Prediction of End-Stage Kidney Disease Using Estimated Glomerular Filtration Rate With and Without Race : A Prospective Cohort Study.

BACKGROUND: New estimated glomerular filtration rate (eGFR) equations removed race adjustment, but the impact of its removal on prediction of end-stage kidney disease (ESKD) is unknown. OBJECTIVE: To compare the ESKD prediction performance of different eGFR equations. DESIGN: Observational, prospective cohort study. SETTING: 7 U.S. clinical centers. PARTICIPANTS: 3873 participants with chronic kidney disease (CKD) from the CRIC (Chronic Renal Insufficiency Cohort) Study contributing 13 902 two-year risk periods. MEASUREMENTS: ESKD was defined as initiation of dialysis or transplantation. eGFR was calculated using 5 Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations based on serum creatinine and/or cystatin C, with or without race adjustment. The predicted 2-year risk for ESKD was calculated using the 4-variable Kidney Failure Risk Equation (KFRE). We evaluated the prediction performance of eGFR equations and the KFRE score using discrimination and calibration analyses. RESULTS: During a maximum 16 years of follow-up, 856 participants developed ESKD. Across all eGFR equations, the KFRE score was superior for predicting 2-year incidence of ESKD compared with eGFR alone (area under the curve ranges, 0.945 to 0.954 vs. 0.900 to 0.927). Prediction performance of KFRE scores using different eGFR equations was similar, but the creatinine equation without race adjustment improved calibration among Black participants. Among all participants, compared with an eGFR less than 20 mL/min/1.73 m2, a KFRE score greater than 20% had similar specificity for predicting 2-year ESKD risk (ranges, 0.94 to 0.97 vs. 0.95 to 0.98) but higher sensitivity (ranges, 0.68 to 0.78 vs. 0.42 to 0.66). LIMITATION: Data are solely from the United States. CONCLUSION: The KFRE score better predicts 2-year risk for ESKD compared with eGFR alone, regardless of race adjustment. The creatinine equation with age and sex may improve calibration among Black patients. A KFRE score greater than 20% showed high specificity and sensitivity for predicting 2-year risk for ESKD. PRIMARY FUNDING SOURCE: National Institutes of Health.

Can Urinary KIM-1 and NGAL Predict Management Endoscopic Surgery in Acute Unilateral Obstructive Stone Disease? Results from a Prospective Cohort Study.

INTRODUCTION: Kidney injury molecule-1 (KIM-1) and neutrophil gelatinase-associated lipocalin (NGAL) are the leading novel biomarkers used efficiently in acute kidney injury (AKI). The levels of these biomarkers increase especially in the early period of nephrotoxic and ischemic renal damage. In this study, we aimed to investigate the clinical importance of NGAL and KIM-1 biomarkers used in the effective evaluation of kidney functions in patients with acute unilateral obstructive stone disease (AUOSD) in the management of endoscopic surgery. MATERIALS AND METHODS: We prospectively included patients who underwent endoscopic surgery due to AUOSD between January 2018 and December 2019. Urine KIM-1 and NGAL values of the patients were measured preoperative period, postoperative 4th h, and postoperative 7th day. The patients were evaluated according to the location and size of the stone, the degree of renal hydronephrosis, the duration of the operation, complications, and JJ stent placement. RESULTS: The study enrolled 50 patients. Urinary KIM-1/Cr and urinary NGAL/Cr ratios were higher in postoperative 4th h than in others (p < 0.001). Also, we found that urinary KIM-1/Cr and urinary NGAL/Cr ratios with Grade 2 and higher hydronephrosis were statistically higher than Grade 0-1 hydronephrosis (p < 0.001 and p: 0.042, respectively). Additionally, a preoperative urinary KIM-1 value of 1.24 ng/mL had a sensitivity of 78% and a specificity of 63% to predict the presence of hydronephrosis. When urine KIM-1 and NGAL results were compared with surgery time, stone size and location, serum creatinine (sCr) value, and Post-Ureteroscopic Lesion Scale grade, the difference was not statistically significant. Postoperative 7th day NGAL/Cr and KIM-1/Cr ratios were statistically higher in those with JJ stents placed (p: 0.03 and p: 0.004, respectively). CONCLUSION: KIM-1 and NGAL can be used in our assessment of renal function in patients with AUOSD, even if sCr is normal. Also, these biomarkers can predict the presence of hydronephrosis. It can be helpful in determining the time of surgical treatment, as well as providing information in the follow-up of patients with JJ stents after treatment.

