Abstract 13246: The Impact of Body-Mass Index Trajectories During Early Adulthood on Cardiac Mechanics in Middle Age: The CARDIA Study

Abstract

Introduction: Obesity is a risk factor for left ventricular dysfunction and incident heart failure. We hypothesized that baseline body mass index (BMI) and trajectories in weight change through young adulthood are associated with abnormal cardiac mechanics in middle age. Methods: We examined 2,735 participants from the Coronary Artery Risk Development in Young Adults (CARDIA) study. BMI was calculated at exam years 0, 2, 5, 7, 10, 15, 20, 25. 2D echo was performed with speckle-tracking analysis. Left ventricular ejection fraction (LVEF) and global longitudinal, circumferential, and radial strain (GLS, GCS, GRS, respectively) were measured at y25. Group-based modeling with latent class analysis (PROC TRAJ) was used to identify trajectories in relative changes in BMI (% change in BMI from baseline at each exam). Linear regression examined associations between baseline BMI and trajectory of BMI change and absolute GLS, GCS, and GRS at y25 adjusting for demographics, risk factors, and echo parameters. Results: Mean age at baseline was 25±4 years. Baseline BMI at y0 was significantly associated with mean GLS at y25 (p=0.01), but not GRS or GCS. We identified 4 distinct trajectories of relative BMI change: stable weight (36% of sample), mild increase (40%), moderate increase (18%), and major increase (6%) in weight (Figure). At y25, there was no difference in LVEF across the 4 BMI trajectory groups (P=NS). After adjustment for clinical variables and baseline BMI, absolute GLS was lower in groups with BMI increases (overall P<0.001). GRS and GCS were not significantly different between the groups. Conclusion: In conclusion, baseline BMI and increases in BMI during young adulthood are significantly associated with the presence of subclinical cardiac dysfunction in middle age despite normal EF. This novel characterization of BMI trajectories across young adulthood may assist in improving understanding of the impact of weight gain and obesity on cardiac dysfunction.