Association between different triglyceride-glucose index combinations with obesity indicators and arthritis: results from two nationally representative population-based study

Abstract

Background: Insulin resistance (IR) and arthritis are strongly associated, and the triglyceride-glucose (TyG) index combinations with obesity indicators [including TyG-BMI (glucose triglyceride-body mass index), TyG-WC (glucose triglyceride-waist circumference), and TyG-WHtR (glucose triglyceride-waist height ratio)] has recently been recognized as a more effective indicator for assessing IR. However, there is a lack of research on its association with arthritis, and it is also important to assess in different populations.

Methods: The analysis utilized data from the China Health and Retirement Longitudinal Study (CHARLS) and the National Health and Nutrition Examination Survey (NHANES). Arthritis diagnosis relied on self-reporting confirmed by physicians. The association of TyG-BMI, TyG-WC, and TyG-WHtR with arthritis was analyzed through weighted logistic regression models, and exploring nonlinear effects with restricted cubic spline (RCS) models. Secondary and sensitivity analyses included receiver operating characteristic curve (ROC) analysis, comparisons of z score-related odds ratios, subgroup analyses, and multiple imputation.

Results: The study involved 6141 CHARLS participants and 17,091 NHANES participants. Adjusting for confounding variables, TyG-BMI and TyG-WHtR demonstrate a positive correlation with arthritis prevalence in both CHARLS (TyG-BMI: OR = 1.02, 95% CI 1.00-1.04; TyG-WHtR: OR = 1.13, 95% CI 1.03-1.24) and NHANES (TyG-BMI: OR = 1.07, 95% CI 1.06-1.08; TyG-WHtR: OR = 1.50, 95% CI 1.40-1.60). RCS regression analysis demonstrated a significant nonlinear association. ROC analysis indicated that TyG-BMI and TyG-WHtR were superior to TyG for the diagnosis of arthritis in both CHARLS and NHANES.

Conclusions: TyG-BMI and TyG-WHtR demonstrate a positive correlation with arthritis prevalence in both Chinese and the U.S. populations, displaying superior diagnostic relevance compared to TyG.

Keywords: Arthritis; CHARLS; NHANES; TyG; TyG–BMI; TyG–WC; TyG–WHtR.

Fig. 1

Flow diagram of the screening of the Chinese and the U.S. participants in CHARLS 2011–2012 and NHANES 1999–2018

Fig. 2

Association of TyG–BMI, TyG–WC, and TyG–WHtR with arthritis of the Chinese and the U.S. participants in CHARLS 2011–2012 and NHANES 1999–2018. CHARLS: China Health and Retirement Longitudinal Study; CI: confidence interval; HDL: high-density lipoprotein; NHANES: National Health and Nutrition Examination Survey; OR: odds ratios; PIR: poverty income ratio; Q2: second quartile; Q3: third quartile; TyG: triglyceride–glucose; TyG–BMI: glucose triglyceride–body mass index; TyG–WC: glucose triglyceride–waist circumference; TyG–WHtR: glucose triglyceride–waist height ratio. ^aQuartile 1 is the reference category. ^bThe crude model did not adjust for covariates, while the adjusted model adjusted for age, sex, race/ethnicity, marital status, education level, household income/PIR, drinking status, smoke, hypertension, total cholesterol, HDL. ^cTyG–BMI was treated as a continuous variable with per 10-unit increase. ^dTyG–WC was treated as a continuous variable with per 100-unit increase

Fig. 3

Association of TyG–BMI, TyG–WC, and TyG–WHtR with rheumatoid arthritis and osteoarthritis of the U.S. participants in NHANES 1999–2018. CI: confidence interval; HDL: high-density lipoprotein; NHANES: National Health and Nutrition Examination Survey; OR: odds ratios; PIR: poverty income ratio; Q2: second quartile; Q3: third quartile; TyG: triglyceride-glucose; TyG–BMI: glucose triglyceride–body mass index; TyG–WC: glucose triglyceride–waist circumference; TyG–WHtR, glucose triglyceride–waist height ratio. ^aQuartile 1 is the reference category. ^bThe crude model did not adjusted for covariates, while the adjusted model adjusted for age, sex, race/ethnicity, marital status, education level, PIR, drinking status, smoke, hypertension, total cholesterol, HDL. ^cTyG–BMI was treated as a continuous variable with per 10-unit increase. ^dTyG–WC was treated as a continuous variable with per 100-unit increase

Fig. 4

Association of TyG–BMI, TyG–WC, and TyG–WHtR with arthritis of the Chinese and the U.S. participants in CHARLS 2011–2012 and NHANES 1999–2018 by RCS. a The model adjusted for age, sex, race/ethnicity, marital status, education level, household/PIR income, drinking status, smoke, hypertension, total cholesterol, HDL