Endocrine Abstracts

Irisin (Ir), a recently identified adipomyokine, cleaved and secreted to the circulation from the FNDC5 protein in response to physical activity and some environmental conditions has been postulated to induces the differentiation of a subset of white adipocytes into brown fat and mediates the beneficial effects of exercise on metabolic homeostasis. Polycystic ovary syndrome (PCOS) – one of the most frequent endocrinopathies affecting women of child-bearing age is associated with reproductive problems and also metabolic alterations leading to obesity and obesity-related diseases. It is commonly accepted that obesity-associated disorders are related to the type of fat distribution. Individuals with excess of visceral (android) fat but with normal BMI, called MONW (metabolically obese but normal weight), are burdened with obesity-related disease. The aim of our study was to evaluate the relationship between Ir plasma concentrations in PCOS patients and healthy control group in the context of adipose tissue deposits. Our study group consisted of 179 patients with PCOS and a population of 122 healthy control group (both groups aged 25–35 years). We isolated a MONW patients using DEXA criteria of depA (android fat deposit, >30.2% and BMI <25) for the Polish population. In the MONW patients we observed a negative correlation with Ir concentration. We found a statistically significant positive association between Ir concentration and type of adipose tissue deposit – (depA) in the whole study group (P=0.006) and in the control group (P=0.00), while in the PCOS a negative correlation between depA and Ir group (P=0.00) was shown. Our data revealed for the first time that Ir concentration is connected with type of body fat distribution. In this respect PCOS differs from healthy subjects. Moreover we confirmed that an increased Ir secretion in obesity could result from an adaptive response or Ir-resistance.