Body mass index, prostate-specific antigen, and digital rectal examination findings among participants in a prostate cancer screening clinic.

OBJECTIVES

Prior studies suggested obese men have lower prostate-specific antigen (PSA) values. However, the association between body mass index (BMI) and digital rectal examination (DRE) findings and the association between weight at age 18 and adult PSA or DRE findings have not been examined. We sought to study the associations among BMI and weight at age 18 and adult PSA and DRE findings.

METHODS

We analyzed data from 535 participants in a free prostate cancer-screening program in North Carolina held in September 2006. The associations among BMI and weight at age 18 and abnormal DRE and PSA levels were determined using multivariate logistic and linear regression models, respectively.

RESULTS

A total of 391 men (73%) were overweight or obese, of whom 144 (27%) were obese. Mean +/- standard deviation and median age were 61.4 +/- 10.5 and 61 years, respectively; and 294 men (55%) were black, 219 (41%) white, and 22 (4%) neither black nor white. On multivariate analysis, higher BMI was significantly associated with lower PSA values (P = 0.03) but was not significantly associated with DRE findings. Weight at age 18 was not significantly related to adult PSA levels or DRE findings.

CONCLUSIONS

In a multiethnic cohort of participants in a prostate cancer-screening clinic, obesity was associated with decreased PSA levels. We found no significant associations among BMI and DRE findings or weight at age 18 and adult PSA levels or DRE findings. The current data suggest that the PSA cut-points used to recommend biopsy need to be adjusted for the degree of obesity.