American Journal of Epidemiology Advance Access originally published online on October 12, 2009
American Journal of Epidemiology 2009 170(10):1231-1240; doi:10.1093/aje/kwp268
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ORIGINAL CONTRIBUTIONS |
Body Size, Recreational Physical Activity, and B-Cell Non-Hodgkin Lymphoma Risk Among Women in the California Teachers Study
* Correspondence to Dr. Yani Lu, Division of Cancer Etiology, Department of Population Sciences, City of Hope National Medical Center, 1500 East Duarte Road, Duarte, CA 91010 (e-mail: yalu{at}coh.org).
Received for publication July 2, 2009. Accepted for publication August 5, 2009.
Nutritional status and physical activity are known to alter immune function, which may be relevant to lymphomagenesis. The authors examined body size measurements and recreational physical activity in relation to risk of B-cell non-Hodgkin lymphoma (NHL) in the prospective California Teachers Study. Between 1995 and 2007, 574 women were diagnosed with incident B-cell NHL among 121,216 eligible women aged 22–84 years at cohort entry. Multivariable-adjusted relative risks and 95% confidence intervals were estimated by fitting Cox proportional hazards models for all B-cell NHL combined and for the 3 most common subtypes: diffuse large B-cell lymphoma, follicular lymphoma, and B-cell chronic lymphocytic leukemia/small lymphocytic lymphoma. Height was positively associated with risk of all B-cell NHLs (for >1.70 vs. 1.61–1.65 m, relative risk = 1.50, 95% confidence interval: 1.16, 1.96) and chronic lymphocytic leukemia/small lymphocytic lymphoma (relative risk = 1.93, 95% confidence interval: 1.09, 3.41). Weight and body mass index at age 18 years were positive predictors of B-cell NHL risk overall. These findings indicate that greater height, which may reflect genetics, early life immune function, infectious exposures, nutrition, or growth hormone levels, may play a role in NHL etiology. Adiposity at age 18 years may be more relevant to NHL etiology than that in later life.
body mass index; body size; cohort studies; exercise; hip; lymphoma, non-Hodgkin; waist-hip ratio
Abbreviations: CLL, B-cell chronic lymphocytic leukemia; ICD-O-3, International Classification of Diseases for Oncology, Third Edition; NHL, non-Hodgkin lymphoma; SLL, small lymphocytic lymphoma