The relationship between microvascular complications and triglyceride-glucose index in patients with diagnosed diabetes mellitus

Objective: Diabetes mellitus is a chronic metabolic disorder characterized by hyperglycemia resulting from insulin deficiency and/or insulin resistance. Prolonged hyperglycemia and insulin resistance lead to damage in various organs and tissues, most notably the eyes, kidneys, nervous system, and cardiovascular system, thereby contributing to the development of microvascular and macrovascular complications. In recent studies, the Triglyceride Glucose (TyG) index has been recognized as a practical and reliable method for assessing insulin resistance. This study aimed to evaluate the relationship between microvascular complications (diabetic retinopathy, nephropathy, and neuropathy) and the TyG index in patients diagnosed with type 2 diabetes mellitus. Within the scope of the study, it was also aimed to investigate whether the TyG index has predictive value for the presence of microvascular complications and whether it could serve as a potential clinical risk marker. Materials and Methods: This retrospective study included 61 patients over the age of 18 who were diagnosed with type 2 diabetes mellitus and presented to the Department of Endocrinology and Metabolism, Çukurova University Faculty of Medicine Hospital, between February 1, 2024 and February 1, 2025. Patient data were collected through a comprehensive review of medical records and clinical documentation. The TyG index was calculated using the formula Ln [fasting triglyceride (mg/dL) × fasting glucose (mg/dL) / 2], based on fasting glucose and triglyceride levels measured at the time of initial presentation. Patients were assessed and categorized with respect to the presence of diabetic retinopathy, nephropathy, and neuropathy, based on clinical examination findings and relevant laboratory parameters. A p-value of < 0.05 was considered indicative of statistical significance in all analyses. Findings: The mean age of the patients was 55.84 years. Of the 61 patients included in the study, 32 ( 52,5 %) were female and 29 ( 47,5 %) were male. In the comparative statistical analysis between patients with and without diabetic retinopathy, the mean age and duration of diabetes were found to be significantly higher in the retinopathy group (p = 0,021, p = 0,045). In the comparison between patients with and without diabetic nephropathy, the duration of diabetes was significantly higher in the nephropathy group (p = 0,043), whereas LDL (p = 0,044) and total cholesterol (p = 0,012) levels were significantly lower. In the comparison between patients with and without diabetic neuropathy, the mean age and duration of diabetes were significantly higher in the neuropathy group (p = 0,020, p = 0,043). No statistically significant relationship was found between the TyG index and the presence of diabetic retinopathy, nephropathy, or neuropathy. Conclusion: In this study, no statistically significant association was found between the TyG index and microvascular complications. The retrospective design of the study and the limited sample size were considered the primary limitations. Therefore, larger-scale, prospective, and multicenter studies are needed to better clarify the relationship between the TyG index and microvascular complications. Keywords: Type 2 Diabetes Mellitus, Triglyceride Glucose (TyG) index, Microvascular Complications, Diabetic Retinopathy, Diabetic Nephropathy, Diabetic Neuropathy