title: A common polymorphism near the interleukin-6 gene modifies the association between dietary fat intake and insulin sensitivity.
abstract: BACKGROUND
  Increasing evidence suggests a role for inflammation in the development of type 2 diabetes. Elevated levels of inflammatory cytokines, including interleukin-6, have been associated with insulin resistance, and dietary lipids can increase cytokine production. The objective of this study was to determine whether a single nucleotide polymorphism near the IL6 gene (rs7801406) modifies the relationship between dietary fat and markers of insulin sensitivity.
  
  
  METHODS
  Subjects were healthy men and women aged 20-29 years from the Toronto Nutrigenomics and Health Study. Dietary intake was estimated using a one-month semiquantitative food frequency questionnaire. Fasting blood samples were taken for genotyping and biomarker measurement.
  
  
  RESULTS
  The single nucleotide polymorphism was not associated with any of the measures of insulin sensitivity. However, it modified the relationship between total dietary fat and the homeostasis model assessment of insulin resistance (P = 0.053 for interaction). Total fat intake was positively related to HOMA-IR in individuals homozygous for the G allele (β = 0.005 ± 0.002, P = 0.03), but not among heterozygotes. There was an inverse relationship between total fat intake and HOMA-IR in individuals who were homozygous for the A allele (β = -0.012 ± 0.006, P = 0.047).
  
  
  CONCLUSIONS
  These findings suggest that dietary fat influences insulin sensitivity differently depending on genotype.
authors.affiliation: Department of Nutritional Sciences, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Cristina
authors.initials: C
authors.lastname: Cuda
authors.forename: Bibiana
authors.initials: B
authors.lastname: Garcia-Bailo
authors.forename: Mohamed
authors.initials: M
authors.lastname: Karmali
authors.forename: Ahmed
authors.initials: A
authors.lastname: El-Sohemy
authors.forename: Alaa
authors.initials: A
authors.lastname: Badawi