Correlation between markers of early renal injury in urine and serum homocysteine elevation / 中华健康管理学杂志

Objective:To investigate the correlation between early renal impairment markers in urine and elevated serum homocysteine.Methods:Clinical data of serum homocysteine (Hcy) and early renal injury markers in urine of the health examination population from the Physical Examination Center of Peking University Third Hospital from January 2019 to May 2020 were retrospectively analyzed (1133 cases). The previous medical history, age, sex, blood pressure, body mass index (BMI) of the subjects were collected. Early urine kidney injury markers, including urine microalbumin (U-mALB), urinary N-acetyl-β-D-glucosaminidase (NAG), urinary albumin to creatinine ratio (UACR), and serum renal function, liver function, blood lipid, myocardial enzyme and glycosylated hemoglobin (HbA 1C), etc. were also collected. Those with incomplete previous history, general information, biochemical indexes and decreased estimated glomerular filtration rate (eGFR) were excluded, and 969 cases were included. The included subjects were divided into the normal group (?15 μmol/L) and the elevated group (≥15 μmol/L) according to Hcy levels, the indexes with significant difference between the two groups were included as independent variables, and the multivariate logistic regression was used to explore the influence factors of Hcy elevation. Results:The male ratio, the incidence of increased U-mALB, NAG and UACR were significantly higher in the elevated group than those in the normal Hcy group (93.4% vs 50.6%, 16.4% vs 8.0%, 23.0% vs 14.0%, 13.9% vs 7.9%) (all P<0.05). Systolic blood pressure, diastolic blood pressure, serum uric acid, calcium, alanine aminotransferase (ALT) and lactate dehydrogenase in the elevated group were higher than those in the normal group [(127.5±15.4) vs (121.9±16.2) mmHg (1 mmHg=0.133 kPa), (78.6±9.3) vs (76.0±11.0) mmHg, (385.9±86.0) vs (335.7±88.2) μmol/L, (2.392±0.086) vs (2.366±0.092) mmol/L, (27.8±21.0) vs (23.8±20.2) U/L, (198.3±28.4) vs (192.2±31.2) U/L] (all P<0.05), while high density lipoprotein cholesterol (HDL-C), serum phosphorus were lower than those in the normal group [(1.21±0.25) vs (1.31±0.30) mmol/L, (1.107±0.154) vs (1.158±0.159) mmol/L] (all P<0.05). The increased systolic blood pressure, male, uric acid, U-mALB, NAG were independent correlative factors of Hcy elevation. Conclusion:The increase of Hcy is independently correlated with urine U-mALB and NAG, which suggests that the level of Hcy should be detected as soon as possible in patients with elevated early renal injury markers.

Study on Combined Determination Plasma NGAL,Cys C and Urinary NAG/Crea for the Diagnosis of Early Diabetic Nephropathy / 现代检验医学杂志

Objective To investigate the value of plasma neutrophil gelatinase-associated lipocalin (NGAL),cystatin C (Cys C) and the ratio of urinary N-acetyl-beta-D-glucosaminidase to creatinine (NAG/Crea) combined determination in the diagnosis of early diabetic nephropathy.Methods Collected 67 cases of patients with type 2 diabetes hospitalized in the First Affiliated Hospital of Kunming Medical University from December 2016 to February 2017.According to the value of UALB/Crea was divided into two groups:Diabetic urinary microalbumin normal group (UALB/Crea＜30 mg/gCrea) had 35 patients and early diabetic nephropathy group (namely the trace albuminuria group,UALB/Crea 30 ～ 300 mg/gCrea) had 32 patients.Other selected 20 normal volunteers as control group,compared with a medical group to gather all the staff of the clinical data,using automatic biochemical analyzer detected the plasma NGAL,Cys C and urine NAG/Crea,and adopted the receiver-operating characteristic (ROC) curve of the detection index was analyzed.Results ①Plasma NGAL,Cys C and urinary NAG/Crea of diabetic nephropathy patients was significantly higher than those of healthy control group (Z=-5.740 ～-5.386,P＜0.05).②The areaunder receiver operating characteristic (ROC) curve of plasma NGAL,Cys C and urine NAG/Crea were 0.858,0.911 and 0.714.Conclusion Plasma NGAL,Cys C and urinary NAG/Crea combined determination have a higher value for early diagnosis of diabetic nephropathy.

Role of Urinary N-acetyl-beta-D- glucosaminidase Level in Prediction of Pathological Tubular Lesion and Prognosis in Subclinical Asymptomatic IgA Nephropathy / 대한신장학회잡지

