Background: The relationship between life course body mass index (BMI) trajectories and adult cardiovascular disease risk is poorly described. In a well-characterized longitudinal cohort study, we aimed to identify BMI trajectories from early-childhood to adulthood and investigate their association with adverse cardiometabolic phenotypes (type 2 diabetes (T2DM), high risk lipid levels, hypertension, and high carotid intima-media thickness (cIMT)) in middle adulthood.
Methods: We used Latent Class Growth Mixture Modelling to identify distinct BMI trajectories among 2631 Cardiovascular Risk in Young Finns Study participants aged 6-49 years, and Poisson regression with a robust error variance to determine whether trajectory groups predicted each cardiometabolic outcome measured in adulthood.
Results: Six distinct life-course BMI trajectories were identified: stable normal (class 1, 55.2%), high BMI resolving (class 2, 1.6%), progressively overweight stabilizing (class 3, 33.4%), progressively obese increasing (class 4, 4.2%), rapidly overweight stabilising obese (class 5, 4.3%), and overweight or obese persisting (class 6, 1.2%). Higher trajectories were generally associated with increased cardiometabolic risk in middle age. Participants who progressively became overweight (class 3) had greater risks in adulthood compared with those in the stable normal group (class 1) for all considered cardiometabolic phenotypes (risk ratios, RR: 1.47-3.06). Compared with the progressively overweight stabilizing group (class 3), the high BMI resolving group (class 2) had smaller risk ratios for adult T2DM, high-risk lipid levels and hypertension, but increased risk for high cIMT (RR: 3.37 vs. 1.70).
Conclusion: BMI trajectories from childhood to adulthood that reach or persist at high levels are associated with increased cardiometabolic risk in middle age. Stabilizing BMI in obese adults may limit adverse risk profiles and resolution of elevated BMI in young adulthood may substantially reduce cardiometabolic risk. However, to effectively reduce the risk for high adult cIMT, obesity prevention should be targeted at young children.