scholarly journals Cystatin and Glomerular Filtration Rate in Obese Versus Non-obese Adolescents

2021 ◽  
Vol 9 (B) ◽  
pp. 1453-1457
Author(s):  
Azza Abd El-Shaheed ◽  
Nermine N. Mahfouz ◽  
Reham F. Fahmy ◽  
Mona A. Elabd ◽  
Hiba Sibaii ◽  
...  

Background: Obesity is well known as an independent risk factor for chronic kidney disease. Thus meticulous assessment of renal function is more essential in obese individuals. Glomerular filtration rate (GFR) is commonly estimated based on serum creatinine (Cr).  However, using Cr as marker of kidney function has some limitations and Cystatin C has been reported as an alternative marker. Aim of work: This study was designed to assess renal function using both GFR and cystatin in obese adolescents. Methods: This case-control study enrolled ninety Egyptian adolescents aged between 10 and 18 years old who were divided equally into two groups according to body mass index (obese and non-obese).  Each participant was subjected to full medical history taking, anthropometric measures, and Laboratory investigation including CBC, serum Cr, estimated GFR and cystatin C. Results:  Serum Cr level was significantly higher in obese adolescents compared to non-obese mean value (0.94) and (0.79) resepectively. Also, eGFR based on Cr was significantly lower in obese group compared to controls (73.1) and ( (85.30)respectively. Cystatin C showed non-significant higher levels in obese group versus controls with mean value (2.28) and (1.85)respectively. Cystatin C at Cut-off value of 1.525 and 95% CI showed sensitivity of 47.2% and specificity of 63.9% for evaluation of kidney affection in obese children and adolescences. Conclusion: GFR is affected in obese adolescence with elevation of serum creatinine and unexpected non significant elevation of cystatin C in obese adolescence when compared by control group. Keywords: Cystatin, Creatinine, Pediatric obesity, GFR, renal function.

Author(s):  
Lothar Thomas ◽  
Andreas R. Huber

AbstractAssessment and follow-up of renal dysfunction is important in the early detection and management of chronic kidney disease. The glomerular filtration rate (GFR) is the most accurate measurement of kidney disease and is reduced before the onset of clinical symptoms. Drawbacks to the measurement of GFR include the high cost and incompatibility with routine laboratory monitoring. Serum creatinine determination is a mainstay in the routine laboratory profile of renal function. The measurement of serum cystatin C has been proposed as a more sensitive marker for GFR. According to National Kidney Foundation-K/DOQ1 clinical guidelines for chronic kidney disease, serum markers should not be used alone to assess GFR. Based on prediction equations, clinical laboratories should report an estimate of GFR, in addition to reporting the serum value. In this article, information is presented on how best to estimate GFR using prediction equations for adults and for children. Using serum creatinine concentration with the Modification of Diet in Renal Disease (MDRD) study equation offers a suitable estimation of GFR in adults. The cystatin C prediction equation with the use of a prepubertal factor seems superior to creatinine-based prediction equations in children of <14years.Clin Chem Lab Med 2006;44:1295–302.


2011 ◽  
Vol 1 (1) ◽  
pp. 10 ◽  
Author(s):  
YingBin Jia ◽  
Yun Shi ◽  
XiaoDong Guan ◽  
Jian Li ◽  
BaiMeng Zhang ◽  
...  

This study aimed to assess the mid-term renal function of abdominal aortic aneurysm patients following suprarenal endovascular repair. From March 2005 to December 2009, 290 abdominal aortic aneurysm patients were included in the study and grouped according to whether they had received infrarenal or suprarenal endovascular aneurysm repair. Suprarenal endovascular aneurysm repair was performed in 173 patients, with a mean age of 72(±8) years (85.0% male). Infrarenal endovascular aneurysm repair was performed in 117 patients, with a mean age of 71(±9) years (90.6% male). Preoperative and one week, 1-, 3-, 6- and 12-month postoperative serum creatinine and cystatin C values were recorded. Estimated glomerular filtration rate was calculated by cystatin-based formula and Cr-based Cockcroft formula. The t-test was used to determine statistical differences between or within groups. All patients received Talent or Zenith endograft. Patients’ characteristics and operative files in the two groups were well matched. Preoperative serum creatinine and cystatin C were 82 (±8) mmol/L and 0.89 (±0.11) mg/L for suprarenal endovascular aneurysm repair, respectively, and 81 (±11) mmol/L and 0.87 (±0.15) mg/L, respectively, for infrarenal endovascular aneurysm repair; no differences were observed between the two groups. Compared to preoperative renal markers within each group, a deterioration in serum creatinine, cystatin C and estimated glomerular filtration rate values was found at one week and 12 months after surgery(P&lt;0.05). A deterioration in cystatin C [SR:(0.93±0.17) mg/L, IR: (0.92±0.31) mg/L] and estimated glomerular filtration rate by cystatin C was also found at six months after surgery(P&lt;0.05). However, no differences in patient serum creatinine, cystatin C and estimated glomerular filtration rate values were observed between groups at each follow-up time interval. There was no greater significant difference in the association of the use of suprarenal fixation with midterm postoperative renal injury than with infrarenal fixation.


