Distinct body mass index trajectories to young-adulthood obesity and their different cardiometabolic consequences

Objective
Different body mass index (BMI) trajectories that result in obesity may have diverse health consequences, yet this heterogeneity is poorly understood. We aimed to identify distinct classes of individuals who share similar BMI trajectories and examine associations with cardiometabolic health.

Approach and Results
Using data on 3,549 participants in the Avon Longitudinal Study of Parents and Children (ALSPAC), a growth mixture model was developed to capture heterogeneity in BMI trajectories between 7·5 and 24·5 years. Differences between identified classes in height growth curves, body composition trajectories, early-life characteristics, and a panel of cardiometabolic health measures at 24·5 years were investigated. The best mixture model had six classes. There were two normal-weight classes: “normal-weight [non-linear]” (35% of sample) and “normal-weight [linear]” (21%). Two classes resulted in young-adulthood overweight: “normal-weight increasing to overweight” (18%) and “normal-weight or overweight” (16%). Two classes resulted in young-adulthood obesity: “normal-weight increasing to obesity” (6%) and “overweight or obesity” (4%). The “normal weight increasing to overweight” class had more unfavourable levels of trunk fat, blood pressure, insulin, high-density lipoprotein cholesterol, left ventricular mass, and E/e′ ratio compared to the “always normal weight or overweight” class, despite the average BMI trajectories for both classes converging at ~26 kg/m2 at 24·5 years. Similarly, the “normal-weight increasing to obesity” class had a worse cardiometabolic profile than the “always overweight or obese” class.

Conclusions
Individuals with high and stable BMI across childhood may have lower cardiometabolic disease risk than individuals who do not become overweight or obese until late adolescence.