Serum prostate-specific antigen is better correlated to body surface area than body mass index in a population of healthy Korean men.

It has been suggested that the larger vascular volume among obese men causes a dilution effect, decreasing the concentration of serum prostate-specific antigen (PSA). However, plasma volume is proportional to body surface area (BSA) rather than to body mass index (BMI). We determined whether serum PSA level is better correlated to BSA than BMI in a population of ostensibly healthy Korean men. Data from 2604 men who visited our health promotion center were evaluated. All men underwent anthropometric measurements, digital rectal examination, serum PSA determination, and transrectal ultrasound examination. The correlation between serum PSA and other parameters was statistically analyzed. The mean age was 49.9 years and the mean serum PSA level was 1.14 ng/mL. The multivariate analysis revealed that the serum PSA was positively correlated with age, prostate volume, and negatively correlated with BSA only and not with BMI. In addition, BSA, rather than BMI, was the significant factor in predicting the prostate volume. Our results suggest that men with larger BSA (rather than BMI), have larger prostate volumes, and lower serum PSA.