Impact of Thioctic Acid on Glycemic Indices and Associated Inflammatory-induced Endothelial Dysfunction in Patients with Type 2 Diabetes Mellitus: A Case Control Study

Objective: To evaluate the effects of thioctic acid (TA) add-on metformin therapy on glycemic indices and associated inflammatory reactions induced-endothelial dysfunction (ED) in patients with type 2 diabetes mellitus (T2DM).

Methods: In this case-control clinical study, a total number of 70 patients with T2DM compared with 30 healthy controls were divided into three groups: Group A ( = 30), healthy controls; Group B ( = 36), T2DM patients on metformin and Group C ( = 34), T2DM patients on metformin plus TA 600 mg/day. Anthropometric measurements, lipid profile, and routine biochemical variables were estimated. Serum human vascular cell adhesion molecule-1 (VCAM-1) and E-selectin were measured before and after 10 consecutive week's therapy with metformin and/or TA.

Results: Metformin therapy led to significant reduction of fasting insulin and insulin resistance (IR) with an increment in the insulin sensitivity ( < 0.01). Metformin therapy improved lipid profile compared to the baseline ( < 0.01) with significant reduction of atherogenic index. Metformin plus TA therapy reduced fasting blood glucose, glycated hemoglobin, and IR and showed increment in the insulin sensitivity ( < 0.01) with insignificant effect on fasting insulin ( = 0.09) compared with metformin monotherapy. sVCAM-1 level was high in patients with T2DM (3.74 ± 1.34 ng/ml) at baseline, which decreased by metformin monotherapy to 2.32 ± 0.67 ng/ml or metformin plus TA to 1.98 ± 0.31 ng/ml ( < 0.01), but metformin plus TA illustrated insignificant difference compared to metformin alone ( = 0.29).

Conclusion: TA add on metformin therapy improves glycemic indices and associated inflammatory mediators in patients with T2DM through modulation of IR , IS , and direct direct anti-inflammatory effect.