The importance of serum cystatin C in the early diagnosis of hypertensive nephropathy

Objective To study the importance of serum cystatin(Cys)C in the early diagnosis of hypertensive nephropathy.Methods To test serum CysC—detected by immune transmission turbidity method,serum creatinine(CREA)and blood urea nitrogen(BUN)—determined by enzyme method,in patients with hypertension and healthy volunteers(n=305 and 330,respectively).Results The positive rate of serum CysC(55.1%)was significantly higher than that of serum CREA(8.7%)or BUN(42.3%)(P0.01)in patients with hypertension.Patients with serum CysC slightly increased(group A)had higher serum CysC positive rate than that of serum CREA and BUN(P0.01).There was no statistical significance(P0.05) between serum CysC and CREA or BUN in patients with serum CysC moderately and severely increased(group B and C,respectively).Patients have grade 1 hypertendion had higher level of serum CysC than normal control(P0.01),while only patients with grade 2 and 3hypertension could be tested having higher CREA and BUN.Conclusion Serum CysC increases much earlier than CREA and BUN in patients with hypertension.It is more sensitive and special and has more marked clinic value using CysC to diagnose early-phase hypertensive.