Moderate Alcohol Consumption Protects Against Kidney Disease
People who consume either modest, or what some may even consider not-so-modest, amounts of alcohol every week have a lower risk of developing chronic kidney disease (CKD) compared with never drinkers, and higher levels of alcohol consumption are associated with greater protection up to a limit of 20 drinks per week, according to a new analysis of the Atherosclerosis Risk in Communities (ARIC) study.
“Modest alcohol consumption has been found to be associated with lower risk of coronary heart disease (CHD) and myocardial infarction, which share similar risk factors and pathophysiology with CKD,” lead author Emily Hu, MHS, Johns Hopkins University, Baltimore, Maryland, and colleagues observe.
“Our large prospective cohort study of 12,692 blacks and whites in the United States found a significant and consistent inverse association between alcohol consumption and incident CKD…[although] for alcohol consumption > 20 drinks per week, the association was no longer statistically significant,” they add.
The study was published in the January issue of the Journal of Renal Nutrition.
Lengthy Follow-up of the ARIC Study
The ARIC study was a community-based cohort of middle-aged black and white men and women between the ages of 45 and 64 years at study enrollment.
“Alcohol consumption was assessed at visit 1 (1987-1989),” investigators note. People were asked if they currently drank alcohol and, if so, how often.
Four ounces of wine, 12 ounces of beer, or 1.5 ounces of hard liquor counted as a single drink.
Current drinkers were categorized as drinking 1 or fewer drinks per week, 2 to 7 drinks per week, 8 to 14 drinks per week, or 15 or more drinks per week.
Incident CKD was defined as an estimated glomerular filtration rate (eGFR) of less than 60 mL/min/1.73m2 accompanied by a 25% or greater decline in eGFR, kidney disease-related hospitalization or death, or development of end-stage renal disease.
Over a median follow-up of 24 years, 3664 cases of incident CKD were documented among the cohort.
In all three models used to analyze the effect that alcohol might have on CKD risk, “participants who drank alcohol had significantly lower risks of CKD compared with never drinkers,” investigators report.
No significant association was observed between CKD risk and former drinkers, they add.
In their main model, adjusted for total energy intake, age, sex, race, income, education level, health insurance, smoking, and physical activity, participants who drank 1 or fewer drinks per week had a 12% lower risk of developing CKD compared with never drinkers, while those who drank 2 to 7 drinks per week had a 20% lower risk of CKD than the same comparator group.
Participants who consumed 8 to 14 drinks per week had a 29% lower CKD risk compared with never drinkers, while those who consumed 15 drinks or more per week had a 23% lower risk of CKD, again compared with never drinkers.
Additional adjustments for potential mediators of CKD risk including diabetes, high blood pressure, body mass index, and baseline eGFR did not appreciably change these estimates, the researchers add.
In fact, “the risk of CKD per each additional drink per day after accounting for the competing risk of non-CKD death was similar to the main results,” they note.
Gender did not appear to affect the findings but the association between alcohol consumption and CKD risk appeared to be stronger among smokers than nonsmokers.
“We found that alcohol consumption ranging from 1 drink per week to 15 drinks per week was associated with lower risk of incident CKD compared with never drinkers after adjusting for confounders,” the authors emphasize.
“Moderate Consumption of Alcohol May Not Be Harmful to Kidneys”
As the authors suggest, the possible ways in which alcohol might affect CKD risk may be similar to the effect alcohol has on the risk of CHD as the two share similar pathophysiological pathways.
For example, the prevalence of diabetes was lower among current drinkers in the current study relative to never drinkers.
They note that alcohol consumption was self-reported so weekly drinking levels in the study may have been under-reported.
“Drinking habits may [also] have changed over time,” they acknowledge.
Still, they conclude that “moderate consumption of alcohol may not likely be harmful to the kidneys.”
However, they stress that the Global Burden of Disease Study suggests even low alcohol consumption may be associated with an increased global disease burden.
“Therefore, our findings must be considered in the context of all the potential benefits and harms of alcohol,” they conclude.
The authors have reported no relevant financial relationships.
J Ren Nutr. 2020;30:22-30. Abstract