Association of weight-adjusted waist index with cardiovascular disease and mortality among metabolic syndrome population

Abstract

Metabolic syndrome (MetS) is prevalent and significantly impacts global public health, with obesity being a major risk factor for cardiovascular diseases (CVD) and mortality. Traditional metrics like body mass index (BMI) have limitations in assessing obesity-related risks. The weight-adjusted waist circumference index (WWI) has emerged as a novel obesity metric, this study aimed to evaluate the association of WWI with CVD and mortality in MetS patients. This study used data from 12,641 participants with MetS, derived from the National Health and Nutrition Examination Survey (NHANES) conducted from 1999 to 2020. The WWI was calculated, and its association with CVD and mortality was assessed using multivariate logistic and Cox regression models. The study controlled for potential confounders and performed subgroup and sensitivity analyses to validate the robustness of the findings. The predictive performance of WWI was evaluated using the area under the receiver operating characteristic curve (ROC). Kaplan-Meier (KM) curves further were used to evaluate the associations between WWI and mortality of the MetS population. As WWI values escalated, there was a proportional rise in the risk of CVD and mortality in MetS. The fully adjusted continuous model revealed a 32.0% elevated likelihood of CVD development, a 69.5% increased probability of heart failure (HF), a 51.1% heightened risk for CVD mortality, and a 22.8% augmented risk for all-cause mortality with each one-unit increment in WWI. Comparing the highest to the lowest quartile of WWI, the top quartile exhibited a significantly increased risk of CVD (odds ratio [OR] = 1.883; 95% confidence interval [CI]: 1.276-2.633, p-value = 0.001), HF (OR = 2.909; 95% CI: 1.490-5.677, p-value = 0.002), CVD mortality (hazard ratio [HR] = 2.088; 95% CI: 1.279-3.409, p-value = 0.003), and all-cause mortality (HR = 1.394; 95% CI: 1.070-1.816, p-value = 0.014) among individuals with MetS. Sensitivity and subgroup analyses substantiated the consistency and stability of these associations across various demographic groups. The ROC analysis demonstrated that WWI outperforms BMI in predicting adverse outcomes in MetS. The KM curves validated that higher WWI values was correlated with diminished survival rates in MetS population. The WWI served as a significant indicator for assessing the risk of CVD and mortality in the MetS population. This study recommended the regular assessment of WWI in MetS individuals for evaluating their risk of CVD and mortality, potentially enhancing preventive and treatment strategies for this patient population.

Keywords: MetS; Metabolic syndrome; NHANES; WWI; Weight-adjusted waist circumference index.

Figure 1

Flowchart of participants’ selection. MetS, metabolic syndrome; CVD, cardiovascular disease; WWI, weight-adjusted waist circumference index.

Figure 2

Composition ratio of patients with metabolic syndrome under different group conditions. (A) grouped by age; (B) grouped by gender; (C) grouped by race; (D) grouped by cardiovascular disease (CVD); (E) grouped by CVD mortality; (F) grouped by all-cause mortality.

Figure 3

Stratified analyses of weight-adjusted waist circumference index (WWI). (A) associations between WWI and cardiovascular disease (CVD); (B) associations between WWI and heart failure (HF); (C) associations between WWI and CVD mortality; (D) associations between WWI and all-cause mortality. DM diabetes; CKD chronic kidney disease.

Figure 4

Receiver operating characteristic (ROC) curve analysis of the weight-adjusted waist circumference index (WWI) and body mass index (BMI). (A) ROC of WWI to cardiovascular disease (CVD); (B) ROC of WWI to heart failure (HF); (C) ROC of WWI to CVD mortality; (D) ROC of WWI to all-cause mortality; (E) ROC of BMI to CVD; (F) ROC of BMI to HF; (G) ROC of BMI to CVD mortality; (H) ROC of BMI to all-cause mortality. Sens sensitivity; Spec specificity; PPV positive predictive value; NPV negative predictive value; AUC area under curve.

Figure 5

Kaplan–Meier curve analysis of the weight-adjusted waist circumference index (WWI) and body mass index (BMI). (A) cardiovascular-specific survival with different quartiles of WWI; (B) overall survival with different quartiles of the WWI; (C) cardiovascular-specific survival grouped by cutoff value of WWI to cardiovascular disease (CVD) mortality; (D) overall survival grouped by cutoff value of WWI to all-cause mortality; (E) cardiovascular-specific survival with different quartiles of BMI; (F) overall survival with different quartiles of the BMI; (G) cardiovascular-specific survival grouped by cutoff value of BMI to CVD mortality; (H) overall survival grouped by cutoff value of BMI to all-cause mortality. WWIQ quartiles of the WWI; BMIQ quartiles of the BMI; WWIHL WWI high or low; BMIHL BMI high or low.