Skrha Jan, Prázný Martin, Hilgertová Jirina, Weiserová Hana
Laboratory for Endocrinology and Metabolism, Department of Internal Medicine 3, Faculty of Medicine 1, Charles University, Prague, Czech Republic.
Clin Chim Acta. 2003 Mar;329(1-2):103-8. doi: 10.1016/s0009-8981(03)00007-x.
Alpha-tocopherol and ascorbic acid form a part of scavenger system influencing the level of oxidative stress in diabetes mellitus. The aim of this study was to evaluate serum concentrations of alpha-tocopherol and ascorbic acid in Type 1 and Type 2 diabetes mellitus and to compare them with the presence of vascular complications as well as with oxidative stress and endothelial dysfunction.
A total of 38 Type 1 and 62 Type 2 diabetic patients were subdivided into those with and without angiopathy. Serum alpha-tocopherol and ascorbic acid concentrations were estimated in all patients and in 38 healthy persons. Their results were compared with diabetes control, with oxidative stress measured by plasma malondialdehyde and with endothelial dysfunction estimated by serum N-acetyl-beta-glucosaminidase activity. In addition, the differences in biochemical variables were compared between patients with and without angiopathy.
Serum alpha-tocopherol related to the sum of cholesterol and triglyceride concentrations (AT/CHT ratio) was significantly lower in diabetic patients with macroangiopathy than in those without vascular changes (p<0.05). Serum ascorbic acid levels were significantly lower only in Type 2 diabetic patients with macroangiopathy as compared with healthy controls as well as with patients without vascular disease (p<0.01). Positive relationship was observed between serum alpha-tocopherol and cholesterol or triglyceride concentrations in both Type 1 and Type 2 diabetic patients. The presence of oxidative stress together with endothelial dysfunction measured by N-acetyl-beta-glucosaminidase activity was accompanied by lower AT/CHT ratio (p<0.005) in Type 2 diabetic patients.
Diabetic patients with proven angiopathy or with advanced oxidative stress and endothelial dysfunction have significantly lower AT/CHT ratio and ascorbic acid concentration in serum. Their low concentrations may participate at the increased level of oxidative stress in these individuals.
α-生育酚和抗坏血酸是清除剂系统的一部分，影响糖尿病患者的氧化应激水平。本研究旨在评估1型和2型糖尿病患者血清中α-生育酚和抗坏血酸的浓度，并将其与血管并发症的存在情况、氧化应激及内皮功能障碍进行比较。
将38例1型糖尿病患者和62例2型糖尿病患者分为有血管病变组和无血管病变组。测定所有患者及38名健康人的血清α-生育酚和抗坏血酸浓度。将结果与糖尿病控制情况、通过血浆丙二醛测定的氧化应激以及通过血清N-乙酰-β-氨基葡萄糖苷酶活性评估的内皮功能障碍进行比较。此外，比较有血管病变和无血管病变患者生化变量的差异。
患有大血管病变的糖尿病患者血清α-生育酚与胆固醇和甘油三酯浓度之和的比值（AT/CHT比值）显著低于无血管病变者（p<0.05）。与健康对照组以及无血管疾病的患者相比，仅患有大血管病变的2型糖尿病患者血清抗坏血酸水平显著降低（p<0.01）。在1型和2型糖尿病患者中，血清α-生育酚与胆固醇或甘油三酯浓度之间均呈正相关。在2型糖尿病患者中，存在氧化应激以及通过N-乙酰-β-氨基葡萄糖苷酶活性测定的内皮功能障碍时，AT/CHT比值较低（p<0.005）。
已证实有血管病变或存在晚期氧化应激及内皮功能障碍的糖尿病患者，其血清AT/CHT比值和抗坏血酸浓度显著降低。这些低浓度可能与这些个体氧化应激水平升高有关。
