A recent study published in the Journal of Glaucoma and led by a group of Japanese researchers evaluated the association between alcohol consumption patterns and glaucoma prevalence.
Give me some background first.
A previous study reported a deleterious link between alcohol consumption and glaucoma development but recommended further validation studies due to the heterogeneity of its evidence base.
Now, talk about the study.
In this case-control study, investigators assessed the responses to questions on drinking habits and lifestyle choices of 3,207 cases with glaucoma and the same number of matched controls.
The research team obtained detailed accounts of patient alcohol consumption patterns, including drinking frequency (never, former, a few days/week, and almost every day/week) average daily drinks, and total lifetime drinks, as well as confounding factors such as smoking history and lifestyle-related comorbidities.
Who was included in the study?
Patient data was extracted from the Inpatient Clinico-Occupational Database of the Rosai Hospital Group (ICOD-R), a nationwide, multicenter hospital-based inpatient registry database throughout Japan.
Patients over the age of 40 were included from over 1.6 million patients who were admitted to 34 hospitals in Japan.
Findings?
In terms of drinking frequency, an association with glaucoma was reported for the responses:
- “A few days/week” (odds ratio [OR] 1.19, 95% confidence interval [CI] 1.03-1.38)
- “Almost every day/week” (OR 1.40, 95% CI 1.18-1.66)
Tell me more.
Of note, average daily drinks showed an association with glaucoma for “>0-2 drinks/day” (OR 1.16, 95% CI 1.03-1.32).
When it came to total lifetime drinks, a link with glaucoma was reported for:
- “>60-90 drinks/year” (OR 1.23, 95% CI 1.01-1.49)
- “>90 drinks/year” (OR 1.23, 95% CI 1.05-1.44)
How did gender impact alcohol consumption?
Among men, the drinking frequency responses that correlated with glaucoma included “a few days/week” and “almost every day/week.”
Further, in regards to average daily and lifetime drinks in men, “>0-2 drinks/day” and “>2-4 drinks/day” as well as “>60-90 drinks/year” and >90 drinks per year” had an association with glaucoma, respectively.
What about women?
Interestingly, among women, drinking frequency, average daily drinks, and total lifetime drinks were not associated with glaucoma.
The results for men were more robust than women, with the ORs for glaucoma prevalence being more significant; meanwhile, the results for women were not statistically significant.
Expert opinion?
According to the study authors, “Especially among women, the alcohol consumption reported in surveys tends to be less than actual consumption, introducing a potential information bias that could skew the results.”
Anything else?
First to note: Acetaldehyde is a metabolite of alcohol that impairs mitochondrial function, and aldehyde dehydrogenase-1 (ALDH2) alleviates cellular damage caused by alcohol by metabolizing acetaldehyde.
The researchers hypothesized that because “Asians have genetic mutations in ALDH2 more frequently than other races … low ALDH2 activity in Asians could lead to vulnerability to acetaldehyde.”
Go on…
Also to note: For people with a low capacity to metabolize acetaldehyde, alcohol is associated with intraocular pressure (IOP) elevation.
As such, the authors concluded that acetaldehyde may be an indirect to glaucoma.
“If acetaldehyde affects glaucoma, it is reasonable that alcohol consumption is strongly associated with glaucoma in Asian populations that metabolize acetaldehyde less effectively,” they added.
Limitations?
As data on diet, exercise, IOP, and visual field tests were not collected, these confounding factors and the level of glaucoma progression, respectively, were unknown.
Additionally, the validity of the findings in women was weakened by the small sample size of women with high alcohol exposure.
Take home.
The findings from this study demonstrate that alcohol has a dose-dependent effect on glaucoma in both drinking frequency and quantity.
Due to the considerable differences between men and women in the association of glaucoma with drinking frequency and alcohol consumption, future research focusing on gender differences is warranted.