[Age-related decline in renal function Physiological aging or chronic kidney disease ?]

Area of Science:

• Nephrology
• Gerontology
• Pathology

Background:

• Kidneys exhibit structural and functional aging, evidenced by imaging and microscopic changes.
• A declining glomerular filtration rate (GFR) is a hallmark of kidney aging.
• Chronic kidney disease (CKD) is diagnosed when GFR is persistently below 60 ml/min/1.73m² for over three months.

Purpose of the Study:

• To evaluate whether age-related decline in GFR is inherently linked to adverse health consequences.
• To propose an age-adapted definition for CKD.
• To advocate for individualized patient management based on prognosis rather than a fixed biological threshold.

Main Methods:

• Review of morphological, clinical, and epidemiological data concerning kidney aging.
• Analysis of the association between age-related GFR decline and adverse outcomes.
• Comparative analysis of current CKD diagnostic criteria versus a proposed age-adapted definition.

Main Results:

• Data indicate that the decline in GFR with age is not intrinsically associated with adverse health consequences.
• A significant proportion of the elderly population meets the current criteria for CKD solely due to age-related GFR reduction.
• Current CKD definitions may overdiagnose kidney impairment in the elderly.

Conclusions:

• The decline in GFR observed with aging does not necessarily equate to pathological kidney disease or predict adverse outcomes.
• An age-adapted definition of CKD is warranted to differentiate between normal aging and true kidney pathology.
• Individualized prognostic assessment is crucial for managing elderly patients with reduced GFR, moving beyond arbitrary diagnostic cutoffs.