Body mass index modifies cardiovascular risk trajectory: a Chinese longitudinal cohort study

It is still unclear how the risk of cardiovascular disease (CVD) changes across life course and the specific influence of body mass index (BMI) on risk trajectory.

We included 106,962 participants aged 35-74 from a Chinese longitudinal cohort during 1992 to 2021 with 4 repeated measurements. China-PAR (Prediction for Atherosclerotic Cardiovascular Disease Risk in China) equation was applied to calculate 10-year CVD risk. General additional mixed model and Joinpoint model were used to elaborate CVD risk trajectory and the potential benefits of normal BMI.

The 10-year CVD risk for Chinese adults increased from 1.11% [95% confidence interval (CI): 1.00%, 1.22%] to 14.87% (95%CI: 14.76%, 14.99%) dramatically between ages 35-74, with average CVD risk reaching moderate- and high-risk level at 53 and 65 years, respectively. Compared to overweight/obesity (BMI ≥ 25 kg/m²), normal BMI (< 25 kg/m²) could effectively slow the increase of CVD risk during lifespan (average slope: 0.42% vs. 0.33%), and postpone the moderate- and high-risk age window by 4 years and 5 years, respectively. Risk difference between overweight/obesity and normal BMI groups gradually climbed from -0.10% (95%CI: -0.47%, 0.28%) to 3.02% (95%CI: 2.69%, 3.35%) between ages 35-74. Women displayed a similar uptrend, while men experienced peak benefits at 53 years (2.09%, 95%CI: 1.86%, 2.31%) followed by a slight decrease.

This study delineated cardiovascular risk trajectory, identifying critical intervention windows and demonstrating potential cardiovascular benefits of normal BMI, particularly in women.