High uric acid contributes to increased dementia risk
Elderly individuals with high levels of serum uric acid (SUA) may be at an increased risk of dementia, particularly vascular or mixed dementia, a study suggests.
Researchers assessed the longitudinal association between SUA level and incident dementia in 1,598 older adults (mean age 72.4 years; 38.3 percent male). SUA levels were also evaluated in relation to MRI markers of brain ageing such as white matter hyperintensity volume (WMHV), lacunes and hippocampal volume.
A total of 110 individuals developed dementia during the 13,357 person-years of follow-up (median duration, 10.1 years), with a crude incidence rate of 8.2 per 1,000 person-years. Individuals with the highest SUA levels were 1.7 times as likely as those with the lowest SUA levels to develop dementia (adjusted hazard ratio [HR], 1.79; 95 percent CI, 1.17 to 2.73; p=0.007).
The association between SUA level and dementia was more evident for vascular or mixed dementia (adjusted HR, 3.66; 1.29 to 10.41; p=0.015) than for Alzheimer's disease (adjusted HR, 1.55; 0.92 to 2.61; p=0.10).
A nonsignificant trend toward an association with high SUA level was observed for extensive WMHV (p=0.10), which is a biomarker of small vessel disease, but not for hippocampal volume (p=0.94) or lacunes (p=0.86).
Researchers noted that interim strokes might have an influence on the association between SUA level and vascular or mixed dementia.
Hyperuricaemia is a condition preceding gout and a potential risk factor for cardiovascular and kidney diseases. In the management of gout, maintaining too low SUA levels is a concern because uric acid (UA) is believed to be neuroprotective. The protective effect of UA is attributed to its potential important antioxidant properties, with previous studies reporting increased risk of several neurodegenerative diseases, such as Parkinson’s disease or amyotrophic lateral sclerosis, with a low SUA level. [Nat Rev Rheumatol 2014;10:654–61; Age 2016;38:16; J Neurol 2014;261:1133–8]