Abstract

Glucocorticoid Receptor (GR) polymorphisms have been repeatedly associated with obesity and metabolic parameters in man. We have previously shown the genetic influence of a polymorphism in the gene encoding CBG on some obesity parameters in a small female population. In this study we have explored possible genetic associations between obesity and metabolic measures and CBG or GR polymorphisms in a new male population. Two hundred and ninety-five men with body mass index (BMI) ranging from 19 to 55 kg/m² were studied. Serum CBG levels, CBG and GR gene polymorphisms in relation with anthropometric and biochemical parameters were analysed. GR BclI polymorphism was found to influence weight, BMI, waist circumference and glucose levels. CBG polymorphism showed a significant effect for BMI and waist circumference. The frequency of CBG allele 90 was markedly increased among men with morbid obesity compared to the rest of the population (30 versus 18%, p=0.02). The influence of GR BclI polymorphism is replicated in an additional population and CBG polymorphism has a small but significant influence on obesity in men. Further studies are needed to understand the mechanism by which these polymorphisms impact on cortisol and obesity.

Key words: Obesity, genetics, cortisol, transcortin, glucocorticoids.