Serum cortisol and sex hormone binding globulin (SHBG) levels, body fat distribution and the role of genetic factors in obese females.

Abstract

Fasting plasma levels of both cortisol and sex hormone binding globulin (SHBG) in obese women were significantly inversely related to anthropometric characteristics of body fat distribution. It means that a central accumulation of body fat might be partly mediated by cortisol and SHBG levels. Significant within-pair resemblance observed in plasma cortisol level in obese female monozygotic twins suggests an important role of genetic factors in determination of cortisol secretion. However, no within-pair similarities revealed in plasma SHBG concentrations favour a major role of environmental factors in the regulation of plasma SHBG level. On the other hand the twin study supported the role of genetic determinants in changes of both cortisol and SHBG levels in response to energy deficit induced by very low calorie diet (VLCD). The mechanisms controlling baseline levels of cortisol and SHBG apparently differ from those controlling their responses to energy restriction.