood Glucose; D005293:Ferritins