Jennings P E, Chirico S, Jones A F, Lunec J, Barnett A H
Department of Clinical Chemistry, Selly Oak Hospital, UK.
Diabetes Res. 1987 Nov;6(3):151-4.
Recent evidence has suggested that diabetic microangiopathy is associated with increased free radical induced oxidative damage. Ascorbic acid (AA) is a free radical scavenger and using a specific HPLC method we have investigated its concentration and that of its oxidized metabolite dehydroascorbic acid (DHAA) in diabetic patients and matched normal controls. The findings have been related to the presence of microangiopathy and to glycaemic control. Ascorbic acid levels were significantly lower in diabetics (mean +/- SD 42.5 +/- 26.2 mumol/l) compared with controls (58 +/- 21 mumol/l p less than 0.02). Although there was no differences in DHAA levels between the groups the ratio DHAA/AA was increased in diabetics (0.72 +/- 0.8) compared with controls (0.4 +/- 0.2 p less than 0.05). There were no significant differences between insulin and non-insulin dependent patients in these measurements and there was no association with the presence of microangiopathy or poor glycaemic control. The plasma ratio DHAA/AA may be a reflection of increased oxidative stress and our results suggest that diabetics may be less able to prevent oxidative damage occurring due to their lower AA concentrations.
最近有证据表明，糖尿病微血管病变与自由基诱导的氧化损伤增加有关。抗坏血酸（AA）是一种自由基清除剂，我们使用特定的高效液相色谱法，研究了糖尿病患者及其匹配的正常对照者体内抗坏血酸及其氧化代谢产物脱氢抗坏血酸（DHAA）的浓度。这些研究结果与微血管病变的存在以及血糖控制情况相关。与对照组（58±21μmol/L，p<0.02）相比，糖尿病患者体内的抗坏血酸水平显著降低（平均±标准差为42.5±26.2μmol/L）。尽管两组之间的DHAA水平没有差异，但糖尿病患者的DHAA/AA比值（0.72±0.8）高于对照组（0.4±0.2，p<0.05）。在这些测量中，胰岛素依赖型患者和非胰岛素依赖型患者之间没有显著差异，并且与微血管病变的存在或血糖控制不佳无关。血浆中DHAA/AA比值可能反映了氧化应激的增加，我们的研究结果表明，糖尿病患者可能由于其较低的AA浓度而较难预防氧化损伤的发生。
