Physical activity and risk of B-cell non-Hodgkin's lymphoma among Los Angeles women

2012-01-27Study Aim: There have been few studies focusing on the association between physical activity and risk of B-cell non-Hodgkin’s lymphomas (NHL) and their results are inconsistent. This study is designed to assess this association among women in Los Angeles County. Methods: An individually matched population-based case-control design was applied in this study. 990 case participants and their 1:1 matched controls were recruited in total. Exposure information was collected through in-person interviews finished by all the cases as well as the controls. Multivariate conditional logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs), which measure the relationship between physical activity and risk of B-cell NHL. Results: Physical activity does not protect against developing B-cell NHL among women in Los Angeles County. The same results were found for the association between physical activity and B-cell NHL risk by race/ethnicity, age at diagnosis, body mass index (BMI) and B-cell NHL subtype. Compared to the inactive women, those who were at the highest physical activity level had 30% lower B-cell NHL risk (OR=0.70, 95% CI=0.52-0.94). However, no dose response was observed with increasing physical activity level (p value for the trend test=0.92). Conclusion: Physical activity was not associated with B-cell NHL risk. Future studies with larger sample sizes were needed to confirm our results