Aims/introduction: There is still no obvious evidence proving that androgen deprivation therapy (ADT) would increase the risk of diabetes. To determine if ADT is associated with diabetes in men with prostate cancer, we carried out the present study.

Materials and methods: We systematically searched Medline, Embase and the Cochrane Library Central Register through 2014. Studies comparing ADT vs control aimed at treating prostate cancer reporting diabetes as outcome were included. Data were extracted independently by two reviewers. This meta-analysis was reported based on the Preferred Reporting Items for Systematic reviews and Meta-Analyses checklist. Observational studies were evaluated through the Meta-analysis Of Observational Studies in Epidemiology checklist.

Results: Eight studies were identified with 65,695 ADT users and 91,893 non-ADT users. The pooled incidence of diabetes was 39% higher in ADT groups. A significant association was observed in the overall analysis (risk ratio [RR] 1.39, 95% confidence interval [CI] 1.27-1.53; P < 0.001). In subgroup analyses, diabetes was found to be significantly associated with gonadotropin-releasing hormone (GnRH) alone (RR 1.45, 95% CI 1.36-1.54; P < 0.001), GnRH plus oral antiandrogen (RR 1.40, 95% CI 1.01-1.93; P = 0.04) and orchiectomy (RR 1.34, 95% CI 1.20-1.50; P < 0.001), but not with antiandrogen alone (RR 1.33, 95% CI 0.75-2.36; P = 0.33). Diabetes was strongly related to long duration of ADT (RR 1.43, 95% CI 1.22-1.68; P < 0.001), and was slightly associated with short duration of ADT (RR 1.29, 95% CI 1.12-1.49; P = 0.0004).

Conclusions: ADT, especially long duration (>6 months) of this treatment, GnRH alone, GnRH plus antiandrogen and orchiectomy can increase the incidence of diabetes.