Physical activity, sedentary behavior, and endometrial cancer risk in the NIH‐AARP Diet and Health Study

• Published in: International journal of cancer 2009-05, Vol.124 (9), p.2139-2147
• Main Authors: Gierach, Gretchen L., Chang, Shih‐Chen, Brinton, Louise A., Lacey, James V., Hollenbeck, Albert R., Schatzkin, Arthur, Leitzmann, Michael F.
• Format: Article
• Language: English
• Subjects: Aged; Biological and medical sciences; Body Mass Index; Cohort Studies; Diet; Endometrial Neoplasms - epidemiology; Endometrial Neoplasms - etiology; Exercise; exercise/physiology; Female; Female genital diseases; Follow-Up Studies; Gynecology. Andrology. Obstetrics; health behavior; Humans; Incidence; Medical sciences; Middle Aged; Motor Activity; National Institutes of Health (U.S.); Obesity - complications; Postmenopause; prospective studies; recreation/physiology; Risk Assessment; Surveys and Questionnaires; Tumors; United States - epidemiology; Women's Health
• ISSN: 0020-7136; 1097-0215
• DOI: 10.1002/ijc.24059

Consistent with a strong hormonal etiology, endometrial cancer is thought to be influenced by both obesity and physical activity. Although obesity has been consistently related to risk, associations with physical activity have been inconclusive. We examined relationships of activity patterns with endometrial cancer incidence in the NIH‐AARP Diet and Health Study cohort, which included 109,621 women, ages 50–71, without cancer history, who in 1995–1996 completed a mailed baseline questionnaire capturing daily routine and vigorous (defined as any period of ≥20 min of activity at work or home causing increases in breathing, heart rate, or sweating) physical activity. A second questionnaire, completed by 70,351 women, in 1996–1997 collected additional physical activity information. State cancer registry linkage identified 1,052 primary incident endometrial cancers from baseline through December 31, 2003. In multivariate proportional hazards models, vigorous activity was inversely associated with endometrial cancer in a dose‐response manner (p for trend = 0.02) (relative risk (RR) for ≥5 times/week vs. never/rarely = 0.77, 95% confidence interval (CI): 0.63–0.95); this association was more pronounced among overweight and obese women (body mass index ≥25; RR = 0.61, 95% CI: 0.47–0.79) than among lean women (body mass index