The Effect of Vitamin C on Endothelial Function of Children with Type 1 Diabetes: An Experimental Study

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.