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Updated: Sep 7, 2025
Physiology Lab Demonstration: Glomerular Filtration Rate in a Rat
Published on: July 26, 2015
[Glomerular filtration rate in centenarians with coronary artery disease.]
S V Topolyanskaya1, T A Eliseeva2, A I Sanina2
1I.M. Sechenov First Moscow State Medical University, 8 build. 2 Trubetskaya str., Moscow 119991, Russian Federation,
Insights
Comparing glomerular filtration rate (GFR) equations in elderly coronary artery disease (CAD) patients reveals significant differences, particularly at lower creatinine levels, impacting chronic kidney disease (CKD) staging.
Area of Science:
- Nephrology
- Cardiology
- Geriatrics
Background:
- Coronary artery disease (CAD) is prevalent in the elderly.
- Accurate assessment of kidney function, specifically glomerular filtration rate (GFR), is crucial in patients with CAD.
- Several equations exist to estimate GFR, but their performance may vary in specific populations like long-living individuals.
Purpose of the Study:
- To compare the performance of four common equations (CKD-EPI, MDRD, BIS1, Cockcroft-Gault) in estimating GFR.
- To analyze the relationship between estimated GFR (eGFR) and clinical/laboratory parameters in elderly CAD patients.
- To evaluate the impact of different GFR equations on chronic kidney disease (CKD) staging in this population.
Main Methods:
- Cross-sectional study involving 270 patients aged 90-106 years with diagnosed CAD.
- Calculation and comparison of eGFR using CKD-EPI, MDRD, BIS1, and Cockcroft-Gault equations.
- Analysis of CKD staging based on eGFR values derived from each equation.
Main Results:
- Mean eGFR values varied significantly between equations: CKD-EPI (51.4 ml/min), MDRD (50.9 ml/min), BIS1 (38.4 ml/min), and Cockcroft-Gault (40.6 ml/min).
- CKD-EPI and MDRD showed similar staging results, with most patients in stage 3A. BIS1 classified the majority (64.1%) in stage 3B, with no patients above 60 ml/min.
- Significant differences in eGFR were observed between equation groups (CKD-EPI/MDRD vs. BIS1/Cockcroft-Gault) at low and medium creatinine levels, with maximum discrepancies of 21 ml/min.
Conclusions:
- The choice of GFR equation significantly impacts eGFR values and CKD staging in elderly patients with CAD.
- BIS1 and Cockcroft-Gault equations tend to underestimate GFR in this population compared to CKD-EPI and MDRD.
- These discrepancies highlight the need for careful consideration of GFR estimation methods in clinical practice for this specific demographic.
Abstract:
The study objective was to compare the CKD-EPI, MDRD, BIS1, and Cockroft-Gault equations for calculating GFR, and analyze the various relationships between the glomerular filtration rate and clinical and laboratory parameters in long-living patients with coronary artery disease (CAD). A cross-sectional study of 270 patients from 90 to 106 years old, hospitalized with CAD diagnosis, was performed. The mean estimated GFR according to CKD-EPI was 51,4±14,2 ml/min, MDRD - 50,9±13,4, BIS1 - 38,4±7,7, Cockroft-Gault - 40,6±12,6 ml/min. Only 75 patients (27.8%) had CKD-EPI eGFR greater than or equal to 60 ml/min. The most common stage of chronic kidney disease was stage 3A, while stage CKD 5 did not occur at all. CKD staging results calculated using the MDRD and CKD-EPI equations were similar. However, when using the BIS1 equation, eGFR of more than 60 ml/min was not observed in any patient, and the vast majority of patients (64,1%) had stage 3B CKD. At high creatinine levels, there were no considerable differences between eGFR according to different equations, while at low and medium creatinine values, there were significant differences in eGFR, assessed using the CKD-EPI and MDRD equations on the one hand and BIS1 and Cockroft-Gault on the other. The maximum differences reached 21 ml/min.
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