Association of the triglyceride glucose-Chinese visceral adiposity index with thyroid hormone sensitivity in patients with type 2 diabetes

As hallmarks of type 2 diabetes mellitus (T2DM), insulin resistance and visceral adiposity are both linked to thyroid hormone sensitivity. In this study, we aimed to investigate the association of a novel combined index, the triglyceride-glucose-visceral adiposity index (TyG-CVAI), with thyroid hormone sensitivity in T2DM. In this cross-sectional study, 7023 adult T2DM patients were recruited from two medical centers in China between June 2020 and August 2025. The composite index TyG-CVAI of obesity and insulin resistance is calculated based on triglyceride-glucose index (TyG) and Chinese visceral adiposity index (CVAI). Thyroid hormone sensitivity indicators were represented by thyroid feedback quantile Index (TFQI), thyroid-stimulating hormone index (TSHI), thyrotroph T4 resistance index (TT4RI) and FT3/FT4 ratio. Multivariable linear regression models adjusted for demographic, lifestyle, and clinical confounders were employed to explore the association of TyG-CVAI with thyroid hormone sensitivity indicators. In fully adjusted models, per one-standard deviation increase in TyG-CVAI was significantly associated with elevated TFQI (β = 0.01, 95% CI: 0.00-0.02, P = 0.019), TSHI (β = 0.07, 95% CI: 0.02–0.12, P = 0.005), and TT4RI (β = 3.06, 95% CI: 2.07–4.05, P < 0.001). Participants in the highest TyG-CVAI tertile showed greater increases in these indices compared to the lowest tertile (e.g., TT4RI: β = 6.30, 95% CI: 3.90–8.70, P < 0.001). These associations were robust in sensitivity analyses and more pronounced in women and those with shorter diabetes duration. Higher TyG-CVAI, reflecting combined insulin resistance and visceral adiposity, is associated with impaired thyroid hormone sensitivity in T2DM patients. No applicable.