Renal biomarker in older adults linked to higher risk of cognitive decline and dementia, new analysis of ASPREE data shows
Dementia is the second leading cause of death in Australia, and the leading cause of death in women. With the path to diagnosing dementia often delayed, comes a lost opportunity for early healthcare to help individuals manage the disease. Now, a new analysis of ASPREE data suggests a routine urine test for kidney disease may be key to closing the gap, to help doctors identify healthy older adults at risk.
In the largest study of its kind, ASPREE researchers from Monash University and the Berman Center for Outcomes and Clinical Research in Minnesota, U.S., investigated whether biomarkers for kidney disease helped identify older adults at risk of cognitive impairment and dementia.
Chronic Kidney Disease (CKD) is a recognised risk factor for cognitive impairment.
Researchers examined two commonly used biomarkers for CKD in 18,131 participants in the ASPREE trial in Australia and the U.S:
- Albuminuria – the abnormal leakage of the protein Albumin in the urine;
- and eGFR (estimated glomerular filtration rate) – an estimate of how well kidneys are removing waste from the blood.
Previous research linked Albuminuria and eGFR to structural and microvascular (tiny blood vessels) changes in the brain.
In this analysis researchers found only one CKD biomarker, albuminuria, was significantly associated with changes in cognitive function and dementia in ASPREE participants.
Abnormal high levels of albumin in the urine (UACR ≥ 3 mg/mmol) recorded at study entry were associated with having a lower cognitive function at that timepoint, as well as a higher future risk of developing cognitive impairment and dementia.
Lead author, Prof Anne Murray said study findings indicated that testing for mild levels of albuminuria could be used to identify those at higher risk of cognitive impairment and dementia in older adults that do not have advanced kidney or heart disease.
ASPREE participants were generally in good health and living independently at enrolment into the study. They did not have evidence of heart disease, severe CKD, persistent physical disability or dementia. Individuals with high blood pressure and diabetes could enrol in the ASPREE, provided these conditions were well controlled.
The average age of participants was 74 years.
The eGFR biomarker did not show an association with changes in cognition compared to albuminuria.
Study participants provided blood and urine samples to pathology centres at study entry and regularly undertook a suite of cognitive measures during an average 4.7 years of follow-up. Over the course of the ASPREE trial, 2,777 participants experienced a consistent decline in cognitive function, with 563 participants diagnosed with dementia.
Every case of dementia was independently verified by clinical experts.
Prof Murray said early identification of cognitive impairment and those at risk of dementia enables prompt treatment to decrease negative outcomes for the patient. “We can identify those more likely to have medication and management plan adherence difficulties, who would benefit most from caregiver support,“ she added.
This paper was published in medical journal Kidney 360.