1998 ◽  
Vol 44 (7) ◽  
pp. 1535-1539 ◽  
Author(s):  
Brian G Keevil ◽  
Eric S Kilpatrick ◽  
Simon P Nichols ◽  
Paul W Maylor

Abstract To assess the inherent potential for detecting mild to moderate reductions in glomerular filtration rate, this study determined the biological variability of serum cystatin C and creatinine in 12 healthy subjects. After accounting for analytical variation, interindividual variance accounted for 93% and intraindividual variance accounted for 7% of serum creatinine biological variation. As such, to lie outside the assay reference interval, some subjects must exceed 13 SD from their usual mean value, whereas in others, a change of only 2 SD would be sufficient. For cystatin C, interindividual variation explained 25% and intraindividual variance explained 75% of biological variability. Therefore, the upper limit of the population reference interval for cystatin C is seldom more than 3–4 SD from the mean value of any healthy individual. The critical difference for sequential values significant at P ≤0.05 was calculated as 37% for serum cystatin C and 14% for serum creatinine. We conclude that cystatin C is potentially a better marker for detecting impaired renal function than serum creatinine, but serum creatinine is probably still the better marker for detecting temporal changes of renal function in individuals with established renal disease.


Author(s):  
Julie Mouron-Hryciuk ◽  
François Cachat ◽  
Paloma Parvex ◽  
Thomas Perneger ◽  
Hassib Chehade

AbstractGlomerular filtration rate (GFR) is difficult to measure, and estimating formulas are notorious for lacking precision. This study aims to assess if the inclusion of additional biomarkers improves the performance of eGFR formulas. A hundred and sixteen children with renal diseases were enrolled. Data for age, weight, height, inulin clearance (iGFR), serum creatinine, cystatin C, neutrophil gelatinase-associated lipocalin (NGAL), parathyroid hormone (PTH), albumin, and brain natriuretic peptide (BNP) were collected. These variables were added to the revised and combined (serum creatinine and cystatin C) Schwartz formulas, and the quadratic and combined quadratic formulas. We calculated the adjusted r-square (r2) in relation to iGFR and tested the improvement in variance explained by means of the likelihood ratio test. The combined Schwartz and the combined quadratic formulas yielded best results with an r2 of 0.676 and 0.730, respectively. The addition of BNP and PTH to the combined Schwartz and quadratic formulas improved the variance slightly. NGAL and albumin failed to improve the prediction of GFR further. These study results also confirm that the addition of cystatin C improves the performance of estimating GFR formulas, in particular the Schwartz formula.Conclusion: The addition of serum NGAL, BNP, PTH, and albumin to the combined Schwartz and quadratic formulas for estimating GFR did not improve GFR prediction in our population. What is Known:• Estimating glomerular filtration rate (GFR) formulas include serum creatinine and/or cystatin C but lack precision when compared to measured GFR.• The serum concentrations of some biological parameters such as neutrophil gelatinase-associated lipocalin (NGAL), parathyroid hormone (PTH), albumin, and brain natriuretic peptide (BNP) vary with the level of renal function. What is New:• The addition of BNP and PTH to the combined quadratic formula improved its performance only slightly. NGAL and albumin failed to improve the prediction of GFR further.


