Kidney Week

Abstract: TH-PO1033

New Argentine Equation to Estimate the Glomerular Filtration Rate

Session Information

• CKD Progression and Complications: Diagnosis, Prognosis, Risk Factors
  November 02, 2023 | Location: Exhibit Hall, Pennsylvania Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: CKD (Non-Dialysis)

• 2302 CKD (Non-Dialysis): Clinical, Outcomes, and Trials

Authors

• Fernández, Pehuén, Hospital Privado Centro Medico de Cordoba, Cordoba, Córdoba, Argentina

Pehuén Fernández,

• Nores, María Laura, Universidad Nacional de Cordoba, Cordoba, Córdoba, Argentina

María Laura Nores,

• Lujan, Pablo Rodrigo, Hospital Privado Centro Medico de Cordoba, Cordoba, Córdoba, Argentina

Pablo Rodrigo Lujan,

• Naser, Sofia, Hospital Privado Centro Medico de Cordoba, Cordoba, Córdoba, Argentina

Sofia Naser,

• De Arteaga, Javier, Hospital Privado Centro Medico de Cordoba, Cordoba, Córdoba, Argentina

Javier De Arteaga,

• de la Fuente, Jorge, Hospital Privado Centro Medico de Cordoba, Cordoba, Córdoba, Argentina

Jorge de la Fuente,

• Douthat, Walter, Hospital Privado Centro Medico de Cordoba, Cordoba, Córdoba, Argentina

Walter Douthat,

• Chiurchiu, Carlos Raúl, Hospital Privado Centro Medico de Cordoba, Cordoba, Córdoba, Argentina

Carlos Raúl Chiurchiu,

Background

Latin Americans are poorly represented in the current glomerular filtration rate equations (eGFR), so their predictions are difficult to extrapolate in our population.
Objetive: to develop a new equation to estimate GFR based on data from Argentina and compare its performance with those currently available.

Methods

Cross-sectional study. We included all adults whose GFR was measured with urinary clearance of iothalamate (mGFR) between 2007 and 2017 (development sample–DS-, n=583). The chosen equation was based on a quasi-likelihood model with identity variance function and logarithmic link to predict mGFR from the square root of creatinine, age, sex, monoren, albumin and the logarithm of urea. Later, an independent sample was added between 2018 and 2019 (temporary validation sample -TVS-, n=78). The performance of the new equation was compared with the previous ones (MCQ, MDRD 4 and 6, CKD-EPI 2009 and 2021) in the DS (by 10-fold cross-validation) and in the TVS.

Results

There were no differences in the baseline characteristics in both samples and they presented a wide range in the mGFR (1.9-186.6 ml/min/1.73 m²).
Within the previous equations, CKD-EPI (2009 and 2021) obtained the best performance (comparator).
In the DS, Argentine Equation (AE) presented a lower RMSE, higher P15, bias median closer to zero, and a higher %CC compared to CKD-EPI 2009. In addition, from Q1, M, and Q3 of the bias, a greater shift to the left of CKD-EPI 2009. Compared with CKD-EPI 2021, AE obtained a median bias closer to 0, and in the rest of the metrics it was slightly lower, although very similar (table 1).
In the TVS, AE presented a lower RMSE, higher r, P30 and %CC compared to CKD-EPI in its two versions. In addition, it presented a median bias closer to 0 and a higher P15 compared to CKD-EPI 2009.

Conclusion

AE presented a better global performance to estimate GFR in residents of Argentina compared to the currently equations.