Possible effect of Allopurinol and risk of dementia: An updated Meta-Analysis

Background: Allopurinol is frequently prescribed medication for treatment of hyperuricemia and gout, due to its uric acid lowering capacity with inhibition of xanthine oxidase in the body. However, the side effects of long term allopurinol use among gout patients, particularly related to dementia and cognitive health is not well understood. Aims & Objectives: This meta-analysis based study aimed to provide an updated and robust assessment of relationship among the long term use of allopurinol and risk of dementia. Methods: The “Reporting Items for Systematic Review and Meta-Analysis (PRISMA)" guidelines were followed in this study for screening and selection of research articles. Three electronic databases named PubMed, MEDLINE, and Cochrane library were used for data extraction. The primary outcomes of this study were hazard ratio or odds ratio of association of allopurinol exposure and dementia risk among gout patients. The Newcastle-Ottawa Scale (NOS) was applied for quality assessment of observational studies. The RevMan 5.3 software was used for statistical analysis of data from studies included in this study. Results: About 650 research articles were extracted from three electronic databases after applying the above-mentioned search strategy and the final number of research articles after applying exclusion criteria was 9. Among 9 included studies, four studies were of low risks, four studies were of moderate risks and one study was high risk. Through nine prospective cohort studies, and 1462 to 1710000 patients, the findings of study reported that that exposure of allopurinol is slightly significant as it triggers the risk of dementia among cases as compared to control [RR: 2.28 (95% Cl 2.00, 2.60)] and heterogeneity reported (df =8, p=1.00, I2=0). Conclusion: Overall, the findings of our study reported a slightly significant association between allopurinol exposure and an increased risk of dementia. This suggests that long-term use of allopurinol may be associated with a higher risk of developing dementia in patients with gout or hyperuricemia.