The extreme pain of gout may have its bright side. New research suggests that people with acute inflammatory gouty arthritis have a lower risk of developing Alzheimer’s disease (AD) relative to those without gout. “We found a potentially protective effect of gout on reducing the risk of developing AD and provide the first population-based evidence to support a neuroprotective effect of uric acid,” said Hyon Choi, M.D., P.H., and senior investigator of the study, who serves as Massachusetts General Hospital’s director of epidemiology at Massachusetts General Hospital.
With data from the Health Promotion Network data and a representative electronic medical record database of the total U.K. population, Choi and his colleagues included 59,224 gout patients (including 70.8 percent men, mean age 65.3 years) and 238,805 gout-free controls (including 71.1 percent men, mean age 65.3 years) matched for age, sex, body mass index, study entry date and enrollment time. mean age 65.3 years).
The study obtained their gout diagnosis, prognosis, and risk factors for dementia from electronic medical case records. During a mean follow-up of 5.1 years, the study found 309 new AD cases in the gout group compared with 1,942 in the control group, and the study showed an incidence of AD of 1 per 1,000 person-years in the gout group compared with 1.5 per 1,000 person-years in the control group, said Choi, who announced the results at the annual American College of Rheumatology.
After adjusting for body mass index (BMI), smoking, alcohol consumption, preexisting conditions and cardiovascular medications, patients with gout had a multifactorial risk ratio for AD of 0.76 (95%, confidence interval 0.66 to 0.87), a 24% reduction in the risk of AD compared with controls without gout.
Prior to this, there were no studies demonstrating an association between gout and AD risk, but Choi noted that data from the Rotterdam Elderly Study, published in the 2009 issue of Brain, showed an inverse relationship between serum uric acid levels and the risk of any dementia. Specifically, Brain reported findings that for each standard deviation increase in serum uric acid levels over 11 years of follow-up, there was an 11% reduction in the risk of any type of dementia (ratio of 0.89, 95% confidence interval 0.80 to 0.99).
In addition, he explained, higher serum uric acid levels at baseline correlated with improved self-cognitive function later in life. While the underlying biological mechanisms behind this correlation, i.e., the correlation between uric acid and self-perception of health, still need to be reasoned with further research, uric acid has been shown to have antioxidant properties and has been shown to prevent oxidative stress-induced dopaminergic neuronal death in animal models.