Camilla Zumsteg

ABSTRACT

Glomerular filtration rate (GFR) is the principal indicator used to evaluate renal function and to diagnose, stage, and monitor chronic kidney disease (CKD). Although direct determination of GFR through renal clearance techniques remains the reference approach, routine clinical implementation is constrained by procedural complexity, cost, and limited accessibility. Inulin clearance continues to serve as the benchmark method because of its ideal physiological characteristics; however, its practical limitations have encouraged the adoption of alternative approaches.