The investigators working hypothesis is that RNase L and RLI contribute to chronic inflammation regulation and to insulin response through TLR 4 pathway regulation in obesity. The investigators main purpose is to compare innate immunity activation pathway between insulin sensitive, insulin resistant obese patients and control patients. Insulin sensitive and insulin resistant obese patients will be distinguish thanks to the HOMA ir index. The investigators second objectives are to evaluate if the degree of inflammation in adipose tissue and squeletal muscle is correlated to insulin sensitivity measured by hyperinsulinemic euglycemic clamp and to characterise inflammatory pathway and regulation pathway. A special focus will be given to the leukotrienes and their potential role in insulin resistance pathogenesis. The investigators will have two approaches:- characterisation of subjects with normal weight, of obese insulin sensitive and obese insulin resistant through a metabolic evaluation, an inflammatory characterisation and a measure of insulin sensitivity at the systemic level, in adipose tissue and in squeletal muscle.- an in vitron approach with human myoblast and adipocytes culture, extracted from the investigators patients: characterisation of inflammation, innate immunity.