糖尿病患者低密度脂蛋白亚组分颗粒大小及氧化易感性的分析

Analysis of low density lipoprotein subfraction particle size and its susceptibility to in vitro oxidation in patients with diabetes mellitus

目的 :研究糖尿病 (DM)患者低密度脂蛋白 (L DL)亚组分颗粒直径及氧化易感性的异常特征 ,探讨其动脉粥样硬化 (AS)高发生率的机制。 方法 :超速离心分离 30例 DM患者及 2 6例对照组的血浆 L DL,采用 2 %～16 %聚丙烯酰胺凝胶梯度电泳法分析 L DL 颗粒直径及图形 ,并分析其抗氧化能力。 结果 :1DM患者 L DL 颗粒直径为 (2 6 .31± 0 .72 ) nm同对照组 (2 6 .41± 0 .95 ) nm之间无差异 ,两组间 A型、B型 L DL图形亦相同。 2 L DL颗粒直径同血浆 TG水平呈负相关 (r=- 0 .32 ,P<0 .0 5 )。 3DM患者 L DL抗氧化能力下降。 结论 :DM患者 AS的高发生率与其 L DL 易于氧化的特性相关联。

Objectives: To study the size and susceptibility of low density lipoprotein (LDL) particle in patients with diabetes mellitus (DM). Methods: Plasma LDL in 30 DM patients and 26 control subjects were analyzed by 2%~16% nondenaturing polyacrylamide gradient gels, and susceptibility of LDL to Cu 2+ mediated oxidation was analyzed by continuous measurements of absorbance at 234 nm. Results: LDL particle diameters in DM patients and control subjects were (26.31±0.72)nm and (26.41±0.95)nm, they were not different significantly( P >0.05). The distribution pattern of LDL subfraction did not differ significantly. LDL particle diameter negatively correlated with plasma levels of triglycerides ( r =-0.32, P <0.05). In the absorbance test,DM patients had significantly shorter lag time than controls (56.2±23.7)min vs (97.3±41.2)min( P <0.05). Conclusions: Circulating LDL isolated from DM patients was more susceptible to oxidation in vitro than controls, which may be associated with increased risk for coronary artery disease.