A prospective cohort study of physical activity and body size in relation to prostate cancer risk (United States).
OBJECTIVE
To examine the associations of physical activity and body size with risk of prostate cancer.


METHODS
At baseline in 1988, 8922 men (mean age 67 years) completed a health questionnaire which included information on physical activity, body weight, and waist girth. In a subgroup (74% of men), physical activity data also had been provided in 1962 or 1966 and again in 1977. Additionally, body weight measured at age 18 was available for 92% of men. During follow-up from 1988 through 1993, 439 men developed prostate cancer.


RESULTS
In multivariate analyses that accounted for potential confounders, the RRs (95% CI) for < 4200, 4200-8399, 8400-12,599, and > or = 12,600 kJ/week of physical activity at baseline were 1.00 (referent), 1.13 (0.84-1.52), 0.96 (0.68-1.35), and 1.04 (0.79-1.38), respectively. For body mass indexes (BMI) of < 22.5, 22.5-24.9, 25.0-27.4, and > or = 27.5 kg/m2 at baseline, corresponding results were 1.00 (referent), 1.27 (0.94-1.71), 1.26 (0.92-1.72), and 1.02 (0.68-1.53), respectively. For waist girths of < or = 86.4, 86.5-91.4, 91.5-96.5, and > 96.5 cm, they were 1.00 (referent), 1.30 (0.96-1.76), 1.31 (0.96-1.80), and 1.19 (0.85-1.65), respectively. Combining physical activity measures from the past, or examining vigorous activities only, did not yield any significant associations. BMI at age 18 also was not related to risk.


CONCLUSIONS
These findings do not support a role of physical activity or body weight in prostate cancer etiology.
Department of Epidemiology, Harvard School of Public Health, Boston, MA 02115, USA. i-min.lee@channing.harvard.edu
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Sesso
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Paffenbarger
D017677:Age Distribution; D000368:Aged; D000886:Anthropometry; D001824:Body Constitution; D001835:Body Weight; D015331:Cohort Studies; D016001:Confidence Intervals; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009765:Obesity; D016017:Odds Ratio; D010809:Physical Fitness; D011336:Probability; D011446:Prospective Studies; D011471:Prostatic Neoplasms / Q000175:diagnosis / Q000453:epidemiology* / Q000209:etiology*; D018570:Risk Assessment; D012307:Risk Factors; D014481:United States / Q000453:epidemiology