Testosterone is a vital male sex hormone and powerful anabolic steroid, providing a variety of several important functions in the human body. In men, low levels of testosterone are linked to a higher risk of developing type 2 diabetes, cardiovascular disease, osteoporosis, sarcopenia, metabolic syndrome, and atherosclerosis. Although researchers know that testosterone levels decrease with age, little is known as to why observed testosterone levels are different from man to man.
An international collaboration of researchers from 10 independent regions combined data of 14,429 Caucasian men and found that genetic variants at the sex hormone-binding globulin (SHBG) gene and on the X chromosome are linked to a higher risk of low testosterone levels. The study was co-led by the University of Gothenburg and the University of Greifswald.
Lead author Prof. Claes Ohlsson from the University of Gothenburg explains:
"This is the first large-scale study to identify specific genes for low serum testosterone concentrations. It is very interesting that the genetic contribution of the identified genetic variants to testosterone concentrations is substantial."
Co-senior author Dr. Robin Haring from the University of Greifswald concludes:
"The reported associations may now be used in order to better understand the functional background of recently identified disease associations related to low testosterone concentrations in men."