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Updated: Jul 26, 2025
A High-throughput Method for Measurement of Glomerular Filtration Rate in Conscious Mice
Published on: May 10, 2013
Factors influencing glomerular filtration rate as estimated using preoperative creatinine and cystatin C levels
Insights
Physical performance, measured by the Short Physical Performance Battery (SPPB) score, can help identify overestimations in estimated glomerular filtration rate (eGFR) calculated from serum creatinine. A lower SPPB score indicates a higher likelihood of eGFR overestimation in patients undergoing cardiovascular surgery.
Area of Science:
- Nephrology
- Cardiovascular Surgery
- Geriatrics
Background:
- Serum creatinine-based estimated glomerular filtration rate (eGFRcre) is standard for assessing renal function but can overestimate true GFR.
- Overestimated renal function may lead to underestimation of risks for mortality and postoperative complications in cardiovascular surgery patients.
- Cystatin C (eGFRcys) offers an alternative marker for GFR estimation.
Purpose of the Study:
- To compare eGFRcre and eGFRcys for preoperative renal function assessment in cardiovascular surgery patients.
- To identify factors influencing the overestimation of renal function by eGFRcre.
Main Methods:
- Retrospective analysis of 88 cardiovascular surgery patients with preoperative serum creatinine and cystatin C measurements.
- Multiple regression analysis to examine correlations between eGFRcre, eGFRcys, their ratio, and patient factors.
- Defined clinically significant renal function overestimation as eGFRcre/eGFRcys > 1.2.
Main Results:
- eGFRcre/eGFRcys ratio was significantly negatively correlated with the Short Physical Performance Battery (SPPB) score.
- An SPPB score of 9 points or less was identified as a cutoff for significant renal function overestimation.
- The chair stand test, a component of SPPB, demonstrated similar discriminative power for identifying renal function overestimation.
Conclusions:
- The SPPB score can effectively identify patients with likely overestimation of GFR.
- The chair stand test serves as a viable alternative to the full SPPB for detecting renal function overestimation, particularly when SPPB is challenging to administer.
Objectives:
Estimated glomerular filtration rate (eGFR) using serum creatinine (Cr) is commonly used to evaluate renal function. However, it can be influenced by other factors, which can risk the overestimation of the true GFR. Impaired renal function prior to cardiovascular surgery reportedly increases mortality and the incidence of postoperative complications. Thus, overestimation of renal function may affect the assessment of postoperative complication risks. Therefore, we aimed to compare the eGFR calculated from serum Cr and cystatin C (Cys-C) levels to assess preoperative renal function and to investigate factors affecting renal function overestimation.
Materials And Methods:
88 patients admitted for cardiovascular surgery who had preoperative serum Cr and Cys-C measurements were included in the study. Correlations between factors associated with eGFR calculated from serum Cr (eGFRcre) and Cys-C (eGFRcys) and their ratio (eGFRcre/eGFRcys) were examined using multiple regression analysis.
Results:
Multiple regression analysis revealed that eGFRcre/eGFRcys was significantly negatively correlated with the Short Physical Performance Battery score (SPPB). A clinically significant difference in renal function overestimation was defined as GFRcre/eGFRcys > 1.2, with a cutoff value of 9 points for the SPPB score. The chair stand test, a component of the SPPB, had the same discriminative power as the SPPB for identification of renal function overestimation.
Conclusion:
The SPPB can be used to identify likely GFR overestimation in patients. Additionally, the chair stand test may be used as an alternative to the SPPB for the identification of renal function overestimation when the SPPB is difficult to perform.
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