Association between serum prostate-specific antigen level and diabetes, obesity, hypertension, and the laboratory parameters related to glucose tolerance, hepatic function, and lipid profile: implications for modification of prostate-specific antigen threshold.

Background: Previous studies indicated inverse relationships between body mass index (BMI), diabetes and prostate-specific antigen (PSA) concentration besides an established positive relationship between age and PSA. Other causal relationships between clinical parameters including hypertension, hepatic function, tests, lipid profile and PSA were also suggested. Thus, we incorporated these parameters all together into the analysis to identify possible determinants of PSA concentration to improve the accuracy of PSA tests.

Methods: Associations between PSA and the above-mentioned clinical parameters were examined among 14,486 men who visited our hospital for a routine health checkup, using linear regression analyses.

Results: Total of 1403 (9.7%) and 784 (5.4%) men were classified as diabetes and obesity, respectively. After adjusting age, significant PSA reductions were found in diabetic men, especially for men taking antidiabetics. Such association was seen when the diabetic status was represented by hemoglobin A1c (HbA1c) and fasting blood sugar (FBS) levels. That is, PSA levels were significantly reduced in men with higher HbA1c and FBS levels. Obesity was also associated with a reduction in PSA levels. Moreover, PSA levels were significantly decreased with increased ALT levels.

Conclusions: PSA test results should be carefully interpreted especially for men with diabetes and obesity, in whom a substantial reduction in PSA concentration is likely to occur.