Kim K M, Kim S-S, Kim H, Koo T, Im E Y, Kim S B
Department of Internal Medicine,University of Ulsan College of Medicine, Seoul, South Korea.
Clin Nephrol. 2011 May;75(5):458-65. doi: 10.5414/cnp75458.
beta2-Microglobulin (beta2-M) has been considered a surrogate marker of putative mid-molecular weight (MW) uremic toxins, compounds difficult to dialyze by low-flux dialysis membranes. This study was performed to evaluate the relationship between serum beta2-M and survival of chronic hemodialysis (CHD) patients and the association of beta2-M levels and factors associated with mortality.
Part I of this study is a retrospective cohort evaluation that determined the relationship between beta2-M and mortality, and Part II is a cross-sectional study that evaluated the relationship between beta2-M and factors associated with mortality. Laboratory parameters, including beta2-M, albumin, prealbumin, creatinine, blood urea nitrogen (BUN), high-sensitivity C-reactive protein (hs-CRP), lipid battery, KT/V, and normalized protein nitrogen appearance (nPNA), were reviewed in Part I and measured in Part II. Clinical and demographic data, including age, sex, duration of hemodialysis, presence of cardiovascular disease, and presence of diabetes mellitus, were also recorded.
Part I: During the follow-up period of 5 years, there were 95 all-cause deaths among the 289 patients. Comparison of survivors and non-survivors indicated that serum beta2-M was higher in survivors (36.8 ± 12.3 vs. 32.6 ± 13.2 µg/ml, p = 0.009). Kaplan-Meier analysis indicated that all-cause mortality in the lower beta2-M group was significantly higher compared to the higher beta2-M group (p < 0.0001). Multivariate Cox regression analyses indicated elevated beta2-M levels were significantly associated with lower mortality rate (relative risk: 0.608; 95% CI: 0.37 to 0.99; p = 0.046). Part II: The mean serum beta2-M concentration was 37.1 ± 14.4 µg/ml. Univariate analysis indicated that beta2-M was positively correlated with nPNA, duration of HD, BMI, and the concentrations of creatinine, albumin, BUN, and hs-CRP, but was negatively correlated with HDL-C concentration. Multiple regression analysis indicated that levels of nPNA (p < 0.001), duration of hemodialysis (p < 0.001), creatinine (p < 0.001), albumin (p = 0.006), BUN (p = 0.011), and HDL-C (p = 0.038) were independently associated with serum beta2-M concentration.
Our results showed that higher serum beta2-M levels are associated with better survival in CHD patients and that nutritional status might be an independent predictor of serum beta2-M concentration in these patients.
β2微球蛋白（β2-M）被认为是假定的中分子量（MW）尿毒症毒素的替代标志物，这些化合物难以通过低通量透析膜进行透析。本研究旨在评估血清β2-M与慢性血液透析（CHD）患者生存率之间的关系，以及β2-M水平与死亡率相关因素的关联。
本研究的第一部分是一项回顾性队列评估，确定β2-M与死亡率之间的关系，第二部分是一项横断面研究，评估β2-M与死亡率相关因素之间的关系。在第一部分中回顾了实验室参数，包括β2-M、白蛋白、前白蛋白、肌酐、血尿素氮（BUN）、高敏C反应蛋白（hs-CRP）、血脂谱、KT/V和标准化蛋白氮出现率（nPNA），并在第二部分中进行了测量。还记录了临床和人口统计学数据，包括年龄、性别、血液透析持续时间、心血管疾病的存在以及糖尿病的存在。
第一部分：在5年的随访期内，289例患者中有95例全因死亡。存活者与非存活者的比较表明，存活者的血清β2-M更高（36.8±12.3对32.6±13.2μg/ml，p = 0.009）。Kaplan-Meier分析表明，较低β2-M组的全因死亡率显著高于较高β2-M组（p < 0.0001）。多变量Cox回归分析表明，β2-M水平升高与较低的死亡率显著相关（相对风险：0.608；95%CI：0.37至0.99；p = 0.046）。第二部分：血清β2-M的平均浓度为37.1±14.4μg/ml。单变量分析表明，β2-M与nPNA、血液透析持续时间、体重指数以及肌酐、白蛋白、BUN和hs-CRP的浓度呈正相关，但与高密度脂蛋白胆固醇（HDL-C）浓度呈负相关。多元回归分析表明，nPNA水平（p < 0.001）、血液透析持续时间（p < 0.001）、肌酐（p < 0.001）、白蛋白（p = 0.006）、BUN（p = 0.011）和HDL-C（p = 0.038）与血清β2-M浓度独立相关。
我们的结果表明，较高的血清β2-M水平与CHD患者更好的生存率相关联，并且营养状况可能是这些患者血清β2-M浓度的独立预测因素。
