Prostate specific antigen levels and inflammatory markers in older men from the National Health and Nutrition Survey (2001-2002) Free

B126

Background: Prostate-specific antigen (PSA) levels may vary with inflammation status. However, there is not enough scientific evidence of this relationship. Therefore, we examined the association utilizing data from the 2001-2002 National Health and Nutrition Examination Survey, a nationally representative cross-sectional sample of non-institutionlized civilian US population.
 >Method: Men 40+ years were eligible from this cross-sectional survey. Men with recent digital examination, prostate biopsy or cytoscopy, or with a history of prostate cancer or inflammation of the prostate were excluded from the analyses (n=410). Men with missing serum markers of inflammation were excluded (n=8), leaving 1,300 men in the final analysis dataset. Using Proc Surveyreg, SAS v9.1, multiple regression models were fit to evaluate the influence of three biomarkers of systemic inflammation: fibrinogen, C-reactive protein (CRP) and white blood cell (WBC) count, on PSA levels. NHANES 2001-2002 sample weights were applied in all the analyses to account for individual selection probabilities, non-response and post-stratification that resulted from the complex survey design.
 >Results: After adjusting for age, race, and waist circumference, a marker of obesity, the overall geometric mean PSA was 0.9 ng/mL (CI:0.9-1.0) among men within the lowest quartile of fibrinogen versus 1.3(CI:1.1-1.5) (40% higher), within the highest quartile of fibrinogen (p-trend <0.001). In the overall population, geometric mean PSA levels were about 30% higher in the highest compared with the lowest quartile of CRP (1.2 ng/mL (CI:1.1-1.3) versus 0.9(CI:0.8-1.1; p-trend=0.006)), and 20% higher in the highest compared with the lowest quartile of WBC count (1.1ng/mL (CI:1.0-1.2) versus 0.9(CI:0.8-1.0; p-trend=0.47). Results were in the same direction for black and white men after adjustment for age and waist circumference.
 >Conclusions: PSA level is positively associated with biomarkers of systemic inflammation. The biological mechanisms are unclear. It remains to be determined whether systemic inflammation needs to be taken into consideration while interpreting PSA values. Additional studies are needed to understand the clinical relevance of these associations.