Abstract P021: Secular and Aging-Related Weight Gain Slows among U.S. Adults: The CARDIA Study
Introduction: Nearly 69% of U.S. adults are overweight or obese, although recent national data suggest the increasing prevalence of obesity has slowed. However, these data do not address age-related weight changes within individuals. The 25-year prospective Coronary Artery Risk Development in Young Adults (CARDIA) study provides an opportunity to use longitudinal data across different age groups to partition weight change due to aging and secular trends in a bi-racial sample examined since young adulthood.
Methods: Of the 5,115 Black and White men and women initially assessed in 1985-86, 3,404 had weight measured at Year 25 (2010-11). This included 649 Black men (BM), 936 Black women (BW), 855 White men (WM), and 964 White women (WW). Linear mixed models of 25-year weight change for the four race-sex groups estimated the overall weight change, partitioned into age and secular components of weight change. The secular component was derived from reaching the same age at different calendar times. Women were excluded if pregnant at a particular exam. Data of participants reporting bariatric surgery were excluded for all exams following surgery.
Results: All four race-sex groups demonstrated significant increases in weight (kg) from baseline to Year 25: +18.5 (BM), +20.9 (BW), +13.9 (WM), and +13.8 (WW). The proportion of weight gain attributable to secular trends was significant for all four race-sex groups at each follow-up time period (i.e., Years 5, 10, 15, 20, and 25), ps<0.0001. Over the 25-year follow-up, average weight gain (kg/year) attributable to secular trend was 0.65 (BM), 0.78 (BW), 0.57 (WM), and 0.36 (WW). However, a quadratic model best represented the 25-year secular trends for BM, BW, and WW, such that the slope of weight gain was more pronounced at earlier exams. Weight gain attributable to aging was also best represented by a quadratic model for BM, BW, and WM, such that age-related weight gain was more pronounced at younger ages, which was particularly consistent among men who experienced the most weight gain in their teens and 20s. For instance, BM and WM aged 17-20 gained an additional 1.72 kg/year and 1.47 kg/year, respectively, than BM and WM aged 21-23. In contrast, age-related weight gain was most apparent between the mid-20s and mid-30s for WW.
Conclusions: Consistent with previous findings, early adulthood is a high-risk period for weight gain and may be a critical period to target obesity prevention efforts. WW appear to differ from the other demographic groups in that weight gain occurred later in adulthood. Overall, findings suggest that both age-related and secular weight gain trends are attenuated in later middle age and in more recent calendar time.
- © 2013 by American Heart Association, Inc.