Elevated environmental PM2.5 increases risk of schizophrenia relapse: Mediation of inflammatory cytokines

Jiaojiao Gao; Qiannan Wei; Rubing Pan; Weizhuo Yi; Zihan Xu; Jun Duan; Chao Tang; Yangyang He; Xiangguo Liu; Shasha Song; Hong Su

doi:10.1016/j.scitotenv.2020.142008

Elevated environmental PM_2.5 increases risk of schizophrenia relapse: Mediation of inflammatory cytokines

Sci Total Environ. 2021 Jan 20:753:142008. doi: 10.1016/j.scitotenv.2020.142008. Epub 2020 Aug 27.

Authors

Jiaojiao Gao¹, Qiannan Wei¹, Rubing Pan¹, Weizhuo Yi¹, Zihan Xu¹, Jun Duan¹, Chao Tang¹, Yangyang He¹, Xiangguo Liu¹, Shasha Song¹, Hong Su²

Affiliations

¹ Department of Epidemiology and Health Statistics, School of Public Health, Anhui Medical University, Hefei, Anhui 230032, China; Anhui Province Key Laboratory of Major Autoimmune Disease, China.
² Department of Epidemiology and Health Statistics, School of Public Health, Anhui Medical University, Hefei, Anhui 230032, China; Anhui Province Key Laboratory of Major Autoimmune Disease, China. Electronic address: suhong5151@sina.com.

PMID: 32892002
DOI: 10.1016/j.scitotenv.2020.142008

Abstract

Background: Ecological epidemiology suggests that hospital admissions for schizophrenia are associated with an increased environmental PM_2.5, but no prospective study has verified this result, and the physiological mechanism is not clear.

Methods: We used a repeated-measures design to prospectively assess the association of environmental PM_2.5 and the risk of relapse in schizophrenia, and used two linear mixed-effects models to explore possible mediating effects of immune cytokines on the premise of controlling confounders.

Results: We import the data using EpiData software, and collate and analyze of the data using R software. The increase of PM_2.5 at lag0 had the greatest impact on the relapse of schizophrenia (for each 10 μg/m³ increase in PM_2.5, the relapse risk score increased by 1.504, that is to say, odds ratio (OR) = 4.500 (95% confidence interval (CI): 2.849-7.106，P < 0.001)), and cumulative effects lasted for four days with the maximum at the second day (for each 10 μg/m³ increase in PM_2.5, the relapse risk score increased by 1.301, OR = 3.673 (95%CI: 1.962-6.876，P < 0.001)). PM_2.5 exposure was statistically related to four symptom dimensions of early signs scale (ESS), and the symptoms most affected by the increased PM_2.5 were depression/withdrawal (ESSN) (OR = 1.990, 95%CI: 1.701-2.328), anxiety/agitation (ESS-A) (OR = 1.537, 95%CI: 1.340-1.763), initial psychosis (ESS-IP) (OR = 1.398, 95%CI: 1.151-1.697), and disinhibition (ESS-D) (OR = 1.235, 95%CI: 1.133-1.347). Furthermore, there are three statistically significant pathways in intermediary analysis: of PM_2.5 and relapse risk: "PM_2.5 → IL-17 → ESS", "PM_2.5 → IL-17 → ESS-A", and "PM_2.5 → IL-17 → ESS-N", and the intermediary ratio of IL-17 was 11.66%, 16.37% and 22.55%, respectively.

Conclusions: Increased environmental PM_2.5 is a risk factor for the relapse of schizophrenia. Early relapse identification and intervention based on clinical characteristics are of great significance for timely termination of relapse and slowing down of relapse.

Keywords: Mixed-effects model; PM(2.5); Relapse of schizophrenia; Repeated measures.

MeSH terms

Air Pollutants* / adverse effects
Air Pollutants* / analysis
Air Pollution* / analysis
Cytokines
Environmental Exposure
Humans
Particulate Matter / adverse effects
Particulate Matter / analysis
Recurrence
Schizophrenia* / epidemiology

Substances

Air Pollutants
Cytokines
Particulate Matter