Table 1:

Potential indications for testing the reserve function of the kidney

Low GFR	Normal GFR	High GFR
Known reduced kidney mass - solitary kidney - congenital anomalies of the kidney and the urinary tract	Prior to kidney mass reducing interventions - kidney donation - nephrectomy	Enhanced kidney clearance - obesity - diabetes - burns - sepsis
Suspected renal frailty of the kidney - before high-risk pregnancy - before high-risk major surgery (e.g. cardiac surgery) - before chemotherapy (e.g. HSCT) - during nephrotoxic treatments - assessment of renal recovery after AKI - cardiorenal syndrome - known cardiovascular disease (hypertension, diabetes) - systemic sclerosis - the aging kidney