Alzheimer's & Dementia: Alcohol use disorder is associated with a higher risk of Alzheimer's disease and Parkinson's disease

Data from the 2017 to 2019 National Survey showed that (1) more than 40 percent of older Americans drank alcohol, and (2) more than 13 percent of older Americans drank heavily or
excessively.
From 2001–2002 to 2012–2013, the prevalence of alcohol use disorder (AUD) among older adults increased 1.
75-fold (p <0.
05
) from 3.
2% (95% CI: 2.
6% to 4.
0%) to 5.
6% (95% CI: 4.
8% to 6.
6%).

Although excessive alcohol consumption is known to have neurotoxic consequences, population-based association studies investigating adverse brain outcomes for alcohol consumers and/or people with AUD have had mixed results
.
An analysis of 31.
6 million French patients found that AUD was associated with
an increased risk of dementia, including Alzheimer's disease.
Based on the above research and literature review, the 2020 report of the Lancet Commission on Dementia Prevention, Intervention and Care concluded that excessive alcohol consumption (>21/week) is a new risk factor
for dementia.
AUD was also associated with an increased risk of Parkinson's disease (HR = 1.
38, p < 0.
001
) among 602,930 Swedish patients with a mean follow-up of 13 years.
In addition, an observational study conducted in the UK over 30 years concluded that moderate and heavy alcohol consumption (i.
e.
, 14-21 and >21/week) increased the risk of developing hippocampal atrophy (odds ratio [ORs] >3.
, Ps≤0.
007).

On the other hand, some studies have found that alcohol consumption and AUD are not associated or associated with a reduced risk of degenerative brain disease.

A 3-year observational study conducted in Germany found that drinkers reduced the risk
of dementia overall (HR = 0.
71, p = 0.
028) and Alzheimer's disease (HR = 0.
58, p = 0.
013).
A cohort study of middle-aged and older adults in the United States (N = 19,887) concluded that there was a U-shaped relationship between weekly drinking and cognitive function, with 10-14 drinks per week drinking better
cognitive function.
Another 13-year large cohort study in the US (N = 132,403) found no association
between alcohol consumption and Parkinson's disease risk.
The relationship between AUD and adverse brain outcomes remains uncertain
.

Pengyue Zhang et al.
conducted a retrospective cohort study using U.
S.
insurance claims data (2007-2020), in which 129,182 AUD patients were matched
with 129,182 controls by age, sex, race, and clinical features.
Cox analysis, Kaplan-Meier analysis, and log-rank tests were used to investigate the relationship
between AUD and poor brain outcomes.

Figure 2.
( A) Association of alcohol use disorder with Alzheimer's disease in multivariate Cox analysis (N = 258,364).

(B) Association of alcohol use disorder with Parkinson's disease in multivariate Cox analysis (N = 258,364).

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 to 1.
90, p<0.
001; Adjusted HR = 1.
80 for men, 95% CI: 1.
71 to 1.
91, p<0.
001) and higher risk of Parkinson's disease (adjusted HR = 1.
49, 95% CI: 1.
32 to 1.
68, p <0.
001; Male adjusted HR = 1.
42, 95% CI: 1.
32 to 1.
52, p <0.
001).

Figure 3.
Cumulative incidence of Alzheimer's disease after index date in individuals with alcohol use disorder and matched controls; (A) white subpopulation (female N = 68,460, male N = 119,808) ;(B) Spanish subpopulation (7210 females, 20442 males) ;(C) Black subpopulation (females N = 8294, males N = 15,234) ;(D) Asian subpopulation (females 1352, males 3304)

Figure 4.
Cumulative incidence of Parkinson's disease after index date in individuals with alcohol use disorder and matched controls; (A) white subpopulation (female N = 68,460, male N = 119,808) ;(B) Spanish subpopulation (female 7210, male 20442) ;(C) black subpopulation (female N = 8294, male N = 15,234) ;(D) Asian subpopulation (female 1352, male 3304)

In separate analyses of black, white, and Hispanic individuals, patients with AUD had a higher risk of Alzheimer's disease (adjusted HR≥ 1.
58; Ps≤0.
001)
。 A significantly increased risk of Parkinson's disease was found only in the white subgroup (female-adjusted HR = 1.
55, 95% CI: 1.
36 to 1.
77, p < 0.
001; Male-adjusted HR = 1.
45, 95% CI: 1.
33 to 1.
57, p <0.
001).

Together, the study found that AUD was associated with
an increased risk of Alzheimer's disease and Parkinson's disease across the study population.
In the black subgroup, AUD was associated with the highest risk of Alzheimer's disease, followed by the white subpopulation and the Hispanic subpopulation
.
In the white subgroup, AUD was associated with
an increased risk of Parkinson's disease.
Women with AUD have a higher or comparable
risk of adverse brain outcomes compared to people with AUD.

Original source

Alcohol use disorder is associated with higher risks of Alzheimer's and Parkinson's diseases: A study of US insurance claims data.
21 November 2022.
https://doi.
org/10.
1002/dad2.
12370