The authors declare that they have no competing interests.
AB-L: Preparation and critical revision of the manuscript, design of the analytical strategy, data analysis, interpretation of the data. AS: Interpretation of the data and critical revision of the manuscript. P-IK: Contribution to the data acquisition, interpretation of the data and critical revision of the manuscript. AA: Interpretation of the data and critical revision of the manuscript. FS: Contribution to the data acquisition and critical revision of the manuscript. M-E.P: Conception of the overall PROtEuS study, interpretation of the data and critical revision of the manuscript. All authors read and approved the final manuscript.
The role of metabolic syndrome (MetS) in prostate cancer risk is still debated. We investigated it in a large population-based case–control study.
Cases were 1937 men with incident prostate cancer, aged ≤75 years, diagnosed across French hospitals in the Montreal area between 2005 and 2009. Concurrently, 1995 population controls from the same residential area and age distribution were randomly selected from electoral list of French-speaking men. Detailed lifestyle and medical histories, and anthropometric measures, were collected during in-person interviews. Prevalence of MetS components (type 2 diabetes, high blood pressure, dyslipidemia and abdominal obesity) was estimated at 2 years before diagnosis for cases/ interview for controls, and at ages 20, 40, 50 and 60. Logistic regression was used to estimate odds ratios (OR) and 95 % confidence intervals for the association between MetS and prostate cancer risk.
A history of MetS (≥3 components vs <3) was associated with a reduced risk of prostate cancer (OR = 0.70 [0.60, 0.82]) after considering potential confounders. The negative association was particularly pronounced with a young age (≤40 years) at MetS onset (OR = 0.38 [0.16-0.89]), did not vary according to prostate cancer aggressiveness, and was only partly explained by the presence of type 2 diabetes. A risk decrease was observed with the number of MetS components, suggesting a synergistic interaction of the components.
The observed negative association, consistent with results from other North American populations undergoing regular prostate cancer screening, underlines the importance of considering PSA-testing when studying the MetS-prostate cancer association.
Findings from this study are consistent with an inverse association between MetS and prostate cancer risk.