Diabetes mellitus and the risk of prostate cancer in Italy

Objective: We investigated the relation between diabetes and the risk of prostate cancer, as epidemiological results are controversial. Methods: A hospital-based case-control study was conducted in Italy between 1991 and 2002. Cases were 1294 men, aged <75 years, with incident histologically confirmed prostate cancer, and controls were 1451 men, aged <75 years, admitted to hospital for acute non-neoplastic diseases. Odds ratios (OR) and the corresponding 95% confidence intervals (CI) were estimated using unconditional multiple logistic regression models. Results: No material association between diabetes and prostate cancer was observed, with a multivariate OR of 1.02 (95%CI 0.75-1.40). Prostate cancer was not related to time since diagnosis of diabetes (OR 0.82 and 0.97 for <5 and greater than or equal to15 years since diagnosis respectively). The OR were respectively 1.63 (95%CI 0.70-3.81) and 0.96 (95%CI 0.68-1.34) in men diagnosed with diabetes at age <45 or greater than or equal to45 years. The risk estimates were similar across strata of age at interview, body mass index and, among cases, of Gleason score. Conclusions: This study shows no material association between diabetes and prostate cancer risk. (C) 2004 Elsevier B.V. All rights reserved.