Mediating effect of TyG index on the association between glucose-lipid metabolism-related dietary pattern and T2DM: a propensity score-matched analysis.

Objective: This study aimed to investigate the association of dietary patterns (DPs) with risk of T2DM, emphasizing the intermediary role of HOMA or TyG indices among a Chinese adult population.

Research design and methods: Directed acyclic graphs combined with propensity score matching were used to minimize confounding, resulting in 1330 subjects for final analysis. Principal component analysis and reduced rank regression, applied to eleven food groups. Multivariable logistic regression and restricted cubic spline regression models were used to assess associations between there DPs with prevalent T2DM, as well as insulin resistance and β-cell function (HOMA-TyG). Mediation analyses were conducted to evaluate whether the HOMA-TyG index mediated the relationship between DPs and T2DM.

Results: The DP1, characterized by high intakes of poultry, meat, and preserved foods, was associated with elevated body mass index, triglycerides, and hemoglobin A1c. Both PCA-DP1(OR_Q4VsQ1 = 2.15, 95% CI: 1.53-3.03) and RRR-DP1 (OR_Q4VsQ1 = 1.69, 95% CI: 1.82-3.58) were significantly positively correlated with T2DM. RRR-DP1 additionally demonstrated a dose-dependent relationship with HOMA-insulin resistance and TyG. Furthermore, the TyG index mediated approximately 19.51% of the relationship between RRR-DP1 and T2DM.

Conclusions: These findings indicate that glucose-lipid metabolism-related dietary pattern, notably high in animal fat, exacerbates insulin resistance and heightens T2DM risk. Tailoring dietary interventions to modify this pattern may be an effective strategy for preventing and managing T2DM.