Diagnostic utility of protein to creatinine ratio (P/C ratio) in spot urine sample within routine clinical practice.

The spot (random) urine protein to creatinine ratio (P/C ratio) is an alternative, fast and simple method of detecting and estimating the quantitative assessment of proteinuria. The aim of the work was to review the literature concerning the usefulness of spot urine P/C ratio evaluation in the diagnosis of proteinuria in the course of kidney disease, hypertension, gestational hypertension, preeclampsia, immunological diseases, diabetes mellitus, and multiple myeloma, and in the diagnosis of proteinuria in children. We searched the PubMed and Google Scholar databases using the following keywords: proteinuria, spot urine protein to creatinine ratio, spot urine P/C ratio, protein creatinine index, PCR (protein to creatinine ratio), P/C ratio and methods, Jaffe versus enzymatic creatinine methods, urine protein methods, spot urine protein to creatinine ratio versus ACR (albumin to creatinine ratio), proteinuria versus albuminuria, limitations of the P/C ratio. More weight was given to the articles published in the last 10-20 years. A spot urine P/C ratio >20 mg/mmol (0.2 mg/mg) is the most commonly reported cutoff value for detecting proteinuria, while a P/C ratio value >350 mg/mmol (3.5 mg/mg) confirms nephrotic proteinuria. The International Society for the Study of Hypertension in Pregnancy recommends a P/C ratio of 30 mg/mmol (0.3 mg/mg) for the classification of proteinuria in pregnant women at risk of preeclampsia. A high degree of correlation was observed between P/C ratio values and the protein concentration in 24-h urine collections. The spot urine P/C ratio is a quick and reliable test that can eliminate the need for a daily 24-h urine collection. However, in doubtful situations, it is still recommended to assess proteinuria in a 24-h urine collection. The literature review indicates the usefulness of the spot P/C ratio in various disease states; therefore, this test should be available in every laboratory. However, the challenge for the primary care physician is to know the limitations of the methods used to determine the protein and creatinine concentrations that are used to calculate the P/C ratio. Moreover, the P/C ratio cutoff used should be determined in individual laboratories because it depends on the patient population and the laboratory methodologies.

Evaluation of renal function in the elderly, not as easy as it seems: a review.

In the elderly assessment of renal function by glomerular filtration rate estimation is crucial for diagnostic, therapeutic and prognostic purposes. Our aim is to illustrate the different formulas available and their respective advantages and disadvantages.

Can a structured questionnaire identify patients with reduced renal function?

OBJECTIVES: To evaluate a structured questionnaire in identifying outpatients with renal dysfunction before MRI or CT in various age groups. METHODS: All patients completed a questionnaire with five risk factors indicating renal dysfunction: renal disease, renal surgery, hypertension, gout and diabetes. Serum creatinine determined by the point-of-care (POC) technique and estimated glomerular filtration (eGFR) rate was calculated using CKD-EPI equation. RESULTS: A total of 1,467 patients were enrolled. Thirty-four patients (2%) had an eGFR <30 ml/min/1.73 m(2) and 123 (8%) had an eGFR <45 ml/min/1.73 m(2). Among 55% of the 1,467 patients reporting at least one risk factor, 30 (4%) had an eGFR <30 ml/min/1.73 m(2) and 105 (13%) had an eGFR <45 ml/min/1.73 m(2). Among 651 patients not reporting a risk factor, 4 (0.6%) had an eGFR <30 ml/min/1.73 m(2) and 18 (3%) had an eGFR <45 ml/min/1.73 m(2). All four patients were >70 years old, and 12 of the 18 patients were >70 years old. CONCLUSION: The questionnaire used in patients <70 years old and determination of eGFR in patients >70 years old identified all patients with an eGFR between 30 and 45 ml/min/1.73 m(2) except 0.4%. KEY POINTS: • A questionnaire can adequately identify patients under 70 with renal dysfunction • 8% of patients referred to CT/MRI have an eGFR <45 ml/min/1.73 m (2) • 55% reported risk factors, but renal dysfunction was only found in 13% • Patients over 70 years should have eGFR determined before CT • eGFR determination is not beneficial when stable MRI agents are used.

