Raygan F, et al. - The effects of melatonin administration on metabolic status in diabetic patients with coronary heart disease (CHD) was evaluated in this randomized, double-blind, placebo-controlled trial. Beneficial effects were observed on the plasma glutathione (GSH), nitric oxide (NO), malondialdehyde (MDA), protein carbonyl (PCO), serum high sensitivity C-reactive protein (hs-CRP) levels, glycemic control, HDL-cholesterol, total-/HDL-cholesterol ratio, blood pressures and parameters of mental health, as a result of melatonin supplementation for 12 weeks in diabetic patients with CHD.

Methods

• The researchers conducted this randomized, double-blind, placebo-controlled trial.
• They enrolled 60 diabetic patients with CHD in this study.
• They randomly allocated subjects into 2 groups to receive either 5 mg melatonin (n = 30) or placebo (n = 30) twice a day for 12 weeks.

Results

• Melatonin supplementation, compared with the placebo, resulted in significant increases in plasma GSH (+64.7 ± 105.7 vs -11.1 ± 137.6 μmol/L, P=0.02) and NO (+0.9 ± 4.7 vs -3.3 ± 9.6 μmol/L, P=0.03), and significant decreases in MDA (-0.2 ± 0.3 vs +0.1 ± 0.5 μmol/L, P=0.007), PCO (-0.12 ± 0.08 vs +0.03 ± 0.07 mmol/mg protein, P < 0.001) and serum hs-CRP levels (-1463.3 ± 2153.8 vs +122.9 ± 1230.4 ng/mL, P=0.001).
• The use of melatonin, compared with the placebo, significantly reduced fasting plasma glucose (-29.4 ± 49.0 vs -5.5 ± 32.4 mg/dL, P=0.03), serum insulin concentrations (-2.2 ± 4.1 vs +0.7 ± 4.2 μIU/mL, P=0.008), homeostasis model of assessment-estimated insulin resistance (-1.0 ± 2.2 vs +0.01 ± 1.6, P=0.04), total-/HDL-cholesterol ratio (-0.18 ± 0.38 vs +0.03 ± 0.35, P=0.02) and systolic (-4.3 ± 9.6 vs +1.0 ± 7.5 mmHg, P=0.01) and diastolic blood pressure (-2.8 ± 7.3 vs +0.1 ± 3.6 mmHg, P=0.04).
• Furthermore, melatonin treatment significantly increased quantitative insulin sensitivity check index (+0.006 ± 0.01 vs -0.004 ± 0.01, P=0.01) and serum HDL-cholesterol (+2.6 ± 5.5 vs -0.01 ± 4.4 mg/dL, P=0.04).
• No significant effect on other metabolic parameters was observed with melatonin supplementation.