Male hypogonadism is associated with an increased risk of prediabetes and type 2 diabetes. Testosterone replacement increases muscle mass and is associated with improved insulin sensitivity, and there are data to suggest that progression from prediabetes to diabetes is slower in men with hypogonadism who are treated with testosterone compared with those who are untreated.

As part of a prespecified nested study, investigators in the randomised TRAVERSE (Testosterone Replacement Therapy for Assessment of Long-Term Vascular Events and Efficacy Response in Hypogonadal Men) Trial compared markers of glycaemic control in hypogonadal men receiving testosterone gel (1.62%) and placebo. There was no significant difference between testosterone and placebo groups with respect to relative risk of progression from prediabetes to diabetes. For those known to have diabetes at baseline, there was no significant difference in risk of glycaemic remission between the two groups. Changes in glycated haemoglobin (HbA1c) and fasting glucose were not significantly different between the testosterone and placebo groups.

In this study, there was no evidence that, in men with prediabetes or diabetes, testosterone treatment was associated with any improvement in markers of glycaemic control, or in rate of progression from prediabetes to diabetes. Men in this study had mild hypogonadism, which could explain this finding; additionally, whilst fasting glucose and HbA1c were reviewed, other more sensitive markers, such as oral glucose tolerance test, might have shown different findings.

Read the full article in JAMA Internal Medicine 184 353–362 https://doi.org/10.1001/jamainternmed.2023.7862