Age-adapted versus age-independent eGFR thresholds to diagnose CKD: integrating the debate and charting a balanced path forward.

The debate over whether to use age-adapted or age-independent estimated glomerular filtration rate (eGFR) cut-offs for diagnosing chronic kidney disease (CKD) reflects a fundamental tension between physiological understanding and clinical pragmatism. Age-adapted proponents highlight robust evidence that GFR declines naturally with age, with many healthy older adults falling below the traditional 60 ml/min/1.73 m2 threshold. They argue that fixed cut-offs risk overdiagnosing CKD in the elderly, potentially leading to unnecessary anxiety and treatment, while underrecognizing risk in younger individuals whose GFRs are abnormal for their age. Physiological and longitudinal studies support this view, suggesting age-specific percentiles may better reflect true pathology. Conversely, advocates for age-independent thresholds emphasize that age-related GFR decline is not benign. Large epidemiological studies show that older adults with an eGFR of 45-59 ml/min/1.73 m2 are at increased risk of kidney failure, cardiovascular events and mortality, even in the absence of albuminuria. They caution that redefining CKD based on age could exclude high-risk older adults from beneficial therapies and research and that 'healthy' reference populations may harbour undiagnosed disease. A balanced approach recognizes the physiological realities of aging while not ignoring the clinical risks associated with reduced kidney function in older adults. Individualized risk prediction tools and shared decision-making can help tailor diagnosis and management. Ultimately, moving beyond arbitrary thresholds toward a patient-centred, risk-based strategy may best serve individuals across their lifespans, ensuring that CKD diagnosis and care are both scientifically sound and clinically meaningful.