Genes that help regulate sex hormones in bloodstream found

Researchers have identified genetic markers that influence a protein involved in regulating estrogen and testosterone levels in the bloodstream.

The results also reveal that some of the genetic markers for this protein are near genes related to liver function, metabolism and type 2 diabetes, demonstrating an important genetic connection between the metabolic and reproductive systems in men and women.

The study led by Boston University School of Medicine  and the University of Exeter in the United Kingdom was done in collaboration with the Framingham Heart Study and investigators from 15 international epidemiologic studies participating in the Cohorts for Heart and Aging Research in Genetic Epidemiology consortium.

Sex hormone-binding globulin (SHBG) is the key protein that carries testosterone and estrogen in the bloodstream in both men and women. As the main carrier of these sex hormones, SHBG helps to regulate their effects in different tissues and organs in the body.

In addition to effects on reproduction in men and women through regulation of sex hormones, SHBG has been linked to many chronic diseases including type 2 diabetes and hormone-sensitive cancers such as breast and prostate.