The clinical study of indexes of early renal injury in hypertension patients

Objective To observe the diagnostic value of combined detection of homocysteine (Hcy), β2-microglobulin (β2-MG) and cystatin C (Cys-C) or the early renal injury in hypertension.Methods 236 cases of hypertension were enrolled to the Cardiology Department of People's Hospital of Wuhan Caidian District from October 2015 to October 2017. And 100 normal persons served as control group. Patients were divided into 3 groups:grade 1 hypertension group (140-159/90-99 mmHg), grade 2 hypertension group (160-179/100-109 mmHg) and grade 3 hypertension group (≥ 180/110 mmHg). Patients were assigned into normal groupgroup A, eGFR ≥ 90 mL·(min)^-1·(1.73 m²)^-1, mild groupgroup B, eGFR ≥ 60-89 mL·(min)^-1·(1.73 m²)^-1 and moderate+severe groupgroup C, eGFR<60 mL·(min)^-1·(1.73 m²)^-1. The relationship between the levels of Hcy, β2-MG and Cys-C with the severity of hypertension and kidney injury was observed, and the diagnostic value was verified by receiver operating characteristic (ROC) curve.Results The levels of Hcy, β2-MG and Cys-C levels were correlated with the severity of hypertension. The levels of Hcy, β2-MG and Cys-C in group C were significantly higher than those in group A, group B and control group (P<0.05). Univariate analysis revealed that there was significant difference in systolic blood pressure, diastolic blood pressure, diabetes, eGFR, Hcy, β2-MG and Cys-C between renal injury group and renal non-injury group (P<0.05 for all). ROC curve analysis indicated that the optimal cutoff of Hcy to predict the early renal injury in hypertension was 18.28 mmol/L (AUC=0.843, sensitivity 0.838, specificity 0.730), that of β2-MG was 10.75 mmol/L (AUC=0.812, sensitivity 0.804, specificity 0.770), and that of Cys-C was 1.96 mg/L (AUC=0.784, sensitivity 0.820, specificity 0.784).Conclusions It is proved that the combined detection of Hcy, β2-MG and Cys-C has a higher value in diagnosing hypertension patients with early kidney injury.