PURPOSE: Urinary N-acetyl-beta-D-glucosaminidase (NAG) has been known to reflect the damage of proximal tubular cells in the early stages of renal disease. Recent studies have demonstrated that tubular grade predicted renal outcome better than did other histological parameters in IgA nephropathy. We evaluated the meaning of urinary NAG in relation with initial histological features and renal outcomes in early subclinical IgA nephropathy. METHODS: Among the firstly diagnosed IgA nephropathy patients from Jan 2001 to Dec 2002, 43 subjects were selected with the criteria of normal renal function and 24-h urinary protein excretion <3.5 g/day. The subjects were followed for 2 years. Pathologic lesion was graded according to HASS classification and semiquantitative scorings, from 0 to 3, were carried out for glomerular (GG), interstitial (IG), tubular (TG), and vascular (VG) lesion. RESULTS: The subjects consisted of 20 male and 23 female with mean age of 30+/-13 years, baseline blood pressure 116+/-15/74+/-10 mmHg, Cr 1.03+/-0.24 mg/dL, Ccr 88+/-19 mL/min, 24-h urinary protein excretion (UPER) 1, 790+/-1, 610 mg/24-h, urinary NAG 11.8+/-11.0 U/g cr at the time of biopsy. Hass subclass was correlated significantly with glomerular, tubular, and interstitial grades (all p<0.05). In comparison with clinical parameters, glomerular grade was significantly related with 24-h UPER (p<0.05) and tubular grade was significantly related with systolic blood pressure (p<0.05). Urinary NAG level at the time of biopsy show significant correlation with tubular grade (p<0.05). Progression of renal disease occurred in nine patients (20.9%). The patients with renal disease progression showed significantly low baseline Ccr, high 24-h UPER, and high NAG (all p<0.05). In pathological findings, tubular grade was significantly related with renal prognosis (p<0.05). In regression analysis, tubular grade was a independent predictor of renal prognosis among above four parameters showing significant differences. In survival analysis, tubular grade 0, 1 and grade 2, 3 showed significant difference in renal survival as compared to each other. The patients with baseline NAG urinary NAG above 10 U/g Cr showed significantly worse renal survival as compared with those below 10 U/g Cr (p<0.05). CONCLUSION: Tubular lesion is an independent factor associated with renal progression in these patients. Urinary NAG reflects well the degree of tubular lesion at the time of biopsy. We carefully suggest, therefore, that the measurement of urinary NAG level is helpful to estimate tubular lesion and predict renal prognosis in subclinical asymptomatic IgA nephropathy patients before they undergo renal biopsy.

Usefulness of Urinary n-acetyl-beta-d-Glucosaminidase(nag) for a Predictor of Aminoglycoside Nephrotoxicity / 대한신장학회잡지

Nephrotoxicity is a major factor limiting the clinical utility of aminoglycoside antibiotics(AG). In this study, we have therefore investigated the usefulness of the renal tubular protein for a predictor of the nephrotoxicity of AG. We have also compared the nephrotoxicity among different AG. Among the simple fracture patients visiting orthopedics, for whom an AG seemed warrantable, we have sampled thirty-nine subjects--excluding those suffering from severe bleeding, taking drugs, or having renal disease which can affect the renal function. We have set three different groups by the following criteria; ten subjects in group I were given 250mg of Amikacin sulfate twice a day; fifteen subjects in GroupII were given 60mg of Micronomicin sulfate twice a day; and fourteen subjects in GroupIII were given 200mg of Isepacin sulfate twice a day. Urine from each patient was collected for 24 hours before, one week after, and two weeks after the drugs were given, and then the urinary concentrations of NAG, beta2-Microglobulin(beta2-MG), and electrolyte(Na+, K+, Cl-) were measured. The measurement of 24-hour urinary concentrations of NAG shows that, for all three groups, significant increase of the concentrations(P<0.01) is seen between the different times in the same group. The results of measurements of the 24-hour urinary concentrations of beta2-MG, and electrolyte(Na+, Ke+, Cl-) show their increase for all three groups but whithin the normal range. For the samples collected two weeks after the drugs were given, there is a significant decrease in the twenty-four-hour urinary concentrations of NAG(P<0.05) of Group III compared to Group I and II. The resulta of measurements of 24-urinary concentrations of beta2-MG, and electrolyte(Na+, K+, Cl-) show their increase for all three groups but whithin the normal range. In conclusion, we have seen that the nephrotoxicity of the AG appears for all three groups; but, when we compare the nephrotoxicity between the different antibiotics, the nephrotoxicity of Amikacin sulfate and that of Micronomicin sulfate appear stronger than that of Isepacin sulfate. Our data suggest the usefulness of sequential NAG measurements in monitoring and predicting aminoglycoside nephrotoxicity.

A Study on Urinary N-acetyl-beta-D-glucosaminidase Activities of Office Workers in a Certain Industrial Complex Area / 예방의학회지

In order to identify the necessary information of biochemical indices for renal effect of lead for the early detection in medical surveillance of lead worker, the reference values of urinary N-acetyl-beta-D-glucosaminidase(NAG) activities were studied with 205 office workers in one industrial complex area who were not exposed to lead occupationally. While study variables selected for lead exposure were blood lead (pbB), blood zinc protoporphyrin(ZPP) and delta-aminolevulinic acid (DALA) in urine, those for renal effect were urinary N-acetyl-beta-D-glucosaminidase(NAG), blood urea nitrogen(BUN), serum creatinine(cr), serum uric acid (Ua), and urinary total protein (U-Tp). The results obtained were as follows: 1. The mean values of blood lead, ZPP and DALA in all subjects were 14.39+/-4.02 microgram/dl, 21.61+/-8.00 microgram/dl, and 2.73+/-0.90 microgram/l respectively. 2. The mean value of urinary NAG activities in all subjects was 3.51+/-2.01 U/l. The mean value of urinary NAG activities, which calculated from NAG activities divided by urinary creatinine concentration (CNAG), was 5.42+/-5.53 U/g creatinine and logarithmic normal distributed. 3. The reference value of urinary NAG activity was 12.06 U/g creatinine (95% CI=10.57-14.76U/g creatinine). 4. Logarithmic CNAG(r=0.781 P<0.01), U-TP(r=0.670 p<0.01) and ZPP (r=0.172 p<0.05)showed statistically significant correlation with CNAG.