Retrospective cohort study of androgen deprivation therapy and the risk of diabetes in men with prostate cancer in Lithuania

Objectives To examine the risk of type 2 diabetes in patients with prostate cancer and its association with androgen deprivation therapy (ADT). Design and participants We performed a retrospective cohort study of patients diagnosed with prostate cancer in the Lithuanian male population between 1 January 2003 and 31 December 2012 who were identified through the Lithuanian Cancer registry. All prostate cancer cases were linked to the National Health Insurance Fund database to obtain information regarding the diagnosis of diabetes mellitus and information on prescriptions of antiandrogens and gonadotropin-releasing hormone (GnRH) agonists. Patients with prostate cancer were followed up until the diagnosis of type 2 diabetes, or 31 December 2017, or date of death, whichever came first. Cox proportional hazard models were used to estimate the risk of type 2 diabetes in patients with prostate cancer with or without ADT exposure. Results 27 580 men were diagnosed with prostate cancer, out of whom 14 502 (52.6%) did not receive ADT and 13 078 (47.4%) were treated with ADT. The incidence of type 2 diabetes for all patients with prostate cancer was 7.4/1000 person-years, for men on GnRH agonists 9.0/1000 person-years and 5.8/1000 person-years for men on antiandrogens. There was an increased risk of developing type 2 diabetes comparing ADT users and non-users (HR=1.49, 95% CI 1.34 to 1.66). Conclusion This study showed an increased risk of diabetes in patients with prostate cancer treated with ADT in comparison to ADT-free patient cohort. GnRH agonist users showed higher susceptibility, while the group on antiandrogen monotherapy showed no such increase.