Effect of body mass index trajectory on lifetime risk of cardiovascular disease in a Chinese population: A cohort study

Background and aims The longitudinal trajectories of body mass index (BMI) can reflect the pattern of BMI changes. Lifetime risk quantifies the cumulative risk of developing a disease over the remaining life of a person. We aimed to identify the trajectory of BMI and explore its association with cardiovascular disease (CVD) in the Chinese population. Methods and results A total of 68,603 participants with a mean age of 55.46 years were included from the Kailuan cohort in Tangshan, China, who were free of CVD and cancer and with repeated measurements of BMI from 2006 to 2010. A latent mixture model was used to identify BMI trajectories. An improved Kaplan-Meier estimator was used to predict the lifetime risk of CVD according to BMI trajectories. During a median follow-up of 7.0 years, 3325 participants developed CVD. Five BMI trajectories were identified at three index ages (35, 45, and 55) respectively. For index age 35 years, compared with the stable low-normal weight group (22.7% [95% CI, 20.0%–25.4%]), the stable high-normal weight (27.6% [25.6%–29.5%]), stable overweight (29.4% [27.4%–31.4%]), stable-low obesity (32.8% [30.0%–35.5%]), and stable-high obesity (38.9% [33.3%–44.5%]) groups had a higher lifetime risk of CVD (P < 0.05). We observed similar patterns for stroke and myocardial infarction. Similarly, the lifetime risk of CVD was higher in the long-term overweight and obese groups at 45 and 55 index ages. Conclusions Long-term overweight and obesity were associated with an increased lifetime risk of CVD. Our findings could assist in predicting the population burden of CVD.