Relationship between acute kidney injury, seasonal influenza, and environmental factors: A 14-year retrospective analysis

• Published in: Environment international Vol. 153; p. 106521
• Main Authors: Mohammad, Kirran N., Chan, Emily Ying Yang, Lau, Steven Yuk-Fai, Lam, Holly Ching Yu, Goggins, William Bernard, Chong, Ka Chun
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Ltd 01.08.2021; Elsevier
• Subjects: Acute kidney injury; Air pollution; Ambient temperature; China; confidence interval; Distributed-lag non-linear model; influenza; influenza vaccination; monitoring; nitrogen dioxide; nonlinear models; ozone; rain; relative humidity; relative risk; retrospective studies; risk factors; Seasonal influenza; Subtropics; temperature; China; Seasonal influenza; Air pollution; Distributed-lag non-linear model; Ambient temperature; Acute kidney injury; Subtropics
• DOI: 10.1016/j.envint.2021.106521
• ISSN: 0160-4120; 1873-6750

•Moderate-to-high levels of nitrogen dioxide were associated with AKI events.•Positive association between seasonal influenza activity and AKI events.•Risk of AKI increased when the temperature was low.•Officials are urged to extend influenza vaccination program to individuals with pre-existing renal conditions.•Adopting clean-air policies to protect the health of the community is recommended. Despite high incidence of acute kidney injury (AKI) among patients hospitalised for influenza, no previous work has attempted to analyse and quantify the association between the two. Herein, we made use of Hong Kong's surveillance data to evaluate the time-varying relationship between seasonal influenza and risk of AKI with adjustment for potential environmental covariates. Generalized additive model was used in conjunction with distributed-lag non-linear model to estimate the association of interest with daily AKI admissions as outcome and daily influenza admissions as predictor, while controlling for environmental variables (i.e. temperature, relative humidity, total rainfall, nitrogen dioxide, and ozone). Results suggested a positive association between risk of AKI admission and number of influenza hospitalisation cases, with relative risk reaching 1.12 (95% confidence interval, 1.10–1.15) at the 95th percentile. Using median as reference, an almost U-shaped association between risk of AKI admission and temperature was observed; the risk increased significantly when the temperature was low. While ozone was not shown to be a risk factor for AKI, moderate-to-high levels of nitrogen dioxide (50–95th percentile) were significantly associated with increased risk of AKI admission. This study mentioned the possibility that AKI hospitalisations are subject to environmental influences and offered support for a positive association between seasonal influenza and AKI occurrence in Hong Kong. Authorities are urged to extend the influenza vaccination program to individuals with pre-existing renal conditions to safeguard the health of the vulnerable. Given that adverse health effects are evident at current ambient levels of nitrogen dioxide, the government is recommended to adopt clean-air policies at the earliest opportunity to protect the health of the community.