Alcohol use disorders are the strongest modifiable risk factors for onset of all types of dementia, especially early-onset dementia, according to a study published in Lancet Public Health.
Michaël Schwarzinger, PhD, from the Transitional Health Economics Network in Paris, and colleagues, analyzed a nationwide retrospective cohort of adult patients aged 20 years and older admitted to a hospital in metropolitan France between 2008 and 2013 to examine the association between alcohol use disorders and dementia risk. Dementia onset was defined by the age at first dementia diagnosis recorded from 2008 to 2013; diagnoses made before age 65 years were classed as early-onset dementia. Dementia onset was separated into 3 categories: alcohol-related brain damage; vascular dementia; and other dementia, including Alzheimer's disease.
Alcohol use disorders were identified in 2 categories: any mental and behavioral disorders due to former or current chronic, harmful use of alcohol, including alcohol abstinence; or chronic diseases attributable to alcohol use disorders. Alcohol-related conditions included Wernicke-Korsakoff syndrome, end-stage liver disease and other forms of liver cirrhosis, epilepsy, and head injury. Associations of alcohol use disorders and other risk factors with dementia onset were analyzed in multivariate Cox models among patients admitted to the hospital in 2011 to 2013 with no record of dementia from 2008 to 2010.
Of 31,624,156 adults discharged from French hospitals from 2008 to 2013, 1,328,191 (4.2%) were diagnosed with dementia. A total of 720,215 (64.9%) of the 1,109,343 dementia cases were women. The proportion of women increased with age at dementia onset. Conversely, 37,233 (64.9%) of the 57,353 (5.2% of total) early-onset dementia cases were men.
A total of 945,512 (3.1%) of 30,558,137 adults were discharged with alcohol use disorders (712,583 [5.5%] of 12,941,788 men and 232,929 [1.3%] of 17,616,349 women), of whom 816,160 (86.3%) qualified for alcohol dependency and 140,312 (14.8%) had at least one period of alcohol abstinence in 2008 to 2013. Alcohol-related brain damage was recorded in 35,034 dementia cases and other alcohol use disorders in 52,625 cases. Both conditions were more frequently recorded in men (26,084 [74.5%] and 35,006 [66.5%], respectively) and accounted for 32,453 (56.6%) of 57,353 early-onset dementia cases (22,338 [38.9%] and 10,115 [17.6%], respectively).
Alcohol use disorders were the strongest modifiable risk factor for dementia onset, with an adjusted hazard ratio of 3.34 for women and 3.36 for men. Alcohol use disorders remained associated with dementia onset for both sexes in sensitivity analyses on dementia case definition (including Alzheimer's disease) or older study populations. Also, alcohol use disorders were significantly associated with all other risk factors for dementia onset.