Urology, University of Michigan, 1011 Michigan House, 2301 Commonwealth Blvd., Ann Arbor, MI, 48105-2967, United States.
To investigate the association of BMI and BMI change with change in PSA level andto assess the possible roles of PSA hemodilution and prostate volume in explaining the obesityand PSA association.
In 1990, a randomly selected cohort of Caucasian men, ages 40-79, from OlmstedCounty, MN completed questionnaires ascertaining demographic characteristics, currentmedical conditions and medications biennially, with a subset undergoing blood draws andclinical exams. Linear mixed models were used to predict annual changes and intercepts ofindividual changes in BMI, PSA, prostate volume, plasma volume, and PSA mass, adjusting forage in 545 men with at least two serial PSA, BMI and prostate volume measurements.
Baseline BMI was inversely associated with the annual percent change in PSA,adjusting for age, baseline PSA, and prostate volume and the rates of change in BMI andprostate volume (β=-0.003, 95% Confidence Interval (CI): -0.006, -0.0003). Baseline obesitywas positively associated with mean baseline levels and the rate of change in prostate volume(p=0.002) and plasma volume (both p < 0.001) but was not associated with either the meanbaseline values or the rate of change in PSA mass.
Baseline obesity was associated with baseline PSA and prostate volume and with the rate of change in PSA over 15 years of follow-up.
The inverse association of obesity with prostate-cancer diagnosis may be at leastpartly due to detection bias, which is due to larger prostate volumes and PSA hemodilution inobese men.
Wallner LP, Morgenstern H, McGree ME, Jacobson DJ, St Sauver JL, Jacobsen SJ, Sarma A. Are you the author?
Reference: Cancer Epidemiol Biomarkers Prev. 2011 Jan 17. Epub ahead of print.