An impact of air pollution on moderate to severe relapses among multiple sclerosis patients

Miri Elgabsi; Lena Novack; Shaked Yarza; Matan Elgabsi; Alexandra Shtein; Gal Ifergane

doi:10.1016/j.msard.2021.103043

An impact of air pollution on moderate to severe relapses among multiple sclerosis patients

Mult Scler Relat Disord. 2021 Aug:53:103043. doi: 10.1016/j.msard.2021.103043. Epub 2021 May 25.

Authors

Miri Elgabsi¹, Lena Novack², Shaked Yarza³, Matan Elgabsi⁴, Alexandra Shtein⁵, Gal Ifergane⁶

Affiliations

¹ Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel. Electronic address: miriv@post.bgu.ac.il.
² Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel; Negev Environmental Health Research Institute, Soroka University Medical Center, Beer-Sheva, Israel.
³ Negev Environmental Health Research Institute, Soroka University Medical Center, Beer-Sheva, Israel.
⁴ Jerusalem Institute of Technology.
⁵ Department of Geography and Environmental Development, Ben-Gurion University of the Negev, Beer-Sheva, Israel.
⁶ Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel; Department of Neurology, Soroka University Medical Center, Beer-Sheva, Israel.

PMID: 34126372
DOI: 10.1016/j.msard.2021.103043

Abstract

Background: Multiple Sclerosis (MS) is a chronic inflammatory disease of the central nervous system with both a genetic and environmental component.

Objective: In the current study, we examined an association between incidence of MS moderate to severe relapses and exposure to air pollutants and meteorological exposures.

Methods: We enrolled MS patients in Southern Israel during 2000-2017. Exposure assessment relied on satellite-based model of exposure to particulate matter of size <2.5 and 10 microns (PM_2.5, PM₁₀) and temperature at a spatial resolution of 1 km (Kloog et al., 2015). The information on exposure to nitrogen dioxide (NO₂), sulfur dioxide (SO₂) and ozone (O₃) levels was completed from the database of the monitoring stations. We analyzed the data using a semi-ecological approach. The monthly incidence of MS-related relapses requiring hospitalization as a function of environmental factors was analyzed by time-series technique, adjusting to sex, age and smoking. We also used a case-crossover approach to compare environmental exposure of a patient on the day of the relapse with the exposure on the relapse-free days. All estimates were adjusted to the heat index and were divided by IQR.

Results: There were 287 MS patients in the study, with an average age of 52.8 ± 16.7 years, 37% of them (107) being under 40. Mostly female (66.2%), and 13.6% of the patients smoking (47% non-smoking and 39.4% unknown). PM_2.5 was independently associated with MS relapses within the non-smoking population [Relative Risk (RR)=1.28, 95%CI:1.01-1.62]. O₃ was found adversely associated with MS relapses among patients younger than 40 [RR=1.58, 95%CI 1.03-4.43]. Based on the case-crossover approach, relapses were associated with elevated levels of PM₁₀ and NO₂ in all subjects [Odds Ratio (OR)=1.05, 95%CI:1.00-1.11; OR=1.85, 95%CI: 1.28-2.68, respectively]. An adverse association with PM_2.5 was observed in non-smokers [OR 1.12, 95%CI 1.00-1.25].

Conclusions: The findings show that MS relapses are adversely associated with an ambient exposure to PM and NO₂.

Keywords: Air pollution; Case crossover; Environment; Multiple sclerosis; PM(10).

MeSH terms

Adult
Aged
Air Pollutants* / analysis
Air Pollution* / adverse effects
Air Pollution* / analysis
Environmental Exposure / adverse effects
Environmental Exposure / analysis
Female
Humans
Male
Middle Aged
Multiple Sclerosis* / epidemiology
Particulate Matter / adverse effects
Particulate Matter / analysis
Recurrence

Substances

Air Pollutants
Particulate Matter