Diagnostic Value Of Urinary ?₂-MG,NAG,RBP In Early Hypertensive Nephropathy

BackgroundEssential hypertension is a multi-gene genetic disease,caused both by genetic and environmental factors,and is one of the most important risk factors for cardiovascular and cerebrovascular diseases.Kidney is a major organ contributing to hypertension,which in turn can damage kidney function.The latest study shows that the incidence of hypertensive renal complications was 42%;in 10% of the incidence,patients died of chronic renal failure,second only to heart failure.Patients usually have suffered from hypertension for 15 to 20 years before kidney,heart,or brain damage happens.However,compared to heart and brain damage,kidney damage have lower incidence and less noticeable symptoms,thus is most likely to be ignored.Due to the lack of clinical manifestations and the fact that related laboratory tests are often negative,accurate diagnosis of early hypertensive nephropathy is very challenging.When the disease is eventually confirmed,the kidney has been irreversibly damaged and the best treatment window is far gone.Therefore,early diagnosis is very important for the treatment of hypertensive nephropathy.ObjectiveTo evaluate the value of combined testing of urinary ?2-microglobulin(?2-MG),retinol binding protein(RBP),N-acetyl-?-D-glucosaminidase(NAG)for early hypertensive renal damage diagnosis by investigating the concentration changes of the three elements in patient urine.MethodsThe objects of this study are four groups of patients admitted to Luohe Central Hospital from September 2015 to August 2016.Patients in the first three groups werediagnosed so based on the diagnostic criteria of WHO.The four groups are:Hypertensive nephropathy group: 40 patients(21 males and 19 females,average 49 years old)with renal damage caused by essential hypertension.Hypertension group without nephropathy: 35 primary hypertension patients(18males and 17 females,average 57 years old)without renal impairment.Other nephropathy group: 37 patients(21 males and 16 females,average 44 years old)with renal damage caused by other reasons(25 with renal glomerular disease,and12 with tubular diseases).Control group: 54 healthy patients without hypertension,heart,kidney,brain abnormalities,diabetes,and other diseases(38 males and 16 females,average 44 years old).Urine beta 2-MG and urine RBP were detected by immune turbidity method,and urine NAG was detected by continuous monitoring method.All data are analyzed with SPSS-16 software.The results are expressed as ` x ± s,variance analysis were compared among multiple groups,statistical difference were compared with Dunnett's T3.P <0.05 means the difference is statistically significant.The ROC curves were drawn using the sensitivity and specificity of ?2-MG,NAG and RBP.ROC curve was used to evaluate the diagnostic efficacy of the three indictors(urinary NAG??2-MG?RBP)in early hypertensive nephropathy diagnosis.Results1.The concentration and positive rate of urinary NAG,?2-MG,RBP in hypertensive nephropathy group,hypertension group without nephropathy and other nephropathy group were significantly higher(P < 0.01)than those in control group.2.ROC and the area under the curve(AUC)were used to determine the sensitivity and specificity.ROC analysis between control group and hypertensive nephropathy group showed that NAG < RBP < ?2-MG in terms of area under the ROC curve(AUC).Among the three indicators,as the one with highest Youden index,?2-MG had80% diagnostic sensitivity,94.4% specificity,and it diagnostic critical value is 0.67mg/L.3.ROC and the area under the curve(AUC)were used to determine the sensitivity and specificity.ROC analysis between control group and hypertension group without nephropathy showed that RBP<NAG<?2-MG in terms of area under the ROC curve(AUC).Among the three indicators,as the one with highest Youden index,?2-MG had 65.7% diagnostic sensitivity,98.1% specificity,and it diagnostic critical value is0.835 mg/L.4.ROC and the area under the curve(AUC)were used to determine the sensitivity and specificity.ROC analysis between control group and other nephropathy group showed that ?2-MG < RBP <NAG in terms of area under the ROC curve(AUC).Among the three indicators,as the one with highest Youden index,NAG had 81.1%diagnostic sensitivity,92.6% specificity,and it diagnostic critical value is 10.1 U/L.ConclusionUrinary ?2-MG,RBP,NAG are sensitive indicators of early renal damage in patients with hypertensive nephropathy,therefore combined testing is valuable to estimate the degree of renal function damage.