Folia Medica ◽  
2012 ◽  
Vol 54 (4) ◽  
pp. 5-13 ◽  
Author(s):  
Bilyana H. Teneva

Abstract In liver cirrhosis patients awaiting liver transplantation, it is prognostically equally important to assess the renal function before and after transplantation. This is evidenced by the inclusion of serum creatinine in the Model for End-Stage Liver Disease (MELD) score. Most of the causes of renal failure in liver cirrhosis are functional, the acute kidney damage including prerenal azotemia, acute tubular necrosis and hepatorenal syndrome. A major index of the renal function, the glomerular filtration rate (GFR) is determined in a specific way in patients with liver cirrhosis. Clinically, serum creatinine is considered the best indicator of kidney function, although it is rather unreliable when it comes to early assessment of renal dysfunction. Most of the patients with liver cirrhosis have several concomitant conditions, which are the reason for the false low creatinine levels, even in the presence of moderate to severe kidney damage. This also holds for the creatinine clearance and creatinine-based estimation equations for assessment of the glomerular filtration rate (the Cockroft-Gault and MDRD formulas), which overestimate the real glomerular filtration. Clearance of exogenous markers is considered a gold standard, but the methods for their determination are rather costly and hard to apply. Alternative serum markers (e.g., cystatin C) have been used, but they should be better studied in cases of liver cirrhosis assessment.


2020 ◽  
Vol 105 (9) ◽  
pp. e8.2-e9
Author(s):  
Rachel Boys

AimRenal toxicity causes major morbidity following chemotherapy- abnormal iGFRs may be detected in up to 73.7% of patients.1 Creatinine is universally used as a biomarker to track fluctuating function and to calculate surrogate glomerular filtration rate (GFR) in the form of estimating equations.2 There is concern regarding the suitability of creatinine as a biomarker in this population, and it is proposed that cystatin C as a biomarker alone and also included in estimating equations may offer improved clinical suitability and accuracy.3MethodsIn this prospective, longitudinal study over a period of 18 months, 132 combined isotope GFR (iGFR), creatinine and cystatin C measurements were taken from 48 paediatric oncology patients at a Northern Children’s Hospital. Correlation and agreement analysis was performed for both individual biomarkers and estimating equations. Sensitivity data, along with ROC curve analysis was performed for all biomarkers and estimating equations. Data from three identified patients was isolated to examine individual patient variation over time.ResultsCreatinine identified only 1/32 patients with an abnormal iGFR (<90 ml/min/1.73 m2) compared to cystatin C which identified 12/32. Creatinine values and both estimating equations failed to change significantly over a period of declining iGFR though cystatin C did show a significant inverse increase (p<0.05). Bland Altman analysis for both the creatinine and combined equation showed poor agreement (mean difference -64 ml/min/1.3 m2 and -20 ml/min/1.73 m2 respectively). All biomarkers and equations showed poor sensitivity to detect an abnormal iGFR either below 70 ml/min/1.73 m2 or 90 ml/min/1.73 m2. A transformation factor applied to the equations significantly improved the sensitivity and clinical applicability of all equations. The data from three individual patients failed to reveal any significant intra-patient relationships.ConclusionData from this study cannot support the use of creatinine or cystatin C as a single biomarker to monitor renal function in children undergoing chemotherapy. Newer cystatin C and creatinine combined equations, whilst offering statistical superiority, do not offer the clinical superiority to replace iGFR or provide a tool for accurate dose calculations. A transformation factor can be applied to the results gained from the estimating equations to significantly improve the detection of abnormal iGFR, though work in other patient cohorts is needed to support this. Previous work also supported the use of a transformation factor, though application of their transformation factor to this current cohort failed to replicate the 100% sensitivity findings previously demonstrated4. Three patients were identified from the cohort and their paired iGFR and estimated GFR were monitored prospectively, over a period of approximately a year. Significant variation was observed between iGFR and eGFR at each time point for all three patients and therefore personalisation of GFR estimation from baseline iGFR and demographic data could not be proposed. This requires exploration in a larger cohort with the possible inclusion of additional baseline variables.ReferencesCRUK Survival trends over time in Children’s Cancers. 1.2015. https://www.cancerresearchuk.org/health-professional/cancer-statistics/childrens-cancers/survival#heading-Two Accessed 28th March 2019.NICE ( 2013) CG169 Acute kidney injury: Prevention, detection and management of acute kidney injury up to the point of renal replacement therapy.Barnfield, MC, Burniston, MT, Reid, U, et al. Cystatin C in assessment of glomerular filtration rate in children and young adults suffering from cancer. Nuclear Medicine Communications 2013;34:609–614.Dodgshun, AJ, Quinlan, C, Sullivan, MJ. Cystatin C based equation accurately estimates glomerular filtration rate in children with solid and central nervous system tumours: enough evidence to change practice? Pediatric Blood and Cancer 2016;63:1535–1538.


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