Acute kidney injury patterns in acute heart failure: The prognostic value of worsening renal function and its timing.

INTRODUCTION: Acute decompensated heart failure (ADHF) admissions are frequently complicated by different patterns of serum creatinine (SCr) elevation. We aimed to assess the prognostic impact of worsening renal function (WRF) based on the timing of its occurrence. METHODS: This was a retrospective cohort of patients admitted for ADHF. Standard WRF was defined as an increase in SCr of ≥0.3 mg/dl during hospitalization. WRF timing was classified as early (within 48 hours of admission) or late (>48 hours). Acute kidney injury (AKI) at admission was defined as a rise in SCr of ≥0.3 mg/dl from outpatient baseline measurement to first measurement at admission. The primary endpoint was a composite of all-cause mortality or hospitalization for cardiovascular events at one-year follow-up. RESULTS: Overall, 249 patients were included (mean age 77±11 years, 62% with preserved left ventricular ejection fraction). Early WRF occurred in 49 patients (19.7%) and was associated with a higher risk of the primary outcome (HR 2.49; 95% CI 1.66-3.73), whereas late WRF was not (p=0.411). After stratification for the presence of early WRF and/or AKI at admission, only patients with early WRF but no AKI at admission and patients with both AKI at admission and early WRF showed a higher risk of the primary outcome after multivariate Cox regression. CONCLUSION: Early WRF was associated with a higher risk of the primary outcome. The timing of WRF seems to be an important factor to take into account when considering the prognostic impact of creatinine variations during hospitalization for ADHF.

Urine metabolites for preoperative prediction of acute kidney injury after coronary artery bypass graft surgery.

OBJECTIVE: Acute kidney injury is a common complication after on-pump coronary artery bypass grafting. Prediction of acute kidney injury remains a challenge. Our study aims to identify a panel of urine metabolites for preoperative warning of acute kidney injury after on-pump coronary artery bypass grafting. METHODS: A total of 159 patients undergoing isolated on-pump coronary artery bypass grafting were enrolled from July 7, 2017, to May 17, 2019. Preoperative urine samples were analyzed with the approach of liquid chromatography-mass spectrometry-based urine metabolomics. The study end point was the episode of acute kidney injury within 48 hours postoperatively. The predictive performance was determined by the area under the curve and calibration curve. The results were validated using bootstrap resampling. RESULTS: The acute kidney injury (n = 55) and nonacute kidney injury (n = 104) groups showed significant different metabolic profiling. A total of 28 metabolites showed significant differences between the acute kidney injury and nonacute kidney injury groups. A metabolite panel of 5 metabolites (tyrosyl-gamma-glutamate, deoxycholic acid glycine conjugate, 5-acetylamino-6-amino-3-methyluracil, arginyl-arginine, and L-methionine) was discovered to have a good predicting performance (area under the curve, 0.89; 95% confidence interval, 0.82-0.93), which is higher than the clinical factor-based model (area under the curve, 0.63; 95% confidence interval, 0.53-0.72). Internal validation by bootstrap resampling showed an adjusted area under the curve of 0.88, and the calibration curve demonstrated good agreement between prediction and observation in the probability of postoperative acute kidney injury. Decision curve analysis revealed a superior net benefit of the metabolite model over the traditional clinical factor-based model. CONCLUSIONS: We present 5 urine metabolites related to acute kidney injury after coronary artery bypass grafting. This metabolite model may serve as a preoperative warning of acute kidney injury after on-pump coronary artery bypass grafting.

