Heimbürger O, Stenvinkel P, Berglund L, Tranoeus A, Lindholm B
Department of Renal Medicine, Karolinska Institute, Huddinge University Hospital, Sweden.
Nephron. 1996;72(2):135-44. doi: 10.1159/000188831.
Markedly increased plasma lipoprotein(a) [Lp(a)] levels have recently been reported in continuous ambulatory peritoneal dialysis (CAPD) patients but the genesis is obscure. Lp(a) levels in CAPD are in general higher than in hemodialysis (HD) patients, suggesting that the dialysis procedure might be of importance. In the present study, we investigated relationships between Lp(a) and parameters related to the dialysis procedure per se (dialysis dose, peritoneal glucose absorption, protein losses and protein clearances) in 32 adult CAPD patients. Uremic patients treated with HD (n = 73) as well as a group of 43 healthy subjects served as control groups. The plasma level of Lp(a) was significantly higher in the CAPD patients (median 28.2 mg/dl) than in the HD patients (median 9.2 mg/dl) and the healthy controls (median 7.0 mg/dl), whereas Lp(a) levels in the HD patients did not differ from the healthy controls. In the CAPD patients, significant correlations were found between Lp(a) and 24-hour peritoneal and total clearance for albumin (r = 0.472 and r = 0.368, p < 0.01 and p < 0.05, respectively), and between Lp(a) and 24-hour peritoneal clearance for beta(2)-microglobulin (r = 0.421; p < 0.05). Similar correlations were found between Lp(a) and 24-hour peritoneal albumin excretion, total albumin excretion and peritoneal beta(2)-microglobulin excretion. Furthermore, a significant correlation was found between Lp(a) and peritoneal glucose absorption (r = 0.352; p < 0.05). Serum cholesterol showed significant correlations with 24-hour .peritoneal albumin loss and 24-hour peritoneal beta(2)-microglobulin clearance, whereas LDL cholesterol showed a significant correlation with 24-hour peritoneal beta(2)-microglobulin clearance. In a longitudinal study of 12 CAPD patients, Lp(a) levels increased significantly between the start of CAPD and at follow-up 3-5 months later. The correlation of the markedly increased levels of Lp(a) with peritoneal albumin and beta(2)-microglobulin clearance suggests that the mechanism behind the increased Lp(a) levels may be related to the large protein losses in CAPD, perhaps via an increased synthesis rate of apolipoprotein (a) in the liver or via decreased Lp(a) catabolism in CAPD patients. Finally, the correlation between Lp(a) and peritoneal glucose absorption also indicates that the increased plasma Lp(a) levels in CAPD are related to the dialysis procedure, in particular peritoneal transport of proteins and glucose.
最近有报道称，持续非卧床腹膜透析（CAPD）患者的血浆脂蛋白(a) [Lp(a)] 水平显著升高，但其成因尚不清楚。CAPD患者的Lp(a)水平总体上高于血液透析（HD）患者，这表明透析过程可能很重要。在本研究中，我们调查了32例成年CAPD患者中Lp(a)与透析过程本身相关参数（透析剂量、腹膜葡萄糖吸收、蛋白质丢失和蛋白质清除率）之间的关系。以接受HD治疗的尿毒症患者（n = 73）以及43名健康受试者作为对照组。CAPD患者的血浆Lp(a)水平（中位数28.2mg/dl）显著高于HD患者（中位数9.2mg/dl）和健康对照组（中位数7.0mg/dl），而HD患者的Lp(a)水平与健康对照组无差异。在CAPD患者中，发现Lp(a)与白蛋白的24小时腹膜清除率和总清除率之间存在显著相关性（r = 0.472和r = 0.368，p分别<0.01和p<0.05），以及Lp(a)与β2-微球蛋白的24小时腹膜清除率之间存在显著相关性（r = 0.421；p<0.05）。在Lp(a)与24小时腹膜白蛋白排泄、总白蛋白排泄和腹膜β2-微球蛋白排泄之间也发现了类似的相关性。此外，发现Lp(a)与腹膜葡萄糖吸收之间存在显著相关性（r = 0.352；p<0.05）。血清胆固醇与24小时腹膜白蛋白丢失和24小时腹膜β2-微球蛋白清除率显著相关，而低密度脂蛋白胆固醇与24小时腹膜β2-微球蛋白清除率显著相关。在对12例CAPD患者的纵向研究中，CAPD开始时与3至5个月后的随访之间，Lp(a)水平显著升高。Lp(a)水平显著升高与腹膜白蛋白和β2-微球蛋白清除率之间的相关性表明，Lp(a)水平升高背后的机制可能与CAPD中大量蛋白质丢失有关，可能是通过肝脏中载脂蛋白(a)合成率增加或CAPD患者中Lp(a)分解代谢降低。最后，Lp(a)与腹膜葡萄糖吸收之间的相关性还表明，CAPD中血浆Lp(a)水平升高与透析过程有关，特别是蛋白质和葡萄糖的腹膜转运。
