Fig. 6

Mediating role of IR-related indices in the impact of central obesity indices on HT risk. BMI, body mass index; WC, waist circumference; WHtR, waist-to-height; WHR, waist to hip ratio; LAP, lipid accumulation product; VFA, visceral fat area; TyG, triglyceride glucose index; TyG-BMI = TyG × BMI; TyG-WC = TyG × WC; TyG-WHR = TyG × WHR; TyG-WHtR = TyG × WHtR. Mediation analysis was conducted using the triglyceride -glucose and its four derivative indices—TyG, TyG-BMI, TyG-WC, TyG-WHR, TyG-WHtR—as mediators. The total effect of central obesity-related indices (WC, WHtR and WHR) on Hashimoto thyroiditis was divided into direct effects and mediation effects through the triglyceride-glucose and its derivative indices. The mediation proportion and statistical significance were calculated. Model 1 was unadjusted. Model 2 was adjusted for age, sex, years of education, married, current smoking, current drinking, hemoglobin A1c, duration of diabetes, dyslipidemia, hypertension, take lipid-lowering drugs, regular exercise, diabetic dietary pattern, uric acid, urea nitrogen related to creatinine, alanine aminotransferase, aspartate aminotransferase, thyroid stimulating hormone, homeostasis model assessment of IR, take hypoglycemic drugs. ^* P < 0.05, ^** P < 0.001