Irisin plasma concentration in PCOS and healthy subjects is related to body fat content and android fat distribution

Irisin (Ir), a recently identified adipo-myokine, cleaved and secreted from the protein FNDC5 in response to physical activity, has been postulated to induce the differentiation of a subset of white adipocytes into brown fat and to mediate the beneficial effects on metabolic homeostasis. Metabolic syndrome (MS), a cluster of factors leading to impaired energy homeostasis, affects a significant proportion of subjects suffering from polycystic ovary syndrome (PCOS). The aim of our study was to investigate the relationship between Ir plasma concentrations and metabolic disturbances. The study group consisted of 179 PCOS patients and a population of 122 healthy controls (both groups aged 25-35 years). A subset of 90 subjects with MS was isolated. A positive association between Ir plasma level and MS in the whole group and in controls was found. In subjects with high adipose body content (>40%), Ir was higher than in lean persons (<30%). Our results showed a significant positive association between Ir concentration and android type of adipose tissue in the whole study group and in the control group. Understanding the role of Ir in increased energy expenditure may lead to the development of new therapeutics for obesity and obesity-related diseases.