The association between weight-adjusted waist circumference index and risks of cardiovascular and all-cause mortality: a retrospective analysis based on the NHANES database

BACKGROUND: Nowadays, obesity has become a public health issue. Weight-adjusted waist circumference index (WWI) is gaining attention as a new obesity indicator. Evidence regarding the association between WWI and all-cause mortality and cardiovascular mortality among the general adult population in the United States remains limited. METHODS: This retrospective cohort study analyzed 3,081 U.S. adults from the 1999-2018 NHANES database. Weighted Cox regression, trend chi-square test, Kaplan-Meier analysis, and comprehensive predictive performance assessments were used to explore the association between WWI and all-cause/cardiovascular mortality, and validate WWI's predictive value versus BMI/waist circumference/body weight. Subgroup and interaction analyses were also performed. RESULTS: < 0.001). WWI had higher AUC than traditional indices, with significant DeLong test differences, stable long-term predictive performance, and superior net benefit in clinically relevant DCA threshold ranges. CONCLUSION: This study demonstrates a significant association between WWI and all-cause mortality and cardiovascular mortality among the general adult population in the United States, Our findings suggest that older people, women, low-income and low-educated people, smokers have higher WWI, and people with high WWI also have higher prevalence of hypertension and diabetes, Integrating WWI into clinical risk assessment may help identify high-risk populations and guide targeted interventions to reduce mortality risk.