P0291 - Particulate Matter Under 2.5 Micrometers as a Possible Risk Factor for Eosinophilic Esophagitis

Sunday, October 24, 2021

3:30 PM – 7:00 PM PT

Location: Shoreline Exhibit Hall

Has Audio

Presenting Author(s)

Cary Cotton, MD, MPH

University of North Carolina School of Medicine
Chapel Hill, NC, United States

Cary Cotton, MD, MPH¹, Kristen Rappazzo, PhD², Charles Gaber, MSPH³, Kate Hoffman, PhD⁴, Kevin O. Turner, DO⁵, Robert Genta, DO⁵, Elizabeth Jensen, PhD, MPH⁶, Evan S. Dellon, MD, MPH, FACG¹
¹University of North Carolina School of Medicine, Chapel Hill, NC; ²United States Environmental Protection Agency, Chapel Hill, NC; ³University of North Carolina Gillings School of Global Public Health, Chapel Hill, NC; ⁴Duke University School of Medicine, Durham, NC; ⁵Inform Diagnostics, Irving, TX; ⁶Wake Forest University School of Medicine, Winston-Salem, NC

Introduction: Particulate matter smaller than 2.5 micrometers (PM2.5) is known to cause heart and lung diseases including asthma. Poor environmental quality and rural locations have been shown to be associated with eosinophilic esophagitis (EoE), but the reasons why are unknown, as is the relationship between PM2.5 and EoE. We aimed to estimate the effect of PM2.5 concentration on EoE.

Methods: We performed a case control study in a large pathology database of esophageal biopsies from across the United States. Cases were defined as ≥15 eosinophils per high-powered field in the absence of other histopathologic causes; controls were all other patients with esophageal biopsies. All patient data was geocoded by home address to the census tract of residence. Exposure to PM2.5 was determined by census tract location using estimates from the EPA’s Fused Air Quality Surface Using Downscaling model, averaged over the last five single-year concentrations prior to case occurrence. To estimate the effect of long-term PM2.5 concentration on the prevalence of EoE, we performed logistic regression adjusting for age, census tract population per square mile, census tract race/ethnicity, and census tract age distribution, using an auto-regressive correlation structure for clustering by census tract. We estimated the case control odds ratio with 95% confidence interval (CI).

Results: There were 29,956 included EoE cases and 587,381 non-EoE controls. EoE was more common in census tracts with a higher proportion of non-Hispanic White residents and in census tracts with a younger age distribution (Table). EoE was more common in rural populations where PM2.5 concentration was often lower (Figure). The case control odds ratio of EoE for each 10 additional micrograms of PM2.5 per meter cubed was 0.84 (95% CI: 0.78 – 0.90) and the matched, adjusted prevalence ratio was 0.63 (95% CI: 0.60 – 0.68).

Discussion: In this case control study, there is an inverse association between higher PM2.5 and EoE, making PM2.5 an unlikely contributor to EoE diagnosis. These results are also consistent with the previously described association between EoE and rural areas with low population density, where PM2.5 is generally lower. Further studies should be undertaken to determine different environmental risk factors for EoE.

Figure: Choropleth Map Overlaying the Unadjusted Proportion of Upper Endoscopy Biopsies with Eosinophilic Esophagitis by Census Tract with the Micrograms of Particulate Matter Under 2.5 Micrometers per Meter Cubed.

	Controls undergoing upper endoscopy with biopsies	Eosinophilic esophagitis cases
N	587,381	29,956
Age – Mean (SD)	56.3 (16.1)	45.0 (16.3)
Census tract:
Population per square mile – Mean (SD)	6,622.9 (19,001.3)	4,817.2 (13,854.9)
Percent Non-Hispanic White – Mean (SD)	73.0 (20.5)	74.9 (18.1)
Percent Black – Mean (SD)	8.9 (15.1)	7.4 (12.5)
Percent Asian – Mean (SD)	4.3 (7.0)	4.1 (6.0)
Percent Hispanic White – Mean (SD)	14.5 (18.8)	12.0 (15.2)
Percent 0 to 4 years old – Mean (SD)	5.7 (2.0)	5.8 (1.8)
Percent 5 to 9 years old – Mean (SD)	6.0 (1.8)	6.1 (1.8)
Percent 10 to 14 years old – Mean (SD)	6.2 (1.9)	6.4 (1.9)
Percent 15 to 19 years old – Mean (SD)	6.3 (2.2)	6.3 (2.3)
Percent 20 to 24 years old – Mean (SD)	5.7 (2.0)	5.7 (5.0)
Percent 25 to 34 years old – Mean (SD)	11.5 (4.8)	11.6 (5.2)
Percent 35 to 44 years old – Mean (SD)	12.3 (2.8)	12.6 (2.7)
Percent 45 to 54 years old – Mean (SD)	14.2 (3.3)	14.4 (3.3)
Percent 55 to 64 years old – Mean (SD)	12.1 (3.5)	11.8 (3.5)
Percent 65 to 