2型糖尿病肾病患者血清总胆红素水平与胱抑素C的相关性

Correlation between serum total bilirubin level and cystatin-c in patients with type 2 diabetic nephropathy

目的探讨2型糖尿病肾病(DN)患者血清总胆红素(TBIL)水平与胱抑素C(Cys-c)之间的关系。方法选择561例T2DM患者,根据尿微量白蛋白/肌酐比值(UACR)分为单纯糖尿病组(NAU组,232例)、微量白蛋白尿组(MAU组,211例)和大量蛋白尿组MAAU组,118例),采用酶法测定血清TBIL水平并比较,分析TBIL与Cys-c、预估肾小球滤过率(eGFR)、UACR、血糖、血脂、血压等指标的关系。同时将所有研究对象以TBIL上四分位为切点分为A组与B组,比较两组间DN的患者比例及Cys-c等肾功能指标的变化趋势。Binary logistic回归法分析T2DM患者发生肾病的危险因素。结果 MAAU组和MAU组血清TBIL水平明显低于NAU组(9.26±3.28 vs.10.69±3.66 vs.11.97±3.78μmol/L,均P<0.01),MAAU组血清TBIL水平明显低于MAU组(9.26±3.28 vs.10.69±3.66μmol/L,P<0.01)。相关分析显示,T2DM患者血清TBIL与BMI、HDL-C、apoA、DBIL、IBIL和eGFR呈正相关,与Cys-c、Scr﹑UACR、WBC和RDW呈负相关(P<0.05或P<0.01)。校正性别、年龄和BMI后,T2DM患者TBIL与Cys-c仍呈明显负相关(P<0.01)。多元逐步回归分析显示,Cys-c、BMI和WBC是影响T2DM患者血清TBIL水平的独立相关因素。B组Scr、Cys-c、UACR、DN患者比例和MAAU患者比例均明显高于A组(P均<0.01)。Logistic回归分析显示,Cys-c、年龄和WBC是预测T2DM患者DN发病的独立危险因素,TBIL是预测T2DM患者DN发病的独立保护因素(P<0.05或P<0.01)。结论早期DN患者血清TBIL水平较单纯T2DM患者明显下降,随着UACR增加,血清TBIL水平逐渐下降,且与血清Cys-c水平密切相关。

Objective To investigate the relationship between serum total bilirubin （TBIL） level and cystatin- C （Cys-c） in patients with type 2 diabetic nephropathy （DN）. Methods diabetes mellitus （T2DM） into 3 groups., normo-albuminuria group （NAU We divided 561 patients with type 2 group, 232 cases）, microalbuminuria group （MAU group, 211 cases）, and macroalbumnuria group （MAAU group, 118 cases） according to urine microalbuminuria-to-creatinine ratio （UACR）. Fasting serum TBIL levels were measured by enzymatic method and compared. We also analyzed the relationship of TBIL with such parameters as Cys-c, estimated glomerular filtration rate （eGFR）, UACR, blood glucose, blood lipid, and blood pressure. All T2DM patients were divided into A and B groups according to the upper quartile of TBIL; the proportion of DN and Cys-c trend in the two groups was compared.Risk factors of DN in T2DM patients were analyzed by binary logistic regression analysis. Results Serum TBIL levels were significantly lower in MAAU and MAU groups than in NAU group （9.26±3; 28 vs. 10. 69±3.66 vs. 11. 97±3.78 μmol/L, all P〈0.01）. Serum Cys-c level was significantly lower in MAAU group than in MAU group （9.26±3.28 vs. 10.69±3.66 μmol/L, P〈0.01）. Correlation analysis showed that serum TBIL level was positively correlated with body mass index （BMI）, high-density lipoprotein cholesterol （HDL-C）, apolipoprotein A （apoA）, direct bilirubin （DBIL）, indirect bilirubin （IBIL） and eGFR, but negatively correlated with Cys-c, serum creatinine （Scr） , UACR, white blood cell （WBC） and red distribution width （RDW） （P〈0.05 or P〈0.01）. Serum TBIL level in T2DM patients was positively correlated with Cys-c after adjusting for gender, age and BMI （P〈0.01）. Multiple regression analysis revealed that Cys-c, BMI and WBC were independent related factors influencing TBIL level in T2DM patients. Compared with those of A group, the levels of Scr, Cys-c and UACR and proportion of DN and MAAU increased in B group （all P〈0. 01）. Binary logistic regression analysis found that Cys-c, age and WBC were independent risk factors for predicting DN in T2DM patients, and TBIL was an independent protective factor for predicting DN in T2DM patients （P〈0.05 or P〈0.01）. Conclusion Serum TBIL level in early DN patients decreased compared with that in T2DM patients with normo-albuminuria. With the increase of UACR, serum TBIL level gradually reduced, which was closely related to serum Cys-c level.