Relationship of Urinary Protein Level with Serum Cystatin C, β_2-microglobulin and Urinary Albumin/creatinine Ratio in Patients with Diabetic Nephropathy

Objective To study the relationship of urinary protein level with serum Cys C, β2-MG and urinary UmAlb/UCr ratio in patients with diabetic nephropathy(DN). Methods The DN patients were divided into three phases according to 24-hour urinary albumin excretion rate(UAE) which recognized diagnostic indicator for diabetes mellitus complicated with DN, group A[n=52, in phaseⅠwith normoalbumin(UAE30 mg/24 h)], group B [n=35, in phase Ⅱ with microalbumin(30 mg/24 h≤UAE300 mg/24 h)] and group C[n=21, in phase Ⅲ with macroalbumin(UAE≥300 mg/24 h)]; 50 cases of healthy controls were collected. The levels of serum CysC, β2-MG and urinary UmAlb/UCr of all subjects were detected. Results Compared with the healthy control group, the levels of serum CysC, β2-MG of group A, group B and group C were significantly increased(P0.01). Compared between three patient groups, the differences of all items were all significant between groups, and group Cgroup Bgroup A(P0.01); the levels of serum CysC, β2-MG and urinary UmAlb/UCr increased with the increasing clinical phases and the correlation coefficients of serum CysC, β2-MG and urinary UmAlb/Ucr with the UAE were 0.486, 0.536 and 0.858, respectively(P0.01). Conclusion The levels of serum CysC, β2-MG and urinary UmAlb/Ucr are closely related with the level of urinary protein in patients with diabetic nephropathy. As development of the degree of urinary protein, the level of serum CysC, β2-MG and urine UmAlb/UCr increase.