Revisiting obesity thresholds for cardiovascular disease and mortality risk in Chinese adults: Age- and gender-specific insights

Current obesity classifications may not adequately reflect age- and gender-specific risks in diverse populations. In a prospective cohort study of 166,285 Chinese adults aged ≥40 years without prior cardiovascular disease (CVD) or cancer, we evaluate optimal thresholds of body mass index (BMI), waist circumference (WC), and waist-to-hip ratio (WHR) for predicting incident CVD and all-cause mortality. We observe monotonically increasing dose-response associations of BMI, WC, and WHR with CVD risk but U-shaped relationships with all-cause mortality. The optimal obesity thresholds based on all-cause mortality risk differ by gender, with the lowest mortality risks occurring at BMI 26.3 kg/m 2 , WC 88 cm, and WHR 0.90 in men and BMI 25.4 kg/m 2 , WC 83 cm, and WHR 0.85 in women. Moreover, higher adiposity appears protective in older adults. These findings highlight the need for population-specific obesity criteria to enhance clinical risk assessment and public health strategies.