老年糖尿病患者自由基与微血管并发症关系的探讨

Relationship between free radicals and microvascular complications in elderly patients with type 2 diabetes mellitus

目的 探讨老年糖尿病患者自由基和抗氧化能力的变化及其与微血管并发症的关系。 方法 测定 6 5例老年糖尿病患者和 6 5例健康老年对照者血浆或红细胞中脂质过氧化物 (LPO)、超氧化物岐化酶 (SOD)、过氧化氢酶 (CAT)、谷胱甘肽过氧化物酶 (GSH PX)、维生素C(VC)、维生素E(VE)、β 胡萝卜素 (β CAR)、谷胱甘肽 (GSH) ,同时测定患者的空腹血糖、餐后 2h血糖、糖化血红蛋白(HbA1c)、空腹和餐后 2hC肽、血脂、尿微量白蛋白排泄率、肌电图。 结果 老年糖尿病患者LPO(42 97± 6 99)nmol/g高于健康老年组 (31 5 9± 7 4 4 )nmol/g ,SOD(1712 4 4± 15 7 0 4 )U/L、CAT(2 17 0 1± 2 9 36 ) μg/g、GSH PX(2 1 0 1± 3 38)× 10 -10 U/RBC、VC(40 98± 10 5 1) μmol/L、VE(16 4 4± 2 4 5 ) μmol/L、β CAR(1 19± 0 2 3) μmol/L、GSH(0 98± 0 16 )nmol/L低于健康老年组〔分别为 (192 8 38± 14 3 4 4 )U/L、(2 6 4 4 0± 6 3 5 5 ) μg/g、(2 5 16± 6 4 1)× 10 -10 U/RBC、(5 2 2 3± 10 5 1) μmol/L、(2 3 0 4± 5 38) μmol/L、(1 6 3± 0 4 0 ) μmol/L、(1 2 5± 0 2 0 )nmol/L〕 ,合并糖尿病微血管并发症者变化更加明显 ,LPO和年龄呈正相关 (r=0 310 ,P <0 0 5 ) ,SOD。

Objective To investigate the plasma level of free radicals and antioxidative activity in elderly patients with type 2 diabetes mellitus and relation to microvascular complication. Methods The concentration of erythrocyte lipoperoxides(LPO), plasma vitamin E(VE), plasma vitamin C(VC), plasma betacarotene(β CAR), whole blood glutathione(GSH) and the activity of erythrocyte superoxide dismutase(SOD), erythrocyte catalase (CAT), erythrocyte glutathione peroxidase(GSH PX) in 65 elderly patients with type 2 diabetes and 65 healthy patients were measured. Meanwhile, fasting glucose, 2 hours post meal glucose, glycated hemoglobin, fasting and post meal C peptide, triglycerides, cholesterol, urine albumin excretion rate, electromyogram were measured. Results Compared with the healthy patients, the average value of LPO(42 97±6 99)nmol/g and (31 59±7 44)nmol/g, VC (40 98±10 51)μmol/L and (52 23±10 51)μmol/L, VE (16 44±2 45)μmol/L and (23 04±5 38)μmol/L, β CAR (1 19±0 23)μmol/L and (1 63±0 40)μmol/L and GSH(0 98±0 16 vs 1 25±0 20) in elderly patients with type 2 diabetes were significantly increased, while the activities of SOD(1712 44±157 04)U/L and (1 928 38±143 44)U/L, CAT(217 01±29 36)μg/g vs (264 40±63 55)μg/g, GSH PX(21 01±3 38)×10 -10 U/RBC vs (25 16±6 41)×10 -10 U/RBC were obviously decreased. The change was more obvious in the patients with microvascular complication compared with those without microvascular complication. Plasma level of LPO were correlated positively with age(r=0 310, P <0 05), SOD, CAT, GSH PX, VC, β CAR were correlated negatively with age( r =0 310-0 315, P <0 001) and HbA1c( r =0 265-0 498, P <0 05). Conclusions In elderly patients with type 2 diabetes, the level of LPO were increased and antioxidative activity were decreased, such change may be related to diabetic microvascular complication.