Obesity trajectories based on the European association for the study diagnostic framework and their associations with cardiovascular disease: evidence from two longitudinal cohorts

Cardiovascular disease (CVD) remains a leading global cause of mortality, with obesity being a major modifiable risk factor. The recent European Association for the Study of Obesity (EASO) framework diagnosed obesity by integrating central adiposity and specific complications, advancing beyond body mass index (BMI) alone. However, the association between longitudinal obesity trajectories defined by this framework and CVD risk is unknown. We utilized longitudinal data from the China Health and Retirement Longitudinal Study and the English Longitudinal Study of Ageing. Participants were considered to have obesity if they had a BMI of 30 kg/m2 or higher, or a BMI between 25 and < 30 kg/m2 with waist‑to‑height ratio ≥ 0.5 plus at least one of hypertension, diabetes, arthritis, renal disease, chronic obstructive pulmonary disease, or depression. First, we explored the association between baseline obesity and CVD risk. Second, based on three waves, participants were categorized into five trajectories including no obesity, decreasing obesity, increasing obesity, consistent obesity, and fluctuating obesity. Cox proportional hazards models were used to examine the associations between different obesity trajectories and CVD. A total of 11,858 participants were included in the study. Compared with those without baseline obesity, participants with baseline obesity had a 36% (hazard ratio HR: 1.36, 95% confidence interval CI: 1.26–1.47, p < 0.001) increased risk of CVD incidence. Besides, based on 7,154 enrolled participants, we found that compared to the no obesity group, participants with a consistent and increasing obesity trajectory had a 50% (HR: 1.50, 95% CI: 1.30–1.72, p < 0.001) and 34% (HR: 1.34, 95% CI: 1.11–1.62, p = 0.003) higher risk of CVD. In contrast, decreasing and fluctuating obesity trajectories were not significantly associated with CVD risk. Based on the novel EASO definition of obesity, our study confirmed that baseline obesity was associated with increased CVD risk. Beyond this, dynamic trajectory analyses revealed that both consistent and increasing obesity trajectories were significantly associated with elevated CVD risk. These findings suggest that in CVD prevention, clinical attention should focus on not only the presence of obesity, but also its dynamic progression over time.