Although testosterone supplements are commonly used to treat sexual function, bone health and body composition, it is largely unknown what the long terms effects on disease risk and outcomes is. Researchers from Exeter University set out to see if there is any evidence for long term effects associated with high testosterone levels.
In their study, which involved around 425,000 people, has found evidence that females who have raised levels of the sex hormone have a 37 per cent higher risk of being diagnosed with type 2 diabetes.
Interestingly, the study revealed that for males with genetically high levels of testosterone, the risk of developing type 2 diabetes is 14 per cent lower. Although, findings suggested there was an increased chance of prostate cancer among males with high testosterone levels.
Although testosterone is usually associated with men, being the male sex hormone, women also produce small amounts of it in the ovaries and adrenal glands. This study looked at females who were genetically prone to greater testosterone levels and found, not only a higher type 2 diabetes risk, but also a 51 per cent increased risk of developing polycystic ovary syndrome – a hormonal disorder that affects menstruation.
Genetics specialist Dr Katherine Ruth from Exeter University, who co-lead the study, said their findings have helped to “emphasise the importance of considering men and women separately in studies, as we saw opposite effects for testosterone on diabetes”.
Dr John Perry, who also worked on the trial and is from Cambridge University, added: “In men, testosterone-reducing therapies are widely used to treat prostate cancer, but until now it was uncertain whether lower testosterone levels are also protective against developing prostate cancer.”
The research has been published in the journal Nature Medicine.