Alpha-lipoic acid administration affects psychological status and markers of inflammation and oxidative damage in patients with type 2 diabetes and coronary heart disease

Background: This investigation was performed to assess the effects of alpha-lipoic acid (ALA) supplementation on psychological status and markers of inflammation and oxidative damage in patients with type 2 diabetes mellitus (T2DM) and coronary heart disease (CHD). Methods: This randomized, double-blind, placebo-controlled trial was performed in 60 patients with T2DM and CHD, aged 45–85 years. Patients were randomized into two groups to receive either 600 mg/day ALA (n = 30) or placebo (n = 30) for 12 weeks. Results: ALA supplementation significantly decreased Beck Depression Inventory index (BDI) (-5.1 ± 3.5 vs. -1.1 ± 4.8, P = 0.001) when compared with the placebo. ALA supplementation resulted also in a significant reduction of serum high sensitivity C-reactive protein (hs-CRP) (-0.8 ± 1.4 vs. +0.5 ± 0.6 mg/L, P < 0.001) and malondialdehyde (MDA) (-0.3 ± 0.2 vs. -0.1 ± 0.3 µmol/L, P = 0.003), and a significant increase in plasma total antioxidant capacity (TAC) levels (+ 26.8 ± 36.0 vs. -4.6 ± 43.4 mmol/L, P = 0.007) when compared with the placebo. ALA intake upregulated transforming growth factor beta (TGF-β) (P = 0.03) and downregulated gene expression of interleukin-1 (IL-1) (P = 0.001) in peripheral blood mononuclear cells of patients with T2DM and CHD as well. Conclusions: ALA supplementation for 12 weeks in patients with T2DM and CHD had beneficial effects on BDI, hs-CRP, TAC, MDA values, and gene expression of IL-1 and TGF-β.