Association between alcohol consumption and mortality in Parkinson's disease

Previous studies on the association between alcohol consumption and risk of Parkinson's disease (PD) have produced controversial results. However, the relationship between alcohol consumption and mortality in PD has scarcely been investigated. Among the nationwide population data from Korea National Health Insurance Service, newly diagnosed PD (ICD-10 code: G20 and a rare intractable disease registration code: V124), between 2009 and 2017, were selected. Alcohol consumption habit was obtained from a self-reported questionnaire on the National Health Screening Program. 32,419 individuals with PD were followed-up longitudinally until December 31, 2017, and all-cause mortality was evaluated. During the follow-up period (mean 4.37 ± 2.67 years), 9,049 deaths occurred. When nondrinkers are used as a reference group, there were significant associations between alcohol consumption and all-cause mortality in mild (hazard ratio [HR] 0.78, 95% confidence interval [CI] 0.71-0.84) and moderate drinkers (HR 0.69, 95% CI 0.58-0.82), but not in heavy drinkers (HR 0.84, 95% CI 0.69-1.02). In the sensitivity analysis using never drinkers as the reference group, the results also showed an overall 20% reduced mortality risk among drinkers with PD. Regarding changes in alcohol consumption behavior before and after diagnosis, the mortality rate was higher in former drinkers (HR 1.20, 95% CI 1.02-1.41) and lower in constant drinkers (HR 0.74, 95% CI 0.65-0.83) than in never drinkers. Alcohol consumption appears to be associated with reduced all-cause mortality in PD, suggesting potential neuroprotective effects on disease progression. Although drinking does not appear to be detrimental to all-cause mortality in individuals with PD, alcohol consumption in PD requires attention considering individual motor and non-motor symptoms. Future studies in other ethnic groups are warranted to validate the association between alcohol consumption and disease progression, including mortality, in PD.