Alcohol use disorder is associated with higher risks of Alzheimer's and Parkinson's diseases: A study of US insurance claims data

INTRODUCTION: Alcohol use disorder (AUD) is on the ascendancy in the US older adult population. The association between AUD and adverse brain outcomes remains inconclusive. METHOD: In a retrospective cohort design using US insurance claim data (2007–2020), 129,182 individuals with AUD were matched with 129,182 controls by age, sex, race, and clinical characteristics. We investigated the association between AUD and adverse brain outcomes using Cox analysis, Kaplan–Meier analysis, and log‐rank test. RESULTS: After adjusting for covariates, AUD was associated with a higher risk of Alzheimer's disease (female adjusted hazard ratio [HR] = 1.78, 95% confidence interval [CI]: 1.68–1.90, p < 0.001; male adjusted HR = 1.80, 95% CI: 1.71–1.91, p < 0.001) and a higher risk of Parkinson's disease (female adjusted HR = 1.49, 95% CI: 1.32–1.68, p < 0.001; male adjusted HR = 1.42, 95% CI: 1.32–1.52, p < 0.001) in the overall sample. In separate analyses of Black, White, and Hispanic individuals, those with AUD had higher risk of Alzheimer's disease (adjusted HRs ≥1.58; Ps ≤ 0.001). A significantly elevated risk for Parkinson's disease was found only in the White subpopulation (female adjusted HR = 1.55, 95% CI: 1.36–1.77, p < 0.001; male adjusted HR = 1.45, 95% CI: 1.33–1.57, p < 0.001). CONCLUSIONS: AUD is associated with Alzheimer's disease. AUD is associated with Parkinson's disease in White people. Cognitive screening and neurological examination among older adults with AUD hold the promise for early detection of Alzheimer's disease and Parkinson's disease. HIGHLIGHTS: Alcohol use disorder is associated with Alzheimer's disease and dementia. Alcohol use disorder is associated with Parkinson's disease in White people.