Analysis of G(-174)C IL-6 polymorphism and plasma concentrations of inflammatory markers in patients with type 2 diabetes and peripheral arterial disease

J Clin Pathol. 2006 Feb;59(2):211-5. doi: 10.1136/jcp.2004.025452.

Abstract

Aims: To determine whether the G(-174)C interleukin 6 (IL-6) polymorphism influences the development of peripheral arterial disease (PAD) in individuals with type 2 diabetes. This was investigated by comparing the distribution of G(-174)C genotypes between patients with type 2 diabetes and PAD (PAD+) and those with type 2 diabetes but without PAD (PAD-). Plasma concentrations of IL-6, fibrinogen, C reactive protein (CRP), and vascular endothelial growth factor (VEGF) were also compared in PAD+ and PAD- patients.

Methods: Blood samples were collected from 146 PAD+ and 144 PAD- patients. SfaNI was used to determine the G(-174)C genotype. Plasma concentrations of IL-6, fibrinogen, CRP, and VEGF were measured by an enzyme linked immunosorbent assay.

Results: The GG genotype was more common in PAD+ patients than in PAD- patients. PAD+ patients also had increased mean plasma concentrations of IL-6, fibrinogen, CRP, and VEGF compared with PAD- patients. Mean plasma concentrations of IL-6, fibrinogen, and CRP in both PAD+ and PAD- patients were higher in those with the GG genotype than in those with the GC or CC genotypes. In contrast, mean plasma concentrations of VEGF in PAD+ and PAD- patients were not significantly different between those with different G(-174)C genotypes.

Conclusions: These results support a model in which the GG genotype promotes PAD development among individuals with type 2 diabetes by inducing increased release of IL-6. Higher concentrations of IL-6 among those with the GG genotype is associated with increased plasma concentrations of fibrinogen and CRP.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • C-Reactive Protein / analysis
  • Diabetes Mellitus, Type 2 / blood
  • Diabetes Mellitus, Type 2 / genetics*
  • Diabetic Angiopathies / blood
  • Diabetic Angiopathies / genetics*
  • Female
  • Fibrinogen / analysis
  • Genetic Predisposition to Disease
  • Genotype
  • Humans
  • Interleukin-6 / blood
  • Interleukin-6 / genetics*
  • Male
  • Middle Aged
  • Peripheral Vascular Diseases / blood
  • Peripheral Vascular Diseases / genetics*
  • Polymorphism, Genetic*
  • Vascular Endothelial Growth Factor A / blood

Substances

  • Interleukin-6
  • Vascular Endothelial Growth Factor A
  • Fibrinogen
  • C-Reactive Protein