Effects of quercetin supplementation on endothelial dysfunction biomarkers and depression in post-myocardial infarction patients: A double-blind, placebo-controlled, randomized clinical trial.

BACKGROUND: Endothelial dysfunction and depression are highly prevalent in patients who have experienced a myocardial infarction (MI). Epidemiological studies have pointed out that a diet rich in flavonoids, e.g., quercetin, can prevent the development of these biological phenomena. Therefore, we aimed to investigate the effects of quercetin supplementation on the levels of intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1) and on depression in post-MI subjects. METHODS: Eighty-eight post-MI patients who had experienced their first MI (body mass index ≤35 kg/m2, age 30-65 years) were recruited from the Rasool-e-Akram and Afshar Hospitals, Iran, and included in this randomized, placebo-controlled, double-blind parallel study. The participants were randomly assigned to receive a daily dose of 500 mg quercetin (n = 44) or placebo (n = 44) for 8 weeks. Serum concentrations of ICAM-1 and VCAM-1 were quantified by ELISA and depression levels were assessed using the Beck's Depression Inventory (BDI-II) questionnaire at baseline and at 8-week follow-up. RESULTS: Seventy-six participants completed the study, but the intention-to-treat (ITT) analysis was conducted for all 88 participants who were randomized into the intervention groups. No significant changes in serum concentrations of ICAM-1 or VCAM-1 (P = 0.21 and P = 0.80, respectively) were observed after 8 weeks of quercetin supplementation versus placebo. In addition, depression levels did not differ significantly between the quercetin and placebo groups. CONCLUSION: Our findings demonstrated that in post-MI patients, daily supplementation with quercetin (500 mg/day) for 8 weeks did not affect endothelial dysfunction biomarkers and depression levels. This trial was registered at IRCT.ir as IRCT20190428043405N1.

Effects of quercetin supplementation on inflammatory factors and quality of life in post-myocardial infarction patients: A double blind, placebo-controlled, randomized clinical trial.

Myocardial infarction (MI) is one of the leading causes of death in the world. Epidemiological studies have shown that dietary flavonoids are inversely related to cardiovascular morbidity and mortality. The study aimed to determine whether quercetin supplementation can improve inflammatory factors, total antioxidant capacity (TAC) and quality of life (QOL) in patients following MI. This randomized double-blind, placebo-controlled trial was conducted on 88 post-MI patients. Participants were randomly assigned into quercetin (n = 44) and placebo groups (n = 44) receiving 500 mg/day quercetin or placebo tablets for 8 weeks. Quercetin supplementation significantly increased serum TAC compared to placebo (Difference: 0.24 (0.01) mmol/L and 0.00 (0.00) mmol/L respectively; p < .001). TNF-α levels significantly decreased in the quercetin group (p = .009); this was not, however, significant compared to the placebo group. As for QOL dimensions, quercetin significantly lowered the scores of insecurity (Difference: -0.66 (12.5) and 0.00 (5.55) respectively; p < .001). No significant changes in IL-6, hs-CRP, blood pressure and other QOL dimensions were observed between the two groups. Quercetin supplementation (500 mg/day) in post-MI patients for 8 weeks significantly elevated TAC and improved the insecurity dimension of QOL, but failed to show any significant effect on inflammatory factors, blood pressure and other QOL dimensions.

Vitamin D supplementation and serum heat shock protein 60 levels in patients with coronary heart disease: a randomized clinical trial.

BACKGROUND: The aim in this study was to investigate the effect of vitamin D (25(OH)D3) supplementation on heat shock protein 60 (HSP 60) and other inflammatory markers (IL-17, TNF-α, PAB) in patients with coronary heart disease (CHD). METHODS: In this double-blind, randomized clinical trial, we recruited 80 male and female patients aged 30-60 with CHD and 25(OH)D3 serum levels < 30 ng/ml from Rasool-e-Akram Hospital in Tehran, Iran. Serum levels of HSP 60 as primary outcome, and 25(OH)D3, IL-17, TNF-α, PAB, lipid profiles and parathyroid hormone (PTH) as secondary outcomes were measured at baseline and post-intervention. We randomly assigned eligible participants to a placebo group (N = 40) or an intervention group (N = 40) (50,000 IU/wk. vitamin D supplement) for eight weeks. RESULTS: The results demonstrated that vitamin D supplementation resulted in a significant increase in 25(OH) D3 serum levels in the intervention group compared to the placebo group (46.86 vs. 7.28 ng/ml). PTH levels decreased in the intervention group compared to the placebo group (- 19.81 vs. 2.92 pg/ml) after eight weeks of supplementation. Furthermore, we observed a significant change in waist circumference (- 0.97 vs. -0.26 cm), fat percentage (-.13 vs. 0.1%), systolic blood pressure (- 3.85 vs. -2.11 mmHg) and diastolic blood presure (- 4 vs. -1.86 mmHg) in the vitamin D group compared to the placebo group (all P values < 0.05). Other variables did not significantly change after the intervention. CONCLUSION: Based on our findings, weekly vitamin D supplementation of 50,000 IU for eight weeks in patients with CHD resulted in decreased systolic and diastolic blood pressure, waist circumference and fat percentage. No significant effect on HSP 60, inflammatory markers or lipid profiles was observed. TRIAL REGISTRATION: IRCT, IRCT201612122365N14. Registered 12 December 2016.