Association of triglyceride glucose index with cardiovascular autonomic neuropathy in type 2 diabetes mellitus

Background Cardiovascular autonomic neuropathy (CAN), defined as impaired autonomic control of the cardiovascular system, is a highly prevalent yet frequently underdiagnosed microvascular complication of diabetes. The triglyceride-glucose (TyG) index, a well-validated surrogate marker of insulin resistance, may have considerable clinical relevance for CAN. Nevertheless, the association between the TyG index and CAN in patients with type 2 diabetes mellitus (T2DM) remains unclear. Methods A total of 230 hospitalized patients with T2DM were recruited from the Department of Endocrinology and Metabolism, Shanghai General Hospital. CAN status was evaluated using the cardiovascular autonomic reflex test (CART) and heart rate variability (HRV) measurements. Meanwhile, demographic characteristics and relevant clinical data were collected, and the TyG index was calculated based on fasting blood glucose and triglyceride levels for subsequent statistical analysis. Results The prevalence of CAN in our cohort of 230 patients was 61.3% (141 cases). Patients with CAN exhibited a significantly higher TyG index compared to those without CAN. The TyG index demonstrated positive correlations with CART parameters (E:I difference, r = 0.301; Valsalva ratio, r = 0.362; 30:15 ratio, r = 0.166; BP change, r = 0.229; all P < 0.05) and inverse correlations with HRV indices (SDNN, r = −0.257; RMSSD, r = −0.226; pNN50, r = −0.226; VLF, r = −0.221; LF, r = −0.253; HF, r = −0.212; TP, r = −0.249; all P < 0.01). Moreover, after adjusting for demographic and metabolic confounders, the TyG index remained a significant independent predictor of CAN. ROC curve analysis indicated that the TyG index possesses favorable discriminatory power for CAN, with an AUC of 0.854 (95% CI: 0.796–0.911, P < 0.001). Conclusions The TyG index shows a distinct association with CAN assessment parameters. As a well-established, effective, and practical surrogate marker of IR, this finding highlights the clinical relevance of the TyG index in diabetes-related complications.