The mediation effect of triglyceride glucose index on the risk of thyroid nodule in visceral obese population / 中华内分泌代谢杂志

ABSTRACT

Objective:To investigate the mediation effect of triglyceride glucose index(TyG) on the relation between thyroid nodules and visceral fat area.Methods:A total of 9 324 individuals at the Health Management Center of the First Affiliated Hospital of Zhengzhou University from January 2017 to December 2021 were selected, and the basic information, biochemical indicators, color ultrasound of thyroid were also collected. According to the cut-off value of visceral fat area(VFA) of 100 cm 2 and body mass index(BMI) of 24 kg/m 2, they were divided into four groups: VFA(-)BMI(-), VFA(-)BMI(+ ), VFA(+ )BMI(-), and VFA(+ )BMI(+ ). Chi-square test was used to compare the incidence rate among the four groups, and multivariate logistic regression analysis to indentify influencing factors. TyG and VFA were quartiled, and multivariate logistic regression analysis was used to explore the effects of TyG and VFA on thyroid nodules. The regression coefficient test was used to analyze whether TyG mediated the association between VFA and thyroid nodules. Results:Multivariate logistic regression analysis revealed that compared with VFA(-)BMI(-) group, the VFA(+ )BMI(-) group had the highest risk of thyroid nodules( OR=1.283, 95% CI 1.064-1.546, P=0.009), followed by VFA(+ )BMI(+ ) group( OR=1.245, 95% CI 1.028-1.508, P=0.025). When using TyG and VFA Q1 group as reference, the Q4 group showed an increased risk of thyroid nodule by 1.584 times(95% CI 1.208-2.077, P=0.001) and 1.573 times(95% CI 1.249-1.982, P<0.001), respectively. Mediation analysis indicated that VFA had a direct impact on the incidence rate of thyroid nodules( β=0.162, 95% CI 0.140-0.186, P<0.001). TyG partially mediated the effect of VFA on the incidence rate of thyroid nodules( β=0.103, 95% CI 0.087-0.121, P<0.001), accounting for 38.87% of the total effect. Conclusions:VFA is an independent risk factor for thyroid nodules regardless of BMI. Among individuals with visceral obesity but normal BMI, the incidence rate of thyroid nodules was the highest. In addition, TyG partially mediates the risk of thyroid nodules in patients with visceral obesity. The evaluation of visceral obesity might be of great significance in the early screening and prevention of thyroid nodules.