Karabina Sonia Athena, Pappas Haralampos, Miltiadous George, Bairaktari Eleni, Christides Dimitris, Tselepis Alexandros, Elisaf Moses, Siamopoulos Konstantinos
Department of Chemistry, Laboratory of Biochemistry, Medical School, University of Ioannina, Ioannina, Greece.
Nephron Clin Pract. 2003;95(3):c77-83. doi: 10.1159/000074320.
There are limited data regarding qualitative lipoprotein abnormalities in undialysed uremic patients without proteinuria. In this report, we focused on lipoprotein changes observed in uremic patients with proteinuria as well as on the susceptibility of low-density lipoprotein (LDL) of these patients to oxidative modification in vitro.
20 patients with chronic renal failure [serum creatinine >1.6 mg/dl (141.4 micromol/l)], but not yet on renal replacement therapy, and with heavy proteinuria (>2 g/24 h), and 18 age- and sex-matched healthy individuals participated in the study. In both patients and controls, venous blood was collected for determination of serum lipid and lipoprotein levels, lipoprotein subfraction profile and chemical composition, as well as the susceptibility of LDL subfractions to oxidation.
Patients exhibited a more atherogenic lipid profile compared with the control population. Furthermore, the total very LDL + intermediate-density lipoprotein mass was increased in patients compared with controls, while this subfraction was triglyceride enriched in uremic patients. The total LDL concentration was significantly higher in patients compared with controls due mainly to an increase in the mass of all lipoprotein subfractions. It is noteworthy that the mass of small dense LDL was significantly elevated in patients compared with controls (135 +/- 12 vs. 115 +/- 11 mg/dl, p = 0.01), an increase which was more pronounced in hypertriglyceridemic patients. Furthermore, the subfraction high-density lipoprotein-2 mass was significantly lower in uremic patients compared with controls. Finally, no significant differences in the lag time, the rate of oxidation and the relative electrophoretic mobility values in each LDL subfraction between the two groups were observed.
We conclude that uremic patients with heavy proteinuria exhibit compositional lipoprotein changes that are less marked than those observed in nonuremic patients with nephrotic syndrome. However, there is no evidence that circulating LDL isolated from these patients is more susceptible to oxidation in vitro than lipoprotein isolated from age- and gender-matched controls.
关于未透析的无蛋白尿尿毒症患者定性脂蛋白异常的数据有限。在本报告中，我们重点关注了蛋白尿性尿毒症患者中观察到的脂蛋白变化，以及这些患者的低密度脂蛋白（LDL）在体外对氧化修饰的易感性。
20例慢性肾衰竭患者[血清肌酐>1.6mg/dl（141.4μmol/l）]，尚未接受肾脏替代治疗，且有大量蛋白尿（>2g/24h），以及18名年龄和性别匹配的健康个体参与了本研究。在患者和对照组中，均采集静脉血以测定血脂和脂蛋白水平、脂蛋白亚组分谱和化学组成，以及LDL亚组分的氧化易感性。
与对照组相比，患者表现出更具动脉粥样硬化性的血脂谱。此外，与对照组相比，患者的极低密度脂蛋白（VLDL）+中间密度脂蛋白（IDL）总量增加，而该亚组分在尿毒症患者中富含甘油三酯。患者的总LDL浓度显著高于对照组，主要是由于所有脂蛋白亚组分的质量增加。值得注意的是，与对照组相比，患者的小而密LDL质量显著升高（135±12 vs. 115±11mg/dl，p=0.01），在高甘油三酯血症患者中这种增加更为明显。此外，与对照组相比，尿毒症患者的高密度脂蛋白2（HDL-2）亚组分质量显著降低。最后，两组之间各LDL亚组分的延迟时间、氧化速率和相对电泳迁移率值均未观察到显著差异。
我们得出结论，大量蛋白尿的尿毒症患者表现出的脂蛋白组成变化不如非尿毒症肾病综合征患者明显。然而，没有证据表明从这些患者中分离出的循环LDL在体外比从年龄和性别匹配的对照组中分离出的脂蛋白更容易被氧化。
