Corticosteroid binding globulin gene polymorphism influences cortisol driven fat distribution in obese women.

Hypothalamo-pituitary-adrenal axis has been reported to influence fat mass distribution in obesity. We investigated the hypothesis that corticosteroid-binding globulin (CBG) polymorphism could influence obesity, metabolic, or hypothalamo-pituitary adrenal (HPA) axis activity parameters. In 44 obese pre-menopausal women, a microsatellite located within the CBG gene was analyzed, providing three genotypes: 86/86 (n = 29), 86/90 (n = 14), and 90/90 (n = 1). No significant difference was found for obesity, metabolic, and HPA axis activity parameters between the genotypes 86/86 and 86/90. Looking for differences in correlations between HPA axis activity parameters and obesity or metabolic parameters between the two genotypes, genotype 86/90 showed a strong correlation between salivary cortisol after dexamethasone (0.25 mg) suppression test and waist-to-hip ratio (r = -0.84, p = 0.0007), whereas this correlation was weaker for genotype 86/86 (r = -0.34, p = 0.09). These data were completed with an analysis of the BclI polymorphism of the glucocorticoid receptor (GR) gene. There was an association between this GR polymorphism and both awakening salivary cortisol and postdexamethasone salivary cortisol but no association for obesity or metabolic parameters. We concluded that CBG gene polymorphisms might modulate the influence of the HPA axis on the fat mass distribution in this population.