Modulation of SHBG binding to testosterone and estradiol by sex and morbid obesity.

Objective: Sex hormone-binding globulin (SHBG) binds and transports testosterone and estradiol in plasma. The possibility that SHBG is a mixture of transporting proteins has been postulated. We analyzed in parallel the effects of obesity status on the levels and binding capacity of circulating SHBG and their relationship with testosterone and estradiol.