Estimating baseline creatinine levels based on the kidney parenchymal volume

Area of Science:

• Nephrology
• Radiology
• Medical Imaging

Background:

• Acute kidney injury (AKI) diagnosis is often hindered by the absence of a baseline serum creatinine (Cr) value.
• Establishing a baseline Cr is crucial for accurate AKI assessment.
• Minimal change disease (MCD) is a common condition that predisposes patients to AKI.

Purpose of the Study:

• To develop a regression equation correlating kidney morphology (parenchymal volume) with kidney function (serum creatinine).
• To estimate baseline Cr in patients with minimal change disease (MCD).
• To improve the diagnostic accuracy of AKI in specific patient populations.

Main Methods:

• Analysis of 119 participants using CT scans, divided into derivation and validation cohorts.
• Development of a parenchymal volume (PV)-based regression equation for estimated glomerular filtration rate (eGFR).
• Estimation and comparison of baseline Cr in 43 MCD patients using the developed equation.

Main Results:

• A PV-based regression equation was established: eGFR = 0.375 × PV - 0.395 × age - 2.93 × male sex - 13.3 × hypertension - 14.0 × diabetes - 0.210 × height + 82.0.
• The equation demonstrated good correlation with measured eGFR and Cr values in the validation group (r=0.46, p=0.01 and r=0.51, p=0.004).
• In MCD patients, estimated baseline Cr significantly correlated with actual baseline Cr (r=0.52, p<0.001), enabling effective AKI diagnosis (kappa=0.76, p<0.001).

Conclusions:

• The developed PV-based regression equation shows promise for estimating baseline Cr and diagnosing AKI in MCD patients.
• This novel approach may address the challenge of missing baseline Cr values in AKI diagnosis.
• Further validation in diverse AKI populations is recommended to broaden clinical applicability.