RESUMO
OBJECTIVES: Many factors affecting serum prostate-specific antigen (PSA) levels have been described. The aim of this study was to examine the effect of constipation on serum PSA levels in men. METHODS: Serum total PSA values were measured in 136 constipated patients before and after treatment for constipation. Moreover, they were compared with 45 control patients. RESULTS: Serum total PSA values in the constipated patients before treatment were significantly higher than those in the control group (2.29 ± 1.29 ng/mL vs 1.28 ± 0.86 ng/mL, P < 0.0001). After the treatment of constipation, serum total PSA values in the constipated patients were still higher than those in the control group, but this difference was not statistically significant (P = 0.0871). After the treatment of constipation, prostate biopsy rates were 6.6% and 2.2% in the study and control group, respectively (P = 0.2769). No prostate cancer was found in both groups. CONCLUSIONS: Constipation increases serum PSA levels in men. The presence of constipation must be considered in patients whose PSA is examined, especially in those with PSA levels that are borderline high or in the range of 2-10 ng/mL. Constipated patients must be first treated and then re-evaluated.