Association between environmental air pollution and rheumatoid arthritis flares

Abstract

Objectives Environmental air pollution has been linked to the pathogenesis of Rheumatoid Arthritis (RA). Nevertheless, evidence linking higher concentrations of air pollutants with the risk of RA reactivations is missing. The objective of the present study was to determine the association between RA flares and air pollution. Methods We collected longitudinal data of patients affected by RA and of the daily concentration of air pollutants in the Verona area. We designed a case-crossover study. We compared the exposure to pollutants in the 30-day and 60-day periods preceding an arthritic flare referent to the 30-day and 60-day preceding a low-disease activity visit. Results 888 patients with RA with 3,396 follow-up visits were included in the study. 13,636 daily air pollution records were retrieved. We found an exposure-response relationship between the concentration of air pollutants and the risk of having abnormal CRP levels. Patients exposed to greater concentrations of air pollutants were at higher risk of having CRP levels ≥5 mg/L. Concentrations of CO, NO, NO2, NOx, PM10, PM2.5 and O3 were higher in the 60-day period preceding a flare. Conclusions We found a striking association between air pollution and RA disease severity and reactivations in a cohort of patients followed over a 5-year period. The exposure to high levels of air pollutants was associated with increased CRP levels and a higher risk of experiencing a flare of arthritis. This excessive risk was evident at very low levels of exposure.

Potential Short-Term Air Pollution Effects on Rheumatoid Arthritis Activity in Metropolitan Areas in the North of Italy: A Cross-Sectional Study

“…This latter study, as well as our results, provided very small variations in the outcome measures (i.e., disease activity), which, even if statistically significant, did not reach the minimal clinically important difference [22]. Finally, due to the differences in study design (crosssectional vs. longitudinal case-crossover study) and in the period of air pollution exposure before the clinical assessment (seven days "short-term" vs. 30-day and 60-day mediumterm), this study is not comparable with the other recent Italian study [18].…”

“…Another one was conducted in China (Hefei region): the exposure to a high concentration of PM 2.5 and NO 2 was related to hospital readmission within one year after the last discharge in RA patients [17]. Recently, a longitudinal study in the Veneto region (Italy) reported a significant association between disease reactivation and medium-term air pollution exposure (30-days and 60-days before the assessment) [18].…”

Management of Rheumatoid Arthritis: An Overview

“…One of the latest research studies that has been published is a case-crossover study (which assessed a potential association between air pollutants in the Verona area and RA evolution) in 888 RA patients, showed that air pollution is linked to high C-reactive protein levels (CRP), to the severity of RA illness and its reactivations due to a poor response to biological therapies [ 74 ].…”

Environmental Air Pollution Is a Predictor of Poor Response to Biological Drugs in Chronic Inflammatory Arthritides

“…This is particularly true regarding the pathogenesis of rheumatoid arthritis (RA) (4). In addition, our group has recently demonstrated that exposure to air pollution, even at low exposure thresholds, is strictly associated with RA reactivations (5). Carbon fossil combustion contains a mixture of carbon monoxide (CO), nitric oxide (NO), nitric dioxide (NO 2 ), oxides of nitrogen (NO x ), particulate matter with a diameter of 10 μm or 2.5 μm (PM10 and PM2.5, respectively) or less, and ozone (O 3 ).…”