Association between visceral lipid accumulation indicators and advanced cardiovascular-kidney-metabolic syndrome: a cross-sectional study based on NHANES 1999-2018.

Background A newly recognized condition, the cardiovascular-kidney-metabolic (CKM) syndrome,integrated disease spectrum encompassing interlinked renal, cardiovascular, and metabolic dysfunction. Visceral adiposity plays a pivotal role in driving this multisystem deterioration. Although surrogate markers such as the visceral adiposity index (VAI), metabolic score for visceral fat (METS-VF), body roundness index (BRI), and weight-adjusted waist index (WWI) have been proposed to estimate visceral fat burden, their relationship with advanced CKM syndrome remains poorly defined.This study sought to thoroughly examine the links between these indices and advanced CKM risk, and to evaluate their ability to predict such risk. Methods In this study, we performed a cross-sectional analysis using data from the National Health and Nutrition Examination Survey (NHANES) spanning 1999 to 2018, which included 22,019 adults aged 20 years and older. We calculated four indices of visceral fat accumulation (VAI, METS-VF, BRI, WWI) and assessed their associations with advanced CKM syndrome through weighted multivariable logistic regression, restricted cubic spline (RCS) modeling, and receiver operating characteristic (ROC) curve analysis. Subgroup analyses were also conducted to ensure the robustness of the findings, adjusting for demographic and lifestyle factors. Results Advanced CKM syndrome was present in 17.4% of participants. All four indices were significantly associated with advanced CKM (all P < 0.05), with METS-VF showing the strongest association (OR = 1.87, 95% CI: 1.51-2.30). Both METS-VF and VAI demonstrated a non-linear increase in risk for advanced CKM, whereas BRI and WWI showed a positive linear relationship with the risk. Subgroup analyses provided additional evidence, confirming that these associations remained consistent across multiple population subgroups. In ROC analysis, METS-VF demonstrated the highest predictive accuracy (AUC = 0.79), followed by WWI (AUC = 0.73), outperforming traditional markers such as body mass index (BMI) and waist circumference (WC). Conclusions Elevated VAI, METS-VF, BRI, and WWI levels have been significantly linked to advanced CKM syndrome. METS-VF and WWI, as simple and non-invasive markers, show strong predictive capacity and may serve as effective tools for early detection and intervention in clinical settings.