According to a Mendelian randomisation study, genetically higher testosterone levels could influence the risk for cancers and metabolic diseases such as polycystic ovary syndrome (PCOS) and type 2 diabetes (T2D).
Researchers at the University of Cambridge and University of Exeter employed genome-wide association studies in 425,097 participants from the UK Biobank to identify 2571 genetic variations linked with differences in testosterone levels and sex hormone-binding globulin. The genetic analyses were further verified in additional studies, including the EPIC-Norfolk study and Twins UK study.
The findings published in the journal Nature Medicine showed that genetically higher testosterone levels in women increased the risks for T2D by 37 per cent and PCOS by 51 per cent. In men, higher testosterone levels lowered the risk for T2D by 14 per cent. Furthermore, genetically higher testosterone levels were associated with increased risks for breast and endometrial cancers in women and prostate cancer in men.
Dr Katherine Ruth, the lead author, said: "Caution is needed in using our results to justify use of testosterone supplements, until we can do similar studies of testosterone with other diseases, especially cardiovascular disease."
