Cross-national comparison of the association between race and obesity prevalence in older adults

Background: Obesity has become an epidemic in many countries around the world. In the US, obesity prevalence is much higher among African Americans than Whites, particularly women. Reasons for this disparity are not well understood, and it is unknown whether it persists in other countries. Sample: 4599 individuals 60+ from Barbados, Brazil, and Cuba sites of the 1999-2000 Survey on Health, Well-being, and Aging in Latin America and the Caribbean and 3443 from US-based 1999-2004 National Health and Nutrition Examination Survey. Methods: Height and weight were measured; obesity was defined as having a body mass index of 30 kg/m2 or more. Gender-stratified log-linear regression accounting for complex sampling designs was used to estimate the association between race and obesity. Interaction terms were included to determine whether the association between race and obesity varied by country. Results: Obesity prevalence was higher among females across all the countries, and among those living in the US than the other sites. There was a significant age-adjusted association between race and obesity among women (PR: 1.19, 95% CI: 1.04, 1.36) but not men (PR: 0.97, 95% CI: 0.78, 1.21) in country-pooled analyses. However, there were significant interactions between race and country among women, and the direction suggested that the Black-White disparity was lower in each of the other countries versus the US. Furthermore, the association between race and obesity was stronger in the US (PR: 1.55, 95% CI: 1.30, 1.85). There were no significant interactions among men. Conclusions: These findings suggest that the Black-White disparity in obesity among women is weaker in countries outside the US, providing further evidence that there are social-environmental factors contributing to the unequal burden of obesity in the US. Future work will assess potential country-level and individual-level contributors to the variations seen in this disparity.