Metabolic syndrome-like components and prostate cancer risk: results from the Reduction by Dutasteride of Prostate Cancer Events (REDUCE) study

Objective To evaluate the relationship between number of metabolic syndrome (MetS)-like components and prostate cancer diagnosis in a group of men where nearly all biopsies were taken independent of prostate-specific antigen (PSA) level, thus minimising any confounding from how the various MetS-like components may influence PSA levels. Subjects/Patients and Methods We analysed data from 6426 men in the Reduction by Dutasteride of Prostate Cancer Events (REDUCE) study with at least one on-study biopsy. REDUCE compared dutasteride vs placebo on prostate cancer risk among men with an elevated PSA level and negative pre-study biopsy and included two on-study biopsies regardless of PSA level at 2 and 4 years. Available data for MetS-like components included data on diabetes, hypertension, hypercholesterolaemia, and body mass index. The association between number of these MetS-like components and prostate cancer risk and low-grade (Gleason sum 7) vs no prostate cancer was evaluated using logistic regression. Results In all, 2171 men (34%) had one MetS-like component, 724 (11%) had two, and 163 (3%) had three or four. Men with more MetS-like components had lower PSA levels (P = 0.029). One vs no MetS-like components was protective for overall prostate cancer (P = 0.041) and low-grade prostate cancer (P = 0.010). Two (P = 0.69) or three to four (P = 0.15) MetS-like components were not significantly related to prostate cancer. While one MetS-like component was unrelated to high-grade prostate cancer (P = 0.97), two (P = 0.059) or three to four MetS-like components (P = 0.02) were associated with increased high-grade prostate cancer risk, although only the latter was significant. Conclusion When biopsies are largely PSA level independent, men with an initial elevated PSA level and a previous negative biopsy, and multiple MetS-like components were at an increased risk of high-grade prostate cancer, suggesting the link between MetS-like components and high-grade prostate cancer is unrelated to a lowered PSA level.