Researchers have found evidence suggesting a blood test to measure uric acid, which indicates kidney function, could help assess the risk of impaired cognitive function in old age.
Scientists from John Hopkins and Yale University medical schools found older people with high uric acid levels were more likely to have difficulty processing, storing and recounting information.
High to normal uric acid levels were defined in the study as 5.8 to 7.6 mg for men and 4.8 to 7.1 mg for women.
Lead author David Schretlen said: "It might be useful for primary-care physicians to ask elderly adults with high normal serum uric acid about any problems they might be having with their thinking, and perhaps refer those who express concern, or whose family members express concern, for neuropsychological screening."
Uric acid levels increase with age, and the authors said the findings were surprising because the substance has antioxidant properties thought to be protective in some situations.
The research was based on 96 people aged between 60 and 92 and appears in the January issue of Neuropsychology.