Association between the -174 G/C promoter polymorphism of the interleukin-6 gene and cardiovascular disease risk factors in Brazilian older women

Braz J Med Biol Res. 2008 Jan;41(1):47-53. doi: 10.1590/s0100-879x2006005000190. Epub 2007 Dec 17.

Abstract

In worldwide studies, interleukin-6 (IL-6) is implicated in age-related disturbances. The aim of the present report was to determine the possible association of IL-6 -174 C/G promoter polymorphism with the cytokine profile as well as with the presence of selected cardiovascular risk features. This was a cross-sectional study on Brazilian women aged 60 years or older. A sample of 193 subjects was investigated for impaired glucose regulation, diabetes, hypertension, and dyslipidemia. Genotyping was done by direct sequencing of PCR products. IL-6 and C-reactive protein were quantified by high-sensitivity assays. General linear regression models or the Student t-test were used to compare continuous variables among genotypes, followed by adjustments for confounding variables. The chi-square test was used to compare categorical variables. The genotypes were consistent with Hardy-Weinberg equilibrium proportions. In a recessive model, mean waist-to-hip ratio, serum glycated hemoglobin and serum glucose were markedly lower in C homozygotes (P = 0.001, 0.028, and 0.047, respectively). In a dominant hypothesis, G homozygotes displayed a trend towards higher levels of circulating IL-6 (P = 0.092). Non-parametric analysis revealed that impaired fasting glucose and hypertension were findings approximately 2-fold more frequent among G homozygous subjects (P = 0.042 and 0.043, respectively). Taken together, our results show that the IL-6 -174 G-allele is implicated in a greater cardiovascular risk. To our knowledge, this is the first investigation of IL-6 promoter variants and age-related disturbances in the Brazilian elderly population.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Biomarkers / blood
  • Brazil
  • Cardiovascular Diseases / blood
  • Cardiovascular Diseases / genetics*
  • Diabetes Mellitus / genetics
  • Epidemiologic Methods
  • Female
  • Gene Frequency
  • Genetic Predisposition to Disease / genetics*
  • Humans
  • Hypertension / genetics
  • Interleukin-6 / blood
  • Interleukin-6 / genetics*
  • Interleukin-6 / metabolism
  • Middle Aged
  • Polymerase Chain Reaction
  • Polymorphism, Genetic / genetics*
  • Promoter Regions, Genetic / genetics*

Substances

  • Biomarkers
  • Interleukin-6