scholarly journals Simple Cystatin C Formula Compared to Serum Creatinine-Based Formulas for Estimation of Glomerular Filtration Rate in Patients with Mildly to Moderately Impaired Kidney Function

2012 ◽  
Vol 35 (6) ◽  
pp. 649-654 ◽  
Author(s):  
Sebastjan Bevc ◽  
Radovan Hojs ◽  
Robert Ekart ◽  
Maksimiljan Gorenjak ◽  
Ludvik Puklavec
Author(s):  
Balkar Chand ◽  
Lovleen Bhatia ◽  
Kanchan Vohra

Background: Estimated glomerular filtration rate (eGFR) is accepted as the best indicator of kidney function and commonly assessed from serum creatinine (Cr) and cystatin C (Cys-C) based equations. The present cross-sectional, observational study aimed to assess eGFR using a new and validated Full Age Spectrum (FAS) equation and compared with eGFR assessed using old and established equations in hypertensive patients. Materials and Methods: Overall, 60 subjects were recruited for the study, including 30 hypertensive patients and 30 age and sex matched healthy subjects. Serum creatinine and cystatin C were measured using commercial biochemical kits. These levels were used to derive and compare eGFR using our different equations, namely, Cockcroft and Gault (CG), Modification of Diet in Renal Disease (MDRD), Chronic Kidney Disease-epidemiology collaboration (CKD-EPI), and FAS equation. Student t-test was used for comparison between two groups and One-way ANOVA test was used to find multiple comparison with-in the hypertensive and control group. Pearson’s Univariate correlation followed by multiple linear regression analysis was applied to find independent predictors of eGFR. All data were analyzed using Sigma-Stat. Results: There was significant difference found in the eGFR levels using different equations in hypertensive subjects as compared to healthy subjects (P<0.01). With–in hypertensive subjects and with-in heathy subjects, a significant difference was also reported (both P<0.01). For FAS-based GFR, age was found as independent predictor of eGFR by all FAS equations. eGFR estimated using Cr based equations resulted in significant difference in categorizing number of subjects into CKD v/s non-CKD depending on their eGFR levels. But there was no difference found for the above in serum cystatin C based equations (P=0.26). Conclusion: Present data showed that eGFR derived using all set of equations resulted in variable eGFR levels. But, use of Cr based equations instead of Cys-C or combine Cr-Cys based equations resulted in wide variation i.e. change in GFR due to change in marker.


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.


2015 ◽  
Vol 42 (2) ◽  
pp. 141-147 ◽  
Author(s):  
Carmen A. Peralta ◽  
Paul Muntner ◽  
Rebecca Scherzer ◽  
Suzanne Judd ◽  
Mary Cushman ◽  
...  

Background/Aims: Persons with occult-reduced estimated glomerular filtration rate (eGFR <60 ml/min/1.73 m2 detected by serum cystatin C but missed by creatinine) have high risk for complications. Among persons with preserved kidney function by creatinine-based eGFR (eGFRcreat >60 ml/min/1.73 m2), tools to guide cystatin C testing are needed. Methods: We developed a risk score to estimate an individual's probability of reduced eGFR by cystatin C (eGFRcys <60 ml/min/1.73 m2) in The Reasons for Geographic and Racial Differences in Stroke (REGARDS) study and externally validated in the Third National Health and Nutrition Examination Survey (NHANES III). We used logistic regression with Bayesian model averaging and variables available in practice. We assessed performance characteristics using calibration and discrimination measures. Results: Among 24,877 adults with preserved kidney function by creatinine, 13.5% had reduced eGFRcys. Older and Black participants, current smokers and those with higher body mass index, lower eGFRcreat, diabetes, hypertension and history of cardiovascular disease were more likely to have occult-reduced eGFR (p < 0.001). The final risk function had a c-statistic of 0.87 in REGARDS and 0.84 in NHANES. By risk score, 72% of occult-reduced eGFR cases were detected by screening only 22% of participants. Conclusions: A risk score using characteristics readily accessible in clinical practice can identify the majority of persons with reduced eGFRcys, which is missed by creatinine.


Circulation ◽  
2020 ◽  
Vol 141 (Suppl_1) ◽  
Author(s):  
Alex R CHANG ◽  
G. C Wood ◽  
Adam Cook ◽  
Xin Chu ◽  
Morgan Grams

Background: Persons with morbid obesity are at increased risk for end-stage kidney disease, and prior studies have shown an association between bariatric surgery and improvements in creatinine-based estimated glomerular filtration rate (eGFR cr ). However, eGFR cr could be biased by loss of muscle mass after surgery, and creatinine-cystatin C estimated glomerular filtration rate (eGFR cr-cyc ) has been shown to be more accurate in this setting. Methods: We matched 144 patients who underwent bariatric surgery on pre-surgery age, sex, race, body mass index (BMI), and eGFR cr with 144 morbidly obese non-surgery patients at Geisinger with serial biobanked serum samples. We measured filtration markers (creatinine, cystatin C, beta-2 microglobulin [B2M] and beta-trace protein [BTP], and calculated eGFR cr-cyc using the CKD-EPI combined equation. Using mixed effects models with random intercepts, we compared changes in filtration markers and eGFR cr-cyc between surgery and non-surgery groups. Results: Mean (SD) values for age, BMI, and eGFR cr were 48.2 (10.4) years, 45.2 (6.3) kg/m 2 , and 91.7 (17.5) ml/min/1.73m 2 ; 87.5% were female, 0.7% were black, 50.3% had hypertension, and 41.0% had type 2 diabetes. Mean eGFR cr-cyc slope in the surgery group was -0.41 ml/min/1.73m 2 /yr (95% CI: -0.74, -0.08) over a mean follow-up of 9.2 (1.4) years, compared to -1.43 ml/min/1.73m 2 /yr in the non-surgery group over a mean follow-up of 8.2 (1.1) years. Bariatric surgery was associated with a 1.02 ml/min/1.73m 2 /yr slower decline in eGFR cr-cyc , and smaller increase in all 4 filtration markers (p< 0.02 for all comparisons). Conclusions: Bariatric surgery is associated with slower decline in kidney function, as assessed by eGFR cr-cyc , B2M and BTP.


1982 ◽  
Vol 140 (2) ◽  
pp. 185-187 ◽  
Author(s):  
P. Vestergaard ◽  
Mogens Schou ◽  
Klaus Thomsen

The effect of long-term lithium treatment on the kidneys has generated concern among psychiatrists, and proposals have been made that routine determinations of serum lithium and serum TSH should be supplemented with control of the kidney function through regular determinations of serum creatinine, glomerular filtration rate, and renal concentrating ability, as well as through kidney biopsy in certain circumstances.


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