[Relationship between muscle mass index and triglyceride-glucose index in adults in Xi'an]

Objective: To investigate the relationship between muscle mass index (MMI) and triglyceride-glucose (TyG) index in adults in Xi'an. Methods: Data were derived from the baseline survey of Xi'an urban population cohort, part of the natural population study conducted during 2018-2019 in northwestern China. The TyG index and MMI adjusted by weight (W-MMI) and MMI adjusted by BMI (BMI-MMI) were calculated to investigate their relationship by using logistic regression model. Restricted cubic spline was used to analyze the dose-response relationship between W-MMI or BMI-MMI and TyG index. Sensitivity analysis and subgroup analysis were performed to evaluate the robustness of the results. Results: A total of 3 152 study participants (average age 37.8 years) were included in the analysis. After adjusting for covariates, the participants in the Q₄ group of W-MMI had a 65.7% (OR=0.343, 95%CI:0.227-0.517) lower risk for high TyG compared with those in the Q₁ group. In terms of BMI-MMI, the Q₄ group had a 68.5% (OR=0.315, 95%CI: 0.208-0.478) lower risk for high TyG compared with the Q₁ group. The restricted cubic spline model revealed a significant linear dose-response relationship between muscle mass and TyG. The sensitivity and subgroup analyses showed robust results. Conclusion: In the adult population of Xi'an, MMI was negatively correlated with the TyG index, suggesting that enhancing physical exercise to increase or strengthen muscle mass might help reduce the risk of insulin resistance.