Cigarette Smoking and Risk of Hospitalization With Acute Kidney Injury: The Atherosclerosis Risk in Communities (ARIC) Study

Abstract

Rationale & ObjectiveSmoking is a modifiable risk factor for various adverse events. However, little is known about the association of smoking with the incidence of acute kidney injury (AKI) in the general population. The objective of this study is to investigate the association of cigarette smoking with the risk of AKI. Study DesignProspective observational study. Setting & Participants14,571 participants (mean age 55 [6] years, 55% women and 25% Black participants) from the ARIC study visit 1 (1987-1989) were followed through December 31, 2019. ExposuresSmoking parameters (status, duration, pack-years, intensity, and years since cessation). OutcomesIncident hospitalization with AKI, defined by a hospital discharge with a diagnostic code relevant to AKI. Analytical ApproachMultivariable Cox regression models. ResultsOver a median follow-up of 26.3 years, 2,984 participants had an incident hospitalization with AKI. Current and former smokers had a significantly higher risk of AKI compared to never smokers after adjusting for potential confounders (Hazard ratio [HR], 2.22 [95% CI: 2.02-2.45] and 1.12 [1.02-1.23], respectively). A dose-response association was consistently seen for each of smoking duration, pack-years, and intensity with AKI (e.g., 1.19 [1.16-1.22] per 10 years of smoking). When years since cessation were considered as a time-varying exposure, the risk of AKI associated with smoking, compared to current smokers, began to decrease after 10 years, and became similar to never smokers at 30 years (HR for ≥30 years, 1.07 [0.97-1.20] vs. never smokers). LimitationsSelf-reported smoking measurements and missing outpatient AKI cases. ConclusionsIn a community-based cohort, all smoking parameters were robustly associated with the risk of AKI. Smoking cessation was associated with decreased risk of AKI, although the excess risk lasted up to 30 years. Our study supports the importance of preventing smoking initiation and promoting smoking cessation for the risk of AKI.