Abstract

Objective: The purpose of this study is to examine whether long term testosterone replacement therapy (TRT) improves blood glucose control in aged men with hypogonadism and diabetes mellitus.
Research design and methods: This is a retrospective and observational study using data from patients’ Electronic Medical Record (EMR) at Hines Veteran Administration Hospital for 5 years, 2002-2007. The data were obtained from 129 out of 642 individuals with type 2 DM (T2DM) and hypogonadism, either receiving testosterone replacement therapy (TRT group) or not (control group) based on patient’s personal decision.
Results: The overall mean HbA1c in the TRT group was lower by 0.25% compared to those of control group, 95% CI=0.016-0.49, p=0.037. After adjusting data by age, BMI, hemoglobin, and antidiabetic medications, HbA1c in TRT group decreased by 0.38%, CI=0.10-0.66, p<0.009. In a subgroup analysis, for the first time, we found that the mean HbA1c in TRT group decreased in those who received lower doses of antidiabetic, compared to those on control group: by 0.61%, CI=0.23-0.99, p=0.002 (oral agents) and by 0.27%, CI=0.011-0.52, p=0.041 (insulin). However, there was no association between TRT and glucose control in those patients who were on larger doses of antidiabetic. All the data were adjusted for age, BMI, and hemoglobin level.
Conclusion: TRT was associated with a modest but significant improvement of HbA1C in aged hypogonadal men with T2DM. Interestingly, the improvement of HbA1C was more significant in individuals whose blood glucose was controlled with less medications and no worsening of HbA1c was noted in TRT group who were treated with large doses of antidiabetic.

Keywords: Type 2 Diabetes mellitus; Glycemic control; Testosterone replacement therapy