EVALUATION OF THE RELATIONSHIP BETWEEN THIOSULFATE SULFURTRANSFERASE ACTIVITY AND TRIGLYCERIDE GLUCOSE-BODY MASS INDEX IN TYPE 2 DIABETES MELLITUS

Introduction: The global prevalence of type 2 diabetes mellitus (T2DM) continues to rise dramatically, necessitating reconsideration of underlying pathophysiological mechanisms. Thiosulfate sulfurtransferase (TST), an enzyme involved in mitochondrial function, has emerged as a potential factor in metabolic regulation; however, its relationship with insulin resistance in type 2 diabetes mellitus (T2DM) remains inadequately characterized. Objectives: This study aimed to investigate the relationship between TST activity and insulin resistance, as assessed by the triglyceride glucose index (TyG) and the triglyceride glucose-body mass index (TyG-BMI), in patients with T2DM, potentially identifying new pathways for diagnostic and therapeutic interventions. Methods: In this case-control study, 300 participants (aged 33-65 years) were enrolled, comprising 150 patients with type 2 diabetes mellitus (T2DM) from Al-Wafa Centre for Endocrinology and Diabetes in Mosul, Iraq, and 150 age-matched healthy controls. Serum TST activity was determined spectrophotometrically, while insulin and glucose levels were measured using standardized techniques. TyG and TyG-BMI were calculated using validated formulas. Statistical analyses included independent t-tests and Pearson correlation, with significance set at p ? 0.05. Results: TST activity was significantly decreased by 46% in T2DM patients compared to controls (11.3 ± 5.3 vs. 20.2 ± 4.8 U/mL, p < 0.01). TST activity progressively declined with increasing BMI, showing reductions of 36%, 50%, and 56% in normal weight, overweight, and obese subjects, respectively. T2DM patients exhibited significantly elevated TyG index (4.56±1.3 vs. 3.82±1.1, p<0.01) and TyG-BMI (154.56±18.8 vs. 107.16±11.2, p<0.01). Strong negative correlations were observed between TST activity and both TyG (r=-0.75, p<0.01) and TyG-BMI (r=-0.81, p<0.01). Discussion: Our findings suggest that T2DM is associated with impaired TST activity, potentially resulting from mitochondrial dysfunction. The strong inverse correlation between TST activity and insulin resistance markers indicates that diminished TST function may contribute to metabolic dysregulation in T2DM by impairing glucose uptake and metabolism in insulin-sensitive tissues. Conclusion: TST activity demonstrates significant associations with insulin resistance and obesity in T2DM patients. These findings highlight TST as a potential therapeutic target for improving metabolic function and reducing diabetes complications, warranting further investigation into TST-modulating interventions for the management of type 2 diabetes mellitus (T2DM).