RESUMO
BACKGROUND: Improvement of endothelial dysfunction could prevent or delay the occurrence of the atherosclerosis process in patients with Kawasaki disease (KD). It is suggested that Vitamin C could improve endothelial dysfunction. In this study, we investigated whether administration of Vitamin C as a water-soluble antioxidant could be effective in this regard among patients with KD. MATERIALS AND METHODS: In this case control analytic-experimental study, children aged 3-18 years with KD, and a group of healthy children evaluated. Vitamin C (250 mg/daily) administrated for the two studied groups for 1 month. Endothelial function evaluated by flow-mediated dilatation (FMD) and intima-media thickness (IMT) measurement using vascular Doppler ultrasonography, before and after trial. RESULTS: In this study, 16 patients with KD and 19 normal children were studied. At baseline mean of IMT and FMD was not different in the two studied groups (P > 0.05). After Vitamin C administration IMT decreased significantly in two studied groups (from 27.06 ± 6.27 to 21.56 ± 3.77 in KD group and from 27.66 ± 5.66 to 23.33 ± 3.66 in control group [P < 0.05]). FMD increased in two studied groups, but the difference was significant in the control group (from 6.84 ± 2.51 to 7.03 ± 2.87 in KD group and from 6.53 ± 2.36 to 7.82 ± 2.14 in the control group). CONCLUSION: Vitamin C might improve the endothelial function of patients with KD.
RESUMO
BACKGROUND: It is well established that improvement of endothelial dysfunction (ED) could prevent or delay the occurrence of cardiovascular disease (CVD) and its related morbidity and mortality in patients with chronic kidney disease (CKD). In this study we investigated whether administration of vitamin C could be effective by improving brachial artery flow-mediated dilation (FMD) and intima media thickness (IMT), two surrogate markers of ED, in children with CKD or chronic renal failure (CRF). MATERIALS AND METHODS: In this analytic-experimental study children aged 3-18 years with a diagnosis of CRF and a group of healthy children were enrolled. Vitamin C (250 mg/day) administrated for the two studied groups for 1 month. Endothelial function was evaluated by FMD and IMT measurement using vascular Doppler ultrasonography, before and after trial. RESULTS: In this study 18 patients with CRF and 19 normal children as the control group were studied. At baseline mean of IMT and FMD was not different in the two studied groups (P > 0.05). After vitamin C administration IMT decreased significantly in the two studied groups (P < 0.05). FMD increased in the two studied groups but the difference was significant in the control group (P < 0.05). CONCLUSION: The findings of this interventional trial have demonstrated that vitamin C could have protective effect on ED of patients with CRF possibly in those with severe form of the disease but for obtaining more conclusive results larger sample size is needed.
RESUMO
BACKGROUND: Considering the importance of improvement of endothelial function in patients with type 1 diabetes mellitus (DM) and to prevent its related micro- and macro-vascular complications; in this study, the effect of vitamin C administration on improving endothelial function of children with type 1 diabetes was investigated. METHODS: In this analytic-experimental study, children with type 1 DM aged 6-18 years and a group of healthy children enrolled. Vitamin C (250 mg/daily) administrated for the two studied groups for 1-month. Endothelial function evaluated by flow-mediated dilatation (FMD) and intima-media thickness (IMT) measurement using vascular Doppler ultrasonography, before and after trial. RESULTS: In this study, 18 patients with type 1 diabetes (DM) and 19 normal children as the control group were studied. After vitamin C administration IMT reduced in all studied groups (P < 0.05). FMD increased in all studied groups, but it was significant only in the control group (P = 0.02 in the control group and P = 0.07 in patients with DM). Mean differences of IMT 2 - IMT 1, FMD 2 - FMD 1 and left ventricular (LV) mass 2 - LV mass 1 and blood pressure (BP) were not significantly different in two studied groups (P > 0.05). Mean differences of IMT 2 - IMT 1, FMD 2 - FMD 1, LV mass 2 - LV mass 1 and BP were not significantly different in patients with HbA1c ≤ 7 g/dl and those with HbA1c >7 g/dl and control group (P > 0.05). CONCLUSIONS: The findings of the current study indicated that vitamin C may have a protective effect on endothelial dysfunction, but regarding its effectiveness among the high-risk population such as diabetic patients with and without appropriate glycemic control the study was not sufficiently powered due to its small sample size.