Kidney Week

Abstract: SA-PO950

Cystatin C-Based Equations Underestimate Glomerular Filtration Rate in Men With or at Risk for Mesoamerican Nephropathy

Session Information

• CKD: Observational Research and Patient-Oriented Interventions
  November 05, 2022 | Location: Exhibit Hall, Orange County Convention Center‚ West Building
  Abstract Time: 10:00 AM - 12:00 PM

Category: CKD (Non-Dialysis)

• 2202 CKD (Non-Dialysis): Clinical‚ Outcomes‚ and Trials

Authors

• Raines, Nathan H., Beth Israel Deaconess Medical Center, Boston, Massachusetts, United States

Nathan H. Raines,

• Inker, Lesley Ann, Tufts Medical Center, Boston, Massachusetts, United States

Lesley Ann Inker,

• Seegmiller, Jesse C., University of Minnesota Academic Health Center, Minneapolis, Minnesota, United States

Jesse C. Seegmiller,

• Brooks, Daniel R., Boston University School of Public Health, Boston, Massachusetts, United States

Daniel R. Brooks,

• Gonzalez, Marvin Antonio, Research Center on Health, Work, and Environment, National Autonomous University of Nicaragua, León, Leon, Nicaragua

Marvin Antonio Gonzalez,

• Friedman, David, Beth Israel Deaconess Medical Center, Boston, Massachusetts, United States

David Friedman,

Background

Estimated glomerular filtration rate (eGFR) equations using serum creatinine or cystatin C may introduce bias when applied to populations other than those in which the equation was derived. The accuracy of eGFR equations has not been evaluated in populations with high rates of Mesoamerican nephropathy (MeN), a syndrome of chronic kidney disease of unknown cause (CKDu) usually affecting young men from agricultural areas who are of mixed ancestry, perform strenuous labor, and live in poverty.

Methods

We compared eGFR from three modern and three historically-used equations against measured GFR (mGFR) by serum iohexol disappearance in 50 men aged 19-45 from a population with high risk for MeN in Nicaragua.

Results

mGFR ranged from 24 to 137ml/min/1.73m². Among modern equations, the CKD Epidemiology Collaboration (CKD-EPI) creatinine equation (2021) had minimal bias and good accuracy, while equations that incorporated cystatin C led to a systematic underestimation of GFR and poorer overall performance (Fig. 1), potentially resulting in misdiagnosis (Fig. 2).

Conclusion

CKD-EPI creatinine (2021) accurately estimates GFR in men with or at risk for MeN, whereas Cystatin C-based equations do not. More studies are needed to extend these results to other populations affected by CKDu.

Funding

• Private Foundation Support