Plasma interleukin-6, tumour necrosis factor alpha and blood cytokine production in type 2 diabetes

Life Sci. 2000 Jun 8;67(3):291-300. doi: 10.1016/s0024-3205(00)00622-6.


Type 2 diabetes is associated with increased circulating concentrations of markers of the acute-phase response and interleukin-6 (IL-6). An augmented acute-phase response may be a mechanism which explains many of the clinical and biochemical features of type 2 diabetes and its complications. We sought to confirm that circulating concentrations of the cytokine acute-phase mediators IL-6 and tumour necrosis factor alpha [TNFalpha] are elevated in type 2 diabetes, and investigated blood as a source of cytokines in type 2 diabetes. Blood samples from 20 type 2 diabetic and 17 age-matched healthy subjects were incubated in vitro for 24 hr with and without lipopolysaccharide (LPS) stimulation and secreted cytokines measured. Plasma IL-6 and TNFalpha were significantly increased in type 2 diabetes compared to normal subjects. However, basal production of IL-6 and TNFalpha in cultured diabetic blood was markedly depressed in comparison with non-diabetic samples. IL-6 and TNFalpha production was increased in blood in response to LPS, reaching similar levels in diabetic and non-diabetic subjects, though IL-6 was slightly but significantly higher in controls. We conclude that circulating levels of IL-6 and TNFalpha are increased in type 2 diabetes but there is downregulation of basal cytokine production in blood cells in type 2 diabetes. Blood has the capacity to produce cytokines in diabetes which contribute to the augmented acute-phase response, but the main source of the increased plasma IL-6 and TNFalpha concentrations may be from non-circulating cells.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acute-Phase Reaction / blood
  • Diabetes Mellitus, Type 2 / blood*
  • Female
  • Humans
  • Immunoenzyme Techniques
  • Interleukin-6 / biosynthesis*
  • Interleukin-6 / blood*
  • Lipopolysaccharides / pharmacology
  • Male
  • Middle Aged
  • N-Acetylneuraminic Acid / blood
  • Tumor Necrosis Factor-alpha / biosynthesis*


  • Interleukin-6
  • Lipopolysaccharides
  • Tumor Necrosis Factor-alpha
  • N-Acetylneuraminic Acid