The association of homocysteine level with the risk of diabetic nephropathy and diabetic retinopathy in NHANES.

AIMS: To examine the association of homocysteine (Hcy) with diabetic nephropathy (DN) and diabetic retinopathy (DR) in a representative United States population. METHODS: This was a cross-sectional study using data from participants in the National Health and Nutrition Examination Survey 2005-2006. Metrics including Hcy level, urinary albumin to creatinine ratio, estimated glomerular filtration rate, and retinopathy grading were collected. Multiple logistic regression models were employed to assess the association of Hcy with DN and DR. RESULTS: 630 participants were included in this study. The Hcy level was significantly higher in those with DN and DR than those without DN and DR. Hcy was associated with an increased risk of DN (OR = 1.31, 95% CI 1.18-1.46; P < 0.001). In the fully adjusted model of DN (model II), compared to participants in quartiles 1 of Hcy, the adjusted ORs for participants in quartiles 2-4 were 1.49 (95% CI 0.52-4.26; P = 0.426), 3.81 (95% CI 1.35-10.73; P = 0.015), and 14.08 (95% CI 3.84-51.66; P = 0.001), respectively. Hcy was also associated with an increased risk of DR (OR = 2.260, 95% CI 1.212-4.216; P = 0.014), but this association was non-significant in the fully adjusted model of DR (model II). CONCLUSIONS: In diabetic patients, Hcy was associated with increased risk of DN in a non-linear manner. In addition, Hcy was associated with the risk of DR, but the association was attenuated after adjusting for confounders. In the future, Hcy can potentially be used as an early screening indicator for diabetic microvascular complications.

A case of membranous nephropathy secondary to asymptomatic Graves' disease.

Although cases of secondary membranous nephropathy associated with autoimmune thyroid disease (AITD) have been reported, most of them, if not all, present with symptomatic thyroid disease. Here we report an asymptomatic case of AITD complicated with secondary membranous nephropathy. A 16-year-old girl was referred to our institute because of proteinuria found by an annual medical checkup. Urinalysis showed a urinary protein creatinine ratio (UPCR) of 3.0 g/gCre. Blood examination revealed that she had Graves' disease, although she did not have any symptoms of hyperthyroidism such as weight loss, anxiety, tremor, tachycardia, or eye symptoms. In a kidney biopsy, periodic acid silver-methenamine staining showed spike formation in the basement membrane. Electron microscopy showed electron-dense deposits on the epithelial side of the glomerular basement membrane. Immunofluorescent staining showed co-localization of thyroid peroxidase and IgG deposition along the glomerular capillary walls. A diagnosis of membranous nephropathy secondary to asymptomatic Graves' disease was made on the basis of results of the examinations. Treatment with thiamazole added to enalapril improved proteinuria (reduction of UPCR to 0.83 g/gCr) and hypoalbuminemia. Consideration should be given to the possibility of AITD in differential diagnosis of etiologies of membranous nephropathy even when typical symptoms of AITD are lacking.

Renal Function and Remission of Hypertension After Bariatric Surgery: a 5-Year Prospective Cohort Study.

PURPOSE: This study examines the effect of Roux-en-Y gastric bypass (RYGB) and laparoscopic adjustable gastric banding (LAGB) on renal function for at least 5 years post-operatively in a tertiary referral center for bariatric surgery. MATERIALS AND METHODS: This prospective cohort study of patients undergoing RYGB and LAGB measured renal function, blood pressure, and diabetes status pre-operatively and then 1 and 5 years post-operatively. Renal function was assessed using the Modification of Diet in Renal Disease (MDRD), Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI), and Cockcroft-Gault formulae. Hypertension and diabetes were defined by the European Society of Hypertension and European Society of Cardiology joint guidelines and American Diabetes Association guidelines, respectively. A sub-group who had completed 10 years post-operative follow-up was also included. RESULTS: Estimated glomerular filtration rate (eGFR) increased over 5 years after RYGB (N = 190; 94 ± 2 mL/min/1.73 m2 to 102 ± 22 mL/min/1.73 m2, p = 0.01) and LAGB (N = 271; 88 ± 1 to 93 ± 22 mL/min/1.73 m2, p = 0.02). In a sub-group with up to 10 years post-operative date, this trend was maintained. In patients with renal impairment, eGFR improved over 5 years (52 ± 2 to 68 ± 7 mL/min/1.73 m2, p = 0.01). Remission of hypertension was greater after RYGB than LAGB at 1 year (32 vs. 16 %, p = 0.008) and at 5 years post-operatively (23 vs. 11 %, p = 0.02). CONCLUSIONS: Bariatric surgery stabilizes eGFR post-operatively for at least 5 years. In a sub-group with renal impairment, eGFR is increased in the first post-operative year and this is maintained for up to 5 years. RYGB is an effective procedure in achieving blood pressure control.

Función renal y factores asociados en el desarrollo de la enfermedad renal crónica en adultos / Renal function and associated factors in the development of chronic kidney disease

Introducción: la Enfermedad Renal Crónica es un problema de salud pública, debido al aumento en la prevalencia y altos costos asociados. Su diagnóstico es tardío, lo que lleva a requerir un tratamiento sustitutivo a través de la diálisis y el trasplante renal. Objetivo: determinar la relación entre la función renal y los factores de riesgo de la Enfermedad Renal Crónica. Métodos: investigación correlacional transversal en sujetos adultos de la Universidad del Desarrollo durante el mes de Octubre de 2013 (n=90). Se aplicó la encuesta renal del Ministerio de Salud de Chile, complementada con un cuestionario con factores de riesgo, validado mediante juicio de expertos con un K promedio de 0,93. Los datos fueron analizados a través del programa SPSS v.15 ®. El análisis descriptivo fue en base a medidas de tendencia central y de variabilidad. Para el análisis inferencial se evaluó la asociación mediante el test de Student. Resultados: dentro de los factores de riesgo se evidenció: tabaquismo (45,6 por ciento), ingesta de alcohol (82,2 por ciento), sedentarismo (71,1 por ciento), consumo de antiinflamatorios (73,3 por ciento), mal nutrición por exceso (57,8 por ciento), entre otros. La media de velocidad de filtración glomerular fue de 84 ml/min/1,732 con una creatinina sérica promedio de 0,98 mg/dl. La asociación entre la velocidad de filtración glomerular y los factores de riesgo estudiados fue significativa (p<0,05). Conclusiones: un gran porcentaje de la población presentó factores de riesgo y se evidenció una asociación entre éstos y la velocidad de filtración glomerular(AU)

Introduction: chronic kidney disease is a public health problem by the increased prevalence, impact on quality of life and associated high costs. His diagnosis delayed, leading to require replacement therapy by dialysis and renal transplantation. Objective: to determine the relationship between renal function and the risk factors of chronic kidney disease in University officials Development 2013. Methods: across-sectional correlational study in adult subjects at the University of Development during the month of October 2013 (n = 90). Renal survey of the Ministry of Health of Chile, supplemented by a questionnaire with risk factors, validated by expert judgment with average K of 0.93 applied. Data were analyzed using SPSS v.15 ® program. Descriptive analysis based on measures of central tendency and variability. For the inferential analysis, the association assessed by Student's t test. Results: among the risk factors are evident: 45.6 percent with smoking, alcohol intake with 82.2 percent, 71.1 percent sedentary lifestyle, consumption of anti-inflammatory in 73.3 percent, poor nutrition 57.8 percent excess, among others. Mean GFR ml/min/1 84 was 732 with an average serum creatinine of 0.98 mg / dl. The association between GFR and risk factors studied was significant (p < 0.05). Conclusion: alarge percentage of the population had risk factors and an association between them and the glomerular filtration rate demonstrated(AU)