Objective: To examine the American–Canadian difference in physical activity and its association with diabetes prevalence. Methods: We used cross-sectional data from nationally representative samples of adults (8688 persons aged ≥ 18 years) participating in the 2004 Joint Canada/U.S. Survey of Health. Using data on up to 22 activities in the past 3 months, we defined 3 physical activity groups (in metabolic equivalents-hours/day) as low (< 1.5), moderate (1.5–2.9), and high (≥ 3.0). We employed logistic regression models in our analyses. Results: Self-reported diabetes prevalence was 7.6% in the U.S. and 5.4% in Canada. The prevalence of low physical activity was considerably higher in the U.S. (70.9%) than in Canada (52.3%), while levels of moderate and high physical activity were higher in Canada (24.6% and 23.1%, respectively) than in the U.S. (14.3% and 14.8%, respectively). Using nationality (Canada as reference) to predict diabetes status, the adjusted odds ratio was 1.48 (95%CI, 1.22–1.79), and became 1.38 (95%CI, 1.15–1.66) when additionally adjusting for physical activity level. We estimate that 20.8% of the U.S.-Canada difference in diabetes prevalence is associated with physical activity. Conclusions: The difference in the prevalence of diabetes between U.S. and Canadian adults may be partially explained by differences in physical activity between the two countries.
Preventive Medicine Vol. 50, Issue 5-6, p. 241-245