Associations between triglyceride-glucose index combined with waist circumference and heart failure in individuals with different body mass indices: a cross-sectional study using NHANES 2011-2020 data.

Introduction: The incidence of heart failure (HF), a cardiovascular disease, has been widely reported to be gradually increasing. Although the triglyceride-glucose (TyG) index is associated with the risk of HF, this relationship may be affected by differences in nutritional status among individuals with varying levels of obesity. Waist circumference combined with the TyG index may be more accurately associated with HF.

Methods: This study analyzed data from 8769 participants from the 2011-2020 National Health and Nutrition Examination Survey (NHANES). After weighting the data, multivariable logistic regressions were used to calculate the associations between HF and the TyG and TyG-waist circumference (TyG-WC) indices in adults with different body mass indices (BMIs). Restricted cubic splines were employed to assess for linear or nonlinear relationships. Receiver operating characteristic (ROC) curves were used to demonstrate the efficacy of the models for different indices. The Net Reclassification Index (NRI) was used to measure the improvement in the TyG-WC index relative to the TyG index in the different models. The Integrated Discriminant Improvement Index (IDI) supports this conclusion.

Results: TyG and TyG-WC indices were positively associated with HF (TyG: odds ratio [OR], 1.765; 95% CI], 1.390-2.242; P < 0.001; TyG-WC: OR, 1.003; 95% CI, 1.002-1.004; P < 0.001), except In Model 4 for the TyG index (OR, 1.238; 95% CI, 0.941-1.629; P = 0.124). BMI was used to categorize the study population into normal or underweight and overweight or obese groups. In the overweight and obese groups, the odds ratio (OR) increased as the index value increased. However, in the normal and underweight groups, high TyG indices were associated with low ORs. According to the ROC, NRI, and IDI analyses, the TyG-WC index was associated with HF in the normal weight or underweight groups (area under the curve [AUC]: 0.6724; 95% CI: 0.4991-0.6400), whereas the TyG index alone was not (AUC: 0.5695; 95% CI: 0.6115-0.7334). In Model 4, adjusted for all covariates, the TyG index had a slightly better ability than the TyG-WC index (NRI: -0.4112; 95% CI: -0.6818- -0.1406; P < 0.05; IDI: -0.0072; 95%CI: -0.0228-0.0083; P = 0.36256). In the overweight and obese populations, the TyG-WC index was slightly better than the TyG index (NRI: 0.3089; 95% CI: 0.1726-0.4451; P < 0.001; IDI: 0.0084; 95% CI: 0.0017-0.0151; P < 0.05). However, the sensitivity of the TyG-WC index alone was only 41.8%.

Discussion: The association between HF and these two indices was influenced by BMI. In normal-weight and underweight populations, higher TyG indices may imply improved nutritional status. Therefore, the TyG index should be combined with WC to assess the risk of HF. In overweight or obese populations, both indices can be used to assess the risk of HF; however, the TyG-WC index is less sensitive when used alone.