The Effect of Body Mass Index and Serum Estradiol on Serum Prostatic Specific Antigen in Normal Iraqi Men

Abstract

Background: Prostatic Specific Antigen (PSA) is one of the promising tumor markers of this decade. PSA level correlates positively with age and prostatic volume, and age-adjusted PSA values and the PSA density can be used to more precisely screen for prostatic carcinoma. Aim of the Study: Is to identify the effect of body mass index and serum estradiol level on serum PSA in normal men in Salahaldin province. Subjects & Methods: A cross-sectional controlled study was conducted during the body mass index from the 1st of February 2009 to the end of August 2009 in Salahaldin province. 50 males with BMI ≥ 30 [obese group or group (1)] and 50 males with BMI ≥ 18.5 and < 25 [control group or group (2)] were enrolled in this study. Subjects were collected from Tikrit Teaching Hospital. All subjects were within the same age group between 40-50 years of age. Total serum PSA, serum estradiol, body mass index, and prostatic volume measurement were done for every person in the study. A P value of less than 0.05 was considered significant. Analysis was performed by SPSS software, version 17.0 for windows (SPSS, Chicago, Illinois, USA).Results: The mean age of group (1) was 44 + 2.8 years; while for group (2) was 45.4 + 2 years (P=0.31). Also no significant statistical difference was identified between groups concerning prostatic volume, mean 19.9 + 3.6 ml for group (1) and mean volume was 20.7 + 3.4 ml for group (2) (P=0.48). Mean BMI for group (1) 34.85 + 3.7 kg/m2 (CI 33.8-35.9) was significantly higher than that of group (2), 21.9 + 2.78 kg/m2 (CI 21.4-22.42), P< 0.0001. Mean PSA level for group (2) was significantly higher than that of group (1), 3 + 0.7 ng/ml (CI 2.78-3.2), 2.28 + 0.89 ng/ml (CI 2-2.53) respectively, P< 0.001. Mean estradiol level in group (1) was 91.6 + 20.5 pg/ml (CI 85.8-97.5), whereas it was 57.5 + 22.4 pg/ml (CI 51.1-63.9) for group (2), P< 0.0001. The bivariate correlation showed strong inverse relation between PSA level and BMI (Pearson r=0.635, P<0.01). PSA level had strong inverse relation with estadiol level, (Pearson r=0.705, P<0.001). On applying linear regression model, again inverse relations with strong linear trend between PSA level and both BMI and estradiol level. The increase in BMI and estradiol level was associated with considerable decrease in PSA level. Conclusions: BMI and serum Estradiol had an inverse relationship with serum PSA level. Further studies with larger number of subjects are crucial to asses the specific biological pathway in relation between PSA and BMI.Keywords: Prostatic specific antigen, Body mass index.