Renal function and decline in functional capacity in older adults.

Area of Science:

• Gerontology
• Nephrology
• Public Health

Background:

• The longitudinal relationship between renal function, disability, and mortality in older adults remains under-explored.
• Understanding these interconnections is crucial for developing targeted interventions.

Purpose of the Study:

• To investigate the temporal association between renal function and disability in older Koreans.
• To determine how disability influences mortality based on varying levels of renal function.

Main Methods:

• Utilized data from the Korean Longitudinal Study on Health and Aging, a prospective, population-based cohort.
• Included community-dwelling Koreans aged 65 and older.
• Assessed activities of daily living (ADL), instrumental activities of daily living (IADL), and all-cause mortality over a 5-year period.

Main Results:

• A total of 984 participants were followed; 70.9% participation rate.
• Participants were grouped by baseline estimated glomerular filtration rate (eGFR): Group I (≥60), Group II (45-59), and Group III (<45 ml/min/1.73 m²).
• Decline in renal function was associated with a higher incidence of ADL/IADL decline (29.5%, P = 0.01).
• IADL disability significantly increased mortality risk (HR 1.87 in Group I, HR 2.53 in Groups II/III) after adjustment.

Conclusions:

• Impaired renal function is significantly associated with disability and decline in ADL/IADL.
• The detrimental effect of ADL/IADL disability on mortality is more pronounced in individuals with reduced estimated glomerular filtration rates (eGFR).