Association between metabolic syndrome, diabetes mellitus and prostate cancer risk

BACKGROUND: The worldwide incidence of diabetes mellitus is rapidly increasing. There is recent interest in the influence ofglucose metabolism on oncogenesis. We investigated the role of diabetes mellitus and the metabolic syndrome (MS) on prostatecancer development.METHODS: This study consisted of 11541 men with coronary heart disease screened to participate in a secondary cardiacprevention trial. MS was defined according to modified NCEP/ATP III criteria. Multivariable regression analysis accounting forcompeting risks was performed using a modified Cox proportional hazard model in order to assess the association betweendiabetes, the MS and the subsequent development of prostate cancer.RESULTS: At baseline, subjects were classified into one of the four groups: (1) 6119 (53%) with neither diabetic mellitus nor MS, (2)3376 (29%) with the MS but without diabetes, (3) 560 (5%) with diabetes mellitus but without MS and (4) 1486 (13%) with bothconditions. Median follow-up was 12.7 years (range 0–15.7 years). During follow-up, 459 new cases of prostate cancer wererecorded. The age-adjusted hazard ratio (HR) for prostate cancer was reduced in diabetic patients compared with those withoutdiabetes, 0.54 and 95% confidence interval of 0.40–0.73. No significant association was noted between the presence of MS andprostate cancer development. On multivariate analysis, diabetes mellitus continued to protect against the development of prostatecancer, this was more pronounced in the absence of MS (HR¼0.43, P¼0.01 for diabetes in the absence of MS; HR¼0.64, P¼0.08in the presence of MS).CONCLUSIONS: The results of this study indicate an inverse association between type 2 diabetes mellitus and prostate cancer risk.Prostate Cancer and Prostatic Disease advance online publication, 12 February 2013; doi:10.1038/pcan.2012.54Keywords: metabolic syndrome; diabetes mellitus; obesityINTRODUCTIONProstate cancer is the most common cancer in men in the westernworld, affecting more than 200000 men a year in the UnitedStates alone.