A study done by Duke University Medical Center researchers found that overweight or obese men had lower concentrations of prostate-specific antigen (PSA) in their blood than normal weight men. PSA is a protein released into the blood by the prostate gland, and is elevated in the presence of cancer.
This study mirrors an earlier study done by the group and brings to light the need to reconsider PSA threshold values for heavier patients and also the need to encourage patients to lose weight.
For this study, researchers looked at PSA scores among 535 men who took part in a free prostate cancer-screening program. Seventy-three percent of the group was overweight or obese. The results indicated that mildly obese men’s PSA scores were fourteen percent lower than normal weight men, and moderately and severely obese men had 29 percent lower PSA values.
Doctors theorize that overweight and obese men have lower PSA scores because their bodies have a greater volume of blood. Larger blood volumes dilute the amount of PSA in the bloodstream, making the concentration of PSA lower.
The latest results appear online in the Feb. 9, 2008 issue of the journal Urology. The study was funded by the United States Department of Defense.

Source: Duke University Medical Center