American Journal of Epidemiology Advance Access originally published online on October 21, 2008
American Journal of Epidemiology 2008 168(12):1416-1424; doi:10.1093/aje/kwn272
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ORIGINAL CONTRIBUTIONS |
Serum Steroid and Sex Hormone-Binding Globulin Concentrations and the Risk of Incident Benign Prostatic Hyperplasia: Results From the Prostate Cancer Prevention Trial
Correspondence to Dr. Alan R. Kristal, Cancer Prevention Program, Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue North, M4-B402, P.O. Box 19024, Seattle, WA 98109-1024 (e-mail: akristal{at}fhcrc.org).
Received for publication February 15, 2008. Accepted for publication July 29, 2008.
The authors conducted a nested case-control study of serum steroid concentrations and risk of benign prostatic hyperplasia (BPH), using data from the placebo arm of the Prostate Cancer Prevention Trial (1993–2003). Incident BPH over 7 years (n = 708) was defined as receipt of treatment, a report of 2 International Prostate Symptom Score (IPSS) values greater than 14, or 2 increases of 5 or more from baseline IPSS values with at least 1 value greater than or equal to 12. Controls (n = 709) were selected from men who reported no BPH treatment or any IPSS greater than 7. Baseline serum was analyzed for testosterone, estradiol, estrone, 5
-androstane-3
, 17β-diol-glucuronide, and sex hormone-binding globulin. Covariate-adjusted odds ratios contrasting the highest quartiles with the lowest quartiles of testosterone, estradiol, and testosterone:17β-diol-glucuronide ratio were 0.64 (95% confidence interval (CI): 0.43, 0.95; Ptrend = 0.04), 0.72 (95% CI: 0.53, 0.98; Ptrend = 0.09), and 0.64 (95% CI: 0.46, 0.89; Ptrend = 0.004), respectively. Findings did not differ by age, body mass index, time to BPH endpoint, or type of BPH endpoint. High testosterone levels, estradiol levels, and testosterone:17β-diol-glucuronide ratio are associated with reduced BPH risk, which may reflect decreased activity of 5-
-reductase. Genetic or environmental factors that affect the activity of 5-
-reductase may be important in the development of symptomatic BPH.
gonadal steroid hormones; prostatic hyperplasia
Abbreviations: BPH, benign prostatic hyperplasia; CI, confidence interval; IPSS, International Prostate Symptom Score; OR, odds ratio; SHBG, sex hormone-binding globulin