#3125 EXTERNAL VALIDATION OF A NOVEL MULTIMARKER GFR ESTIMATING EQUATION

Abstract Background and Aims The use of multiple markers may improve the accuracy in glomerular filtration rate (GFR) estimation especially when interpretation creatinine cystatin C is limited. We sought to externally validate a recently developed multi-marker nuclear magnetic resonance (NMR)-based estimated GFR equation (eGFR-NMR) using biracial Genetic Epidemiology Network Arteriopathy cohort. Method included 224 sex, race/ethnicity, mGFR-category-matched participants. was measured urinary clearance iothalamate (mGFR). calculated eGFR-NMR serum creatinine, valine, myo-inositol, C, age, sex. compared reliability with current eGFR equations (2021 Chronic Kidney Disease Collaboration for [eGFR-Cr] [eGFR-Cr-CysC]) median bias, precision, metrics. In particular, we evaluated its performance race subgroups. Results overall cohort, mean age 63 (±8) years, 54% were females, 49% Black individuals, mGFR 78.7 (±24.3) ml/min/1.73 m2. overestimated by 2 mL/min/1.73 m2 (95% CI, 4 0.7) while eGFR-Cr-CysC underestimated −5 −2 −7). All had acceptable When stratified race, performed best among males <65 years (Figure 1). this subgroup, unbiased (bias, 2mL/min/1.73 [95% -3 10]) substantial biases eGFR-Cr 17 9 24]) 15 6 20]). other subgroups, measures eGFR-NMR, eGFR-Cr, generally similar. Conclusion can be used estimate more accurate than CKD-EPI years.