Abstract

Vitamin C and Some Antioxidants Role in Endothelial Dysfunction in Type 2 Diabetic Patients

Author(s):Mahmoud Ragab Mohamed, Bukhary FES, Zakaria Y, Mohsen A, Abdelrahman N, Ismail T.T, Abdel-Raheem S.R.Y

Objective: Endothelial dysfunction (ED) in type-2 diabetes mellitus (DM) plays a crucial role in angiopathies development and progression. The most frequent cause of endothelial dysfunction in DM is oxidative stress. Aim of the study: To investigate the relationship between ascorbic acid level in serum and some anti-oxidant parameters in blood with clinical, and duplex findings of brachial artery and aorta in patients with type 2 -DM. Patients and methods: Case-Control prospective study included sixty patients with type 2-DM, and 20 healthy volunteers were included. History of peripheral ischemia, diabetic retinopathy, frequency of metabolic syndrome was analyzed. Measurements of plasma levels of ascorbate, super oxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GTx) and lipid peroxidase (LPO) were studied. Estimation of HOMA-IR was also done. Duplex study in brachial artery and aorta to measure flow mediated vasodilatation (FMD) reactive hyperemia and intima media thickness (IMT) of aorta was done. Echocardiography was done to measure ejection fraction (EF%) and left ventricular dimensions. Results: Patients’ group showed highly significantly decreased plasma insulin (P=0.009), plasma ascorbate, SOD, CAT and glutathione (P=0.001, each) than control, while showed highly significant increased plasma level of fasting sugar, T-Cholesterol, LDL and lipid peroxidation (P=0.001 each) than control. Urinary ACR was highly significantly also increased in patient’ group (P=0.001) than control. Patients’ group showed highly significant decreased brachial volume blood flow (P=0.008), mean velocity (P= 0.001) and increase IMT of aorta (P=0.001) and LV diameter in diastole (P=0.034) than control. Brachial artery diameter (P=0.001), EF% of LT ventricle (P=0.004), plasma ascorbate (P=0.005) and BMI (P=0.007) were highly significantly predict FMD. While plasma cholesterol (P=0.012), LDL (P=0.018), IMT (P=0.021) and reactive hyperemia (P=0.026) showed less significant prediction to FMD. Plasma ascorbate, SOD, Catalase and glutathione peroxidase showed (100%) diagnostic accuracy for endothelial dysfunction while IMT and lipid peroxidase showed less value (74.4% &89.7%) respectively. Conclusion: Vitamin C, plasm levels of SOD, CAT, glutathione and Lipid peroxidase are decreased in type-2 DM and showed strong relevance to micro and macrovascular complications

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