Gout medication decreases risk of ALS and other diseases: Study
Allopurinol, carvedilol use were examined in people older than 65
Allopurinol and carvedilol, two medications respectively used to manage gout and high blood pressure, significantly reduce the chances of developing amyotrophic lateral sclerosis (ALS), Alzheimer’s, or Parkinson’s disease, a new study suggests.
“These findings suggest a possible new direction for repurposing or developing medications for neuroprotection,” Brad Racette, MD, study co-author at Barrow Neurological Institute, said in a press release.
The study, “Biologic targets of prescription medications and risk of neurodegenerative disease in United States Medicare beneficiaries,” was published in PLOS One.
ALS, Parkinson’s, and Alzheimer’s are all diseases marked by the gradual death and dysfunction of nerve cells in the brain and/or spinal cord. The specific manifestations of these three diseases differ, and their exact causes remain largely unknown. Nonetheless, it’s thought that some biological mechanisms — such as increased inflammation and cellular stressors — likely play a role in driving all of these conditions.
Here, scientists at Barrow, the Washington University School of Medicine in St. Louis, and University of Witwatersrand in Johannesburg conducted an analysis using data collected by Medicare, the U.S. government program that provides health insurance to people 65 and older, aiming to identify medications that might alter the risk of these diseases.
For the analysis, researchers looked at medications prescribed in 2006-2007, and then identified patients diagnosed with one of the three diseases in 2009.
The analysis included data on more than 370,000 people. Among them, 1,341 had ALS only, 8,332 had Alzheimer’s only, 28,679 had Parkinson’s, and 4,533 had a combination of at least two of the neurodegenerative conditions. There also were 334,387 people with comparable demographic characteristics who didn’t develop any of these diseases.
Most patients in the analysis were white, and all were older than 65. A follow-up analysis using data from 2010-2014 also was conducted to verify the results.
“In this large, population-based study, we took a unique approach to investigate the association between various medication categories in relation to the three most common neurodegenerative diseases: Alzheimer’s disease, Parkinson’s disease and amyotrophic lateral sclerosis,” said Racette, chairman of neurology and senior vice president at Barrow.
Likelihood of developing ALS, Parkinson’s, Alzheimer’s reduced in statistical models
Statistical models showed the chances of developing any of these three diseases was significantly reduced among patients who had been treated with allopurinol, which is commonly given to manage gout (a form of inflammatory arthritis characterized by joint swelling and pain). For ALS specifically, results indicated the likelihood was reduced by 13%.
The reduction was estimated at 16% for Parkinson’s and 31% for Alzheimer’s. Considering all three diseases collectively, the likelihood was reduced by 34% among patients on allopurinol.
Allopurinol works by blocking the activity of an enzyme called xanthine dehydrogenase, which reduces the production of a waste product called uric acid that drives inflammation in gout.
Results showed that another medication, carvedilol — which is used to manage blood pressure and heart disease, and can also reduce activity of the xanthine dehydrogenase pathway — also was associated with a reduced risk of these three diseases.
In particular, people taking this medication were 22% less likely to develop ALS, and the changes of having Parkinson’s or Alzheimer’s were reduced by 10%-19%. Overall, the chances of developing any of these conditions were 28% lower.
Other gout and blood pressure medications that don’t act on this pathway did not show a consistent relationship with disease risk. Collectively these findings suggest these two medications may be repurposed to prevent these conditions.
The team noted the analysis was limited by its use of insurance data from elderly patients, so the findings may not be applicable to younger populations. They also emphasized it’s impossible to draw definitive conclusions about cause and effect from these data, urging further study to investigate whether these treatments can actually reduce disease risk or whether other factors might explain these associations.
“Ultimately, further experimental and epidemiologic studies will be required to understand whether our findings are causal and related,” they wrote.
The scientists also stressed this study was assessing whether these medications affect the risk of developing these diseases, not whether the medications might change the course of the disease for people who already have it.
“The medication associations we studied relate to disease risk. Further research will be necessary to examine whether this mechanism slows progression of these diseases,” Racette said.