Neutral effect of exenatide on serum testosterone in men with type 2 diabetes mellitus: A prospective cohort.

BACKGROUND

Endogenous testosterone increases with weight loss from diet, exercise, and bariatric surgery. However, little is known about testosterone levels after weight loss from medication.

OBJECTIVES

Uncover the effects of Glucagon-Like Peptide-1 receptor agonist (GLP-1 RA) therapy on serum testosterone.

MATERIAL AND METHODS

Prospective cohort study of men starting GLP-1 RA therapy for type 2 diabetes mellitus.

RESULTS

51 men lost 2.27 kg (p = 0.00162) and their HbA1c values improved by 0.7% (p = 0.000503) after 6 months of GLP-1 RA therapy. There was no significant change in testosterone for the group as a whole. However, in subgroup analyses, there was a significant difference in total testosterone change between men starting with baseline total testosterone <320 ng/dL (238.5 ± 56.5 ng/dL to 272.2 ± 82.3 ng/dL) compared to higher values (438 ± 98.2 ng/dL to 412 ± 141.2 ng/dL) (p = 0.0172);free testosterone increased if the baseline total testosterone was <320 ng/dL (55.2 ± 12.8 pg/mL to 57.2 ± 17.6 pg/mL) and decreased if >320 ng/dL (74.7 ± 16.3 pg/mL to 64.2 ± 17.7 pg/mL) (p = 0.00807). Additionally, there were significant differences in testosterone change between men with HbA1c improvements ≥1% (351.6 ± 123.9 ng/dL to 394.4 ± 136.5 ng/dL) compared to men with HbA1c changes <1% (331.8 ± 128.6 ng/dL to 316.1 ± 126.2 ng/dL) (p = 0.0413).

CONCLUSION

GLP-1 RA therapy improves weight and HbA1c without adverse effects on testosterone. Those starting with lower testosterone values or attaining greater improvement in HbA1c may see additional benefits.