Effects Of Air Pollutants And Meteorological Factors On Kawasaki Disease And The Occurrence And Regression Of Its Coronary Artery Lesions

Objective:Kawasaki disease（KD）is an acute and systemic vasculitis of unknown etiology,and the triggering role of environmental factors in its occurrence and development has attracted widespread attention.This study aimed to evaluate the effects of air pollutants and meteorological factors on KD and the occurrence and regression of its coronary artery lesions（CALs）,intending to provide Gansu evidence for the etiological study of KD,as well as a scientific basis for the prevention,treatment and long-term management of KD.Methods:Inpatients with KD who were admitted to the Department of Pediatric Cardiology of Lanzhou University Second Hospital from June 2015 to December 2020were selected as the research subjects.The medical record information during the patients’hospitalization and follow-up was obtained by consulting the hospital’s electronic medical record system.The air pollutants and meteorological data of monitoring stations in cities and prefectures of Gansu Province during the same period were collected from the National urban air quality real-time publishing platform of China National Environmental Monitoring Centre and the China Meteorological Data Service Centre.All individual exposure assessments were completed using Arc GIS10.8.1 according to the patient’s home address.（1）A time-stratified case-crossover study was used to evaluate the associations between air pollutants,meteorological factors,and KD on the previous 0-2 days before disease onset through conditional logistic regression,and subgroup analysis was conducted according to sex,age,and season.（2）All research subjects were divided into Kawasaki disease complicated with coronary artery lesion and Kawasaki disease without coronary artery lesion group based on echocardiographic results.The unconditional logistic regression and Bayesian kernel machine regression were fitted to assess the individual and joint effects of air pollutants and meteorological factors on CAL,respectively,and to explore their dose-response relationship.（3）Patients who were found to have CAL within 8 weeks of the KD course were conducted strictly followed up.The Kaplan-Meier curve method was used to estimate the overall regression time of CAL,and Cox proportional hazards regression model was used to assess the effects of air pollutants and meteorological factors on CAL regression.The restricted cubic spline was used to explore the dose-response relationship.Results:（1）A total of 479 KD patients were enrolled in the study as research subjects,and the cases were from 14 cities and prefectures in Gansu Province.Among them,there were 327 males,152 females,437 Han descent,and 42 ethnic minorities,with 89.98%of the patients being children under 5 years old.Based on echocardiographic findings,CAL was observed in 37.58%of KD patients and noncoronary cardiac abnormalities in 47.18%.In addition,during the study period,the average annual growth rate of KD was 18.33%,and the incidence of CAL was maintained at about 37%.KD can occur throughout the year,with summer and winter being the high-incidence seasons.（2）The PM₁₀ concentration in air pollutants was positively associated with the risk of KD,with each 10mg/m³ increment of air PM₁₀ at lag 1 day causing a 1.6%increase in the risk of KD（OR=1.016,95%CI:1.001-1.031）,which was more significant in the warm season（OR=1.023,95%CI:1.001-1.045）,male（OR=1.022,95%CI:1.003-1.041）and children under 5 years old（OR=1.016,95%CI:1.000-1.031）.PM_2.5 was associated with the risk of KD in males only at lag 1 day（OR=1.074,95%CI:1.003-1.149）.In addition,SO₂ exposure during the warm season was significantly associated with the risk of KD in children（OR=1.144,95%CI:1.004-1.304）,and the OR values for the risk of KD in females and children aged 5 and above were 1.229（95%CI:1.009-1.496）and 1.696（95%CI:1.051-2.736）,respectively.（3）In meteorological factors,temperature exposure was associated with the risk of KD at lag 0-1 day,with the maximum effect occurring on the day of onset.When the temperature rises by 1℃,the risk of KD increased by 6.0%（OR=1.060,95%CI:1.021-1.101）.And the effect was more significant in males（OR=1.061,95%CI:1.013-1.111）and patients under 5 years of age（OR=1.063,95%CI:1.021-1.106）.（4）The OR for CAL formation in children with KD was 1.267（95%CI:1.060-1.514）for every 10mg/m³ increase in air SO₂ concentration;and the risk of CAL formation gradually increased with increasing SO₂ concentration(P_overall=0.027,P_nonlinear=0.329).In addition,SO₂ was the environmental factor with the greatest influence on CAL occurrence among the six air pollutants and two meteorological factors included in this study（PIP=0.649）.（5）After adjusting for relevant covariates,the HR for regression of CAL in KD children was 0.387（95%CI:0.174-0.861）for each 1 mg/m³ increase in air CO concentration,and the likelihood of CAL regression gradually decreased with increasing air CO concentration(P_overall=0.030,P_nonlinear=0.182).Conclusions:（1）KD is more common in children under 5 years old,more males than females,with summer and winter being the seasons of high incidence.In recent years,the number of KD patients has increased year by year,and the incidence of CAL remains high.（2）Particulate matter exposure among air pollutants can increase the risk of KD in children,and sex,age,and season may modify the effects of particulate matter on KD.In addition,SO₂ exposure during the warm season had a stronger response to KD,and females and children aged 5 years and older were more sensitive to SO₂.Temperature exposure in meteorological factors can significantly increase the risk of KD,with males and children under 5 years of age being the susceptible group.（3）Air SO₂ exposure can lead to an increased risk of CAL occurrence in children with KD and there was a dose-response relationship.SO₂ was the environmental factor with the greatest effect on CAL occurrence in this study.（4）Air CO was an independent risk factor impeding CAL regression in children with KD,and there was a dose-response relationship between air CO concentration and CAL regression.