Kidney function and cognitive and functional decline in elderly adults: findings from the Singapore longitudinal aging study.
OBJECTIVE
To investigate whether lower estimated glomerular filtration rate (eGFR) or chronic kidney disease (CKD) was associated with subsequent cognitive and instrumental activity of daily living (IADL) decline in a prospective cohort study.


METHODS
Prospective cohort study, followed for up to 4 years.


METHODS
General community.


METHODS
One thousand three hundred fifteen adults aged 55 and older from the Singapore Longitudinal Aging Study.


METHODS
Baseline data included eGFR levels, presence of CKD (eGFR < 60 mL/min per 1.73 m(2) ), and known confounders. Cognitive decline was defined as a drop of 2 or more points on the Mini-Mental State Examination (MMSE) and functional decline as a drop of 2 or more points in IADL score.


RESULTS
Decreasing levels of eGFR and the presence of CKD were associated with greater odds of cognitive decline at follow-up independent of confounding risk factors in multivariate analyses: estimated 14% increment in odds of cognitive decline per 10 mL/min/1.73 m(2) decrease in eGFR (odds ratio = 1.94, 95% confidence interval = 1.23-3.05; P = .004 for CKD vs non-CKD). Similar associations were found in a cognitively normal subgroup (MMSE > 23) at baseline. In the whole sample, CKD, but not eGFR, was found to be significantly associated with higher risk of IADL decline.


CONCLUSIONS
CKD in older persons was significantly associated with cognitive and functional decline. Future research should target the development and evaluation of strategies to delay or prevent cognitive decline and physical disability in elderly adults with impaired kidney function.
Gerontological Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
Liang
L
Feng
Keng Bee
KB
Yap
Lee Ying
LY
Yeoh
Tze Pin
TP
Ng
D000203:Activities of Daily Living; D000368:Aged; D000369:Aged, 80 and over; D016009:Chi-Square Distribution; D003072:Cognition Disorders / Q000453:epidemiology* / Q000503:physiopathology; D005260:Female; D005500:Follow-Up Studies; D005919:Glomerular Filtration Rate; D006801:Humans; D007676:Kidney Failure, Chronic / Q000453:epidemiology* / Q000503:physiopathology; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D012846:Singapore / Q000453:epidemiology