The effects of combined magnesium and zinc supplementation on metabolic status in patients with type 2 diabetes mellitus and coronary heart disease

Background The present research aimed to analyze the impacts of magnesium and zinc supplements on glycemic control, serum lipids, and biomarkers of oxidative stress and inflammation in patients suffering from coronary heart disease (CHD) and type 2 diabetes mellitus (T2DM). Methods According to the research design, a randomized, double-blind, placebo-controlled trial has been implemented on 60 subjects suffering from CHD and T2DM. Therefore, participants have been randomly divided into 2 groups for taking placebo (n = 30) or 250 mg magnesium oxide plus 150 mg zinc sulfate (n = 30) for 12 weeks. Results Magnesium and zinc significantly decreased fasting plasma glucose (FPG) (beta - 9.44 mg/dL, 95% CI, - 18.30, - 0.57; P = 0.03) and insulin levels (beta - 1.37 mu IU/mL, 95% CI, - 2.57, - 0.18; P = 0.02). Moreover, HDL-cholesterol levels significantly enhanced (beta 2.09 mg/dL, 95% CI, 0.05, 4.13; P = 0.04) in comparison to the placebo. There was an association between magnesium and zinc intake, and a significant decrease of C-reactive protein (CRP) (beta - 0.85 mg/L, 95% CI, - 1.26, - 0.45; P < 0.001), a significant increase in total nitrite (beta 5.13 mu mol/L, 95% CI, 1.85, 8.41; P = 0.003) and total antioxidant capacity (TAC) (beta 43.44 mmol/L, 95% CI, 3.39, 83.50; P = 0.03) when compared with placebo. Furthermore, magnesium and zinc significantly reduced the Beck Depression Inventory index (BDI) (beta - 1.66; 95% CI, - 3.32, - 0.009; P = 0.04) and Beck Anxiety Inventory (BAI) (beta - 1.30; 95% CI, - 2.43, - 0.16; P = 0.02) when compared with the placebo. Conclusions In patients with T2DM and CHD, the 12-week intake of magnesium plus zinc had beneficial effects on FPG, HDL-cholesterol, CRP, insulin, total nitrite, TAC levels, and BDI and BAI score. This suggests that magnesium and zinc co-supplementation may be beneficial for patients with T2DM and CHD. Further studies on more patients and lasting longer are needed to determine the safety of magnesium and zinc co-supplementation.