Long-term testosterone therapy could help men with type 2 diabetes and low testosterone levels lose weight and even put type 2 diabetes into remission, research suggests.
A German study has been looking at the effects of testosterone, a male hormone produced primarily in the testicles, on health across 10 years.
A group of 311 men with low testosterone (also known as hypogonadism) and type 2 diabetes took part in the study. They were split into two groups, one of which was given testosterone therapy while the other acted as a control group.
Testosterone therapy (TTh) involved receiving injections every 12 weeks of a drug called testosterone undecanoate, which is used to mainly treat low testosterone levels in men.
All those who took part were then revisited several times where they had blood samples taken, their weight recorded and their HbA1c levels were also noted.
By the end of the decade-long study, average fasting blood glucose levels had decreased in those who had been given the treatment, but they had risen in the group without treatment.
Dr Farid Saad, from Bayer AG in Berlin, who led the study, said: “Long-term testosterone therapy can support diabetes treatment in hypogonadal men with T2D.
“Its use improved the control of blood glucose, while it deteriorated in patients who had opted not to receive TTh. There were also significant reductions in both weight and waist size in the T-group, which we suggest could have contributed to the observed effects.
“The results, especially in the diabetic subgroup, are becoming increasingly interesting as we had the first patients who went into remission, some after as many of 10 years of testosterone treatment.”
The average HbA1c levels also fell in the testosterone therapy from 75 mmol/mol (9.0%) to 31 mmol/mol (5.9%) but rose in the other group.
There were 61 people in the treatment group who took insulin and at the end of the trial; their dose had reduced from 34 to 19.9 units a day. Those who did not take the testosterone saw their insulin usage go up from 30.7 to 42.2 units daily.
Weight loss was also significant in the treatment group, with the average loss going from 113.4 to 90.7kg, although weight remained stable in those who did not receive the testosterone therapy.
Although there appears to be only positive benefits from the testosterone therapy, there is a concern that administering it to middle-aged and elderly men could increase the risk of prostate cancer, although there is no substantial evidence as yet to support this.
Dr Saad said: “The other concern is an increase in haemoglobin and haematocrit which, however, may be a beneficial effect of testosterone rather than a side effect.”
The findings have been revealed at this year’s annual meeting of the European Association for the Study of Diabetes (EASD).