Older adults with high levels of uric acid are more likely to experience mild loss of memory than those with low-moderate concentrations. Researchers from the Johns Hopkins University Hospital, Baltimore found that among possible markers of age-related cognitive decline (loss of memory, language, attention, reasoning, judgment, reading and writing skills), uric acid is controversial. On one hand, uric acid has antioxidant properties, which inhibits cell damage, while on the other hand, it is often elevated in diseases that frequently lead to cognitive impairment. The researchers studied 96 community-dwelling adults between the ages of 65 and 92 years who underwent physical and neurological examinations, psychiatric interviews, laboratory blood studies, MRI brain scans, and neuropsychological testing. Blood levels of uric acid among the women ranged from 1.5 to 7.1 mg/dL. For men, levels ranged from 1.5 to 7.6 mg/dL. Subjects with mildly elevated (but normal) uric acid - greater than 5.8 mg/dL for men or greater than 4.8 mg/dL for women were significantly more likely to have a below-average performance on cognitive scores. This included having nearly 6-times the likelihood impaired processing speed; 3.5-times for working memory; and 2.7 times for verbal learning and memory. After the researchers corrected the data for possible overestimation by adding in the potential effects of age, sex, race, years of education, and self-reported hypertension, diabetes, smoking, and history of alcohol abuse or dependence, they found that high blood levels of uric acid remained associated with increased risk of below average performance on measures of working memory (4.25-times) and verbal learning/memory (5.02-times). The findings might justify a clinical trial of an agent that blocks xanthine oxidase, an enzyme involved in uric acid formation, to see if it improves cognitive performance in elderly people with high uric acid levels.
Neuropsychology,
January 2007