Abstract 3599: Long-Term Relation of Physical Activity with Maintenance of a Stable Body Mass Index over 20 years: the CARDIA Study
Background: Maintaining a stable weight from young adulthood into middle age is associated with markedly fewer adverse changes in cardiovascular disease risk factors. Although physical activity is recommended to maintain weight, the relationship between physical activity and weight stability in young adults is not clear.
Methods: Black and white adults ages 18 –30 in the CARDIA Study, an NHLBI sponsored multi-center longitudinal study, had anthropometric measures taken and answered questions regarding physical activity using an interviewer-based questionnaire at 7 exams over 20 years (n=2951). Activity levels were divided into sex-specific tertiles at each exam; long-term activity levels were defined as consistent higher activity (highest tertile in ≥ 2/3 of exams), consistent lower activity (lowest tertile in ≥ 2/3 of exams), or all other patterns. Logistic regression was used to estimate the odds of maintaining a stable weight (body mass index [BMI] ±2 kg/m2 over baseline BMI at all exams). Generalized estimating equation models estimated the relation of long-term activity levels to average yearly changes in BMI over 20 years.
Results: After multivariable adjustment, the odds of maintaining a stable BMI increased by 38% for each increase of 500 exercise units of activity at baseline (OR 1.38, 95% CI 1.11–1.70). As compared with those reporting consistent lower activity levels, those with consistent higher activity levels had an odds ratio of 2.11, 95% CI 1.28–3.45 for maintaining a stable BMI. Annual changes in BMI were smaller among participants who reported consistent higher activity levels compared with those reporting consistent lower activity levels or other patterns (Table⇓).
Conclusion: Higher activity levels at baseline and consistent higher activity over 20 years are associated with higher odds of maintaining a stable weight. Consistent higher activity is associated with less weight gain as young adults transition into middle age.