Trajectories of adiposity indices and the risk of cardiovascular disease and mortality: a prospective cohort study

While novel adiposity indices such as the body roundness index (BRI), a body shape index (ABSI), the visceral adiposity index (VAI), and the Clínica Universidad de Navarra-Body Adiposity Estimator (CUN-BAE) index outperform body mass index (BMI) in predicting cardiovascular disease (CVD) risk, their long-term trajectories remain unstudied in Iran. We investigated the patterns of the BRI/ABSI/VAI/CUN-BAE index and their associations with the risk of CVD, all-cause mortality, and specific-cause mortality among Iranian adults. This prospective cohort study analyzed 11,394 Iranian adults (55.5% women, mean age 41.2 ± 15.0 years) from the Tehran Lipid and Glucose Study (1999–2018). Latent class growth mixture modeling identified trajectories of adiposity indices over a median of 18.0 years. Cox models assessed associations between the trajectories and incident CVD (n = 728), all-cause mortality (n = 532), and cause-specific mortality, adjusting for various socio-demographic, lifestyle, and metabolic confounders. Three distinct trajectories (low, moderate, and high-increase) emerged for all indices, with the high-increasing trajectories showing the strongest associations for CVD risk, the CUN-BAE index (HR: 2.45, 95%CI: 1.73–3.49), BRI (HR: 2.12, 95%CI: 1.65–2.73), ABSI (HR: 2.02, 95%CI: 1.38–2.95), and VAI (HR: 1.92, 95% CI: 1.49–2.49). Besides, the high-increase in BRI was associated with a higher risk of all-cause mortality (HR: 1.47, 95% CI: 1.10–1.96) and cardiovascular mortality (HR: 3.25, 95% CI: 1.85–5.69) compared with the low-increase group. There was no relationship between trajectory in the CUN-BAE index, VAI, and ABSI and risk of all-cause and cause-specific mortality. Notably, no significant associations were observed between any adiposity index trajectories and cancer mortality. Longitudinal trajectories of adiposity indices particularly BRI strongly predict CVD and mortality risks in Iranian adults. These findings support the incorporation of dynamic adiposity measures into clinical risk stratification.