Alcohol consumption in the elderly and risk of dementia related death - a Norwegian prospective study with a 17-year follow-up

Purpose: The aim of this study was to determine the association between alcohol intake and risk of dementia related death, taking into account relevant confounding and mediating factors. Materials and Methods: Data was obtained from a Norwegian prospective study with a 17-year follow-up. The study population comprised 25,635 participants aged between 60 and 80 years at the time of examination from the Cohort of Norway (CONOR). Cox regression was used to investigate the association between alcohol use and dementia related death. Results: Nearly half (12,139) of the study population died during follow-up, of which 1,224 had a diagnosis of dementia on their death certificate. The risk of dementia related death was significantly higher among abstainers than among individuals that drank alcohol once per month (HR = 1.33, 95% CI = 1.14–1.56, p < 0.001, in a fully adjusted model). Respondents with missing information regarding alcohol consumption (representing 5% of the study population) had the highest risk of dementia related death (HR = 1.60, 95% CI = 1.28–2.00, p < 0.001) and also significantly higher mortality rates due to alcohol-related causes (HR = 1.41, 95% CI = 1.03–1.93, p = 0.031) and other causes (HR = 1.32, 95% CI = 1.21–1.43, p < 0.001), all compared to those drinking alcohol no more than once per month. Conclusion: These findings suggest that the risk of dementia related death is significantly higher among elderly abstainers than among those who drink alcohol, after adjusting for relevant confounders. However, care should be taken in interpretation of data due to missing information on drinking frequency, as this missing-group might have a large share of the heavy drinkers in the study cohort.