Association Between Alcohol Consumption and the Risk of Incident Chronic Kidney Disease: A Korean Nationwide Study of Community-Dwelling Older Adults

Background/Objectives: This study examined the effects of alcohol consumption on chronic kidney disease (CKD) risk in community-dwelling older adults. Methods: A nationwide retrospective observational study was conducted using NHIS-Senior cohort data (2009–2018). Adults aged ≥ 65 years with an estimated glomerular filtration rate (eGFR) ≥ 60 mL/min/1.73 m² were included. Alcohol consumption was classified as non-drinking, mild, moderate, or heavy drinking. CKD onset was defined as eGFR < 60 mL/min/1.73 m². Results: Of the 122,319 subjects, the non-, mild, moderate, and heavy drinking groups comprised 99,091 (81.0%), 14,842 (12.1%), 4257 (3.5%), and 4139 (3.4%), respectively. During follow-up, 19,796 (20.0%), 4636 (31.2%), 1696 (39.8%), and 1695 (41.0%) patients developed CKD in the non-, mild, moderate, and heavy drinking groups, respectively. Univariate Cox regression analyses showed a significantly increased risk of incident CKD in all drinking groups compared with non-drinkers (all p < 0.001). However, hazard ratios (HR) for developing CKD were 0.90 (95% confidence interval [CI] 0.87–0.94, p < 0.001) for mild, 0.89 (95% CI 0.84–0.95, p < 0.001) for moderate, and 0.93 (95% CI 0.88–0.99, p = 0.027) for heavy drinkers. In subgroup analysis, the beneficial effect of alcohol consumption on incident CKD was prominent among moderate drinkers aged 65–74 years and mild drinkers aged ≥ 75 years, in males and mild drinkers aged < 85 years in females. Conclusions: This study shows that alcohol consumption is negatively associated with the risk of incident CKD in older adults, particularly among males.