Diagnosis value of urinary type Ⅳ collagen, NAG and serum CysC,β2-MG for diabetic nephropathy / 中国综合临床

ABSTRACT

Objective To compare the efficacy of urinary type Ⅳ collagen( Ⅳ C), N-acetyl-β-D-glucosaminidase( NAG ), serum cystatin C ( CysC ), β2 microglobulin ( β2-MG ) in early diagnosis of diabetic nephropathy(DN) ,and to develop a multiple regression equation using above mentioned indices. Methods One hundred and eight cases of DM patients were enrolled in the study. All those DM patients were divided into two groups according to 24 hr urinary albumin excretion(UAE): non-DN group( UAE ＜30 mg/24 h)and DN group (UAE ≥30 mg/24 h). Receiver operating characteristics (ROC)curve was developed using urinary IVC, NAG,serum CysC and β2-MG,and the efficiency of the four indices for early diagnosis of diabetic nephropathy were assessed by area under the curve ROC (AUCROC). Furthermore, the regression equation of four indicators was developed. All statistical analyses were performed using SPSS 13.0. Results The levels of urine Ⅳ C, NAG,CysC,β2-MG,were(3.91±1.93)ng/ml, ( 12.20 ±3.46)U/L, ( 1.18 ±0.41 )mg/L , (2. 50 ±0. 74)mg/ml in the non-DN group, respectively; and ( 14.14 ± 11.17 ) ng/ml, ( 23.12 ± 13.57 ) U/L, ( 2.69 ± 1.69 ) mg/L and(5.21 ± 2.78)mg/ml in the DN group, respectively. There were significant differences in the comparison of the four indicators between the two groups ( Ps ＜ 0.01 ). AUCROC of Ⅳ C, NAG, CysC and β2-MG were 0. 747,0.732,0.764 and 0.823 respectively;which meant the diagnostic efficacy for DN decended from β2-MG, CysC,Ⅳ C, to NAG in order. All these indices showed significant efficiency in assisting diagnosis of early DN ( Ps ＜0.01 ). The regression equation of UAE and the four indices was: UAE = - 242.624 + 6.362IVC + 8.662NAG + 64. 622CysC + 29.488β2-MG, and the equation had statisticl significance( P ＜ 0.O1 ). Conclusion Urine Ⅳ C, NAG,serum CysC, and β2-MG showed significant value in assisting diagosis of early DN, and could be sensitive indices for DN.