Influence of Opioid Consumption on Serum Prostate-specific Antigen Levels in Men Without Clinical Evidence of Prostate Cancer

Objective To determine the effect of opioid consumption on the serum prostate-specific antigen (PSA) level. Methods From April 2009 to December 2011, 56 opioid users and 82 age-matched controls participated in the present study. The exclusion criteria were prostate cancer or other malignancies, serum PSA level ≥4 ng/dL, abnormal digital rectal examination findings, previous prostate surgery, pelvic radiotherapy, bladder stone, urinary tract infection, recent prostatic manipulation, and a history of taking drugs that alter the serum PSA level. The prostate volume and PSA, serum testosterone, and luteinizing and follicle-stimulating hormone levels were measured in the eligible participants and compared between the opioid users and control subjects. The study was conducted in accordance with the Declaration of Helsinki, and the institutional review board approved the study. Results The serum PSA level was significantly lower in opioid users compared with that in the control subjects (0.82 ± 0.77 vs 1.95 ± 1.00, P < .001). The testosterone level was also lower in the opioid users (339.08 ± 142.49 vs 396.71 ± 133.64, P = .008). The difference between the PSA levels remained significant when a comparison was performed between the eugonadal opioid users and eugonadal control subjects. Moreover, the effect of opioid consumption on the PSA level persisted on multivariate analysis, controlling for serum testosterone level. Conclusion Opium consumption was associated with significant decline in the serum PSA level and warrants adjustment in the PSA cutpoints at which biopsy is recommended. Opioid-induced hypogonadism does not seem to account for the PSA decline, and additional studies are required to determine the involved mechanisms.