The roles of IL-6, IL-10, and IL-1RA in obesity and insulin resistance in African-Americans

J Clin Endocrinol Metab. 2011 Dec;96(12):E2018-22. doi: 10.1210/jc.2011-1497. Epub 2011 Sep 28.

Abstract

Objective: The aim of the study was to investigate the associations between IL-1 receptor antagonist (IL-1RA), IL-6, IL-10, measures of obesity, and insulin resistance in African-Americans.

Research design and methods: Nondiabetic participants (n = 1025) of the Howard University Family Study were investigated for associations between serum IL (IL-1RA, IL-6, IL-10), measures of obesity, and insulin resistance, with adjustment for age and sex. Measures of obesity included body mass index, waist circumference, hip circumference, waist-to-hip ratio, and percent fat mass. Insulin resistance was assessed using the homeostasis model assessment of insulin resistance (HOMA-IR). Data were analyzed with R statistical software using linear regression and likelihood ratio tests.

Results: IL-1RA and IL-6 were associated with measures of obesity and insulin resistance, explaining 4-12.7% of the variance observed (P values < 0.001). IL-1RA was bimodally distributed and therefore was analyzed based on grouping those with low vs. high IL-1RA levels. High IL-1RA explained up to 20 and 12% of the variance in measures of obesity and HOMA-IR, respectively. Among the IL, only high IL-1RA improved the fit of models regressing HOMA-IR on measures of obesity. In contrast, all measures of obesity improved the fit of models regressing HOMA-IR on IL. IL-10 was not associated with obesity measures or HOMA-IR.

Conclusions: High IL-1RA levels and obesity measures are associated with HOMA-IR in this population-based sample of African-Americans. The results suggest that obesity and increased levels of IL-1RA both contribute to the development of insulin resistance.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, N.I.H., Intramural

MeSH terms

  • Adult
  • African Americans*
  • Female
  • Humans
  • Insulin Resistance*
  • Interleukin 1 Receptor Antagonist Protein / blood*
  • Interleukin-10 / blood*
  • Interleukin-6 / blood*
  • Male
  • Middle Aged
  • Obesity / immunology*

Substances

  • Interleukin 1 Receptor Antagonist Protein
  • Interleukin-6
  • Interleukin-10