[Insulin resistance and adipose tissue gene expression in humans]

Obesity is a risk factor for type 2 diabetes and cardiovascular diseases. The hypothesis that cytokines could play a role in the pathophysiology of obesity and insulin resistance is suggested in the last few years. We showed a positive correlation between circulating interleukin (IL-6) levels and obesity and insulin resistance suggesting that IL-6 could be involved in insulin resistance in humans. We showed a decrease of both circulating and adipose tissue IL-6 levels in non-diabetic obese subjects after a very low calorie diet program inducing weight loss. This suggests that adipose tissue could be involved in the regulation of circulating IL-6 levels in these subjects. Adipose tissue is also involved in lipodystrophies particularly in HIV patients on antiviral therapy. We showed an alteration of the SREBP-1 transcription step in subcutaneous abdominal adipose tissue from HIV patients. We found an inverse correlation between circulating adiponectin levels and both insulin resistance and cardiovascular risk factors such as CRP levels and apolipoprotein B/A1 ratio. These findings suggest that adipose tissue is involved in insulin resistance in humans particularly via adipocytokine secretion.