Gout May Protect Against Alzheimer's

by Kate Johnson for MedPage Today:There may be a bright side to the excruciating pain of gout.New research suggests that patients diagnosed with this acute inflammatory arthritis face a lower risk of developing Alzheimer's disease (AD) compared with people without gout."Our findings provide the first population-based evidence for the potential protective effect of gout on the risk of AD, and support the neuroprotective role of uric acid," said Hyon Choi, MD, DrPH, the study's senior investigator, and director of epidemiology at Massachusetts General Hospital here.Using data from The Health Improvement Network (THIN), an electronic medical records database representative of the U.K. general population, Choi and his colleagues identified 59,224 individuals with gout (70.8% male, mean age 65.3 years) and matched them to 238,805 controls without gout (71.1% male, mean age 65.3 years) based on age, sex, body mass index, date of study entry, and year of enrollment.Gout diagnoses, outcomes, and dementia risk factors were identified from electronic medical records.Over a median follow-up time of 5.1 years the study identified 309 new cases of AD in the gout group and 1,942 cases in the control group, showing an incidence rate of AD in the gout group of 1.0 per 1,000 person-years compared to 1.5 per 1,000 person-years in the comparison cohort, said Choi, who presented the results at the annual meeting of the American College of Rheumatology.After adjusting for BMI, smoking, alcohol use, prior comorbid conditions, and cardiovascular drugs, the multivariate hazard ratio of AD among those with gout was 0.76 (95% CI 0.66 to 0.87), translating to a 24% lower risk of AD among people with a history of gout compared to those without.No previous studies have examined the association of gout and AD risk, but Choi pointed out that data from the Rotterdam Elderly Study, published in Brain in 2009, showed an inverse association between serum uric acid levels and the risk of any dementia.Specifically, the Brain study reported an 11% lower risk of any type of dementia per standard deviation increase in serum uric acid levels (odds ratio 0.89, 95% CI 0.80-0.99) over an 11-year follow-up period.Furthermore, higher serum uric acid levels at baseline were associated with better cognitive function later in life, he explained.While the potential biological mechanisms behind this association of uric acid and cognitive health are still speculative, uric acid has proven antioxidative properties and has been shown in animal models to protect against oxidative stress-induced dopaminergic neuron death, he said."There are several ongoing studies to prevent progression of Parkinson's disease using uric acid-raising drugs. If confirmed by future studies, similar investigations may be warranted for AD," he said.Source: http://bit.ly/1tc3nA2