Refining GFR estimation: a quest for the unobservable truth?

Assessing glomerular filtration rate (GFR), which is central to evaluating kidney health, remains challenging. Measured GFR is not widely available and lacks standardization. Estimated GFR can be highly inaccurate for some patients and has limited applicability to many patient populations, such as those who are acutely ill. Recent metabolomic advances show promise for identifying new filtration markers that might enhance GFR estimation. Improving GFR assessment will require refinement in both GFR measurement and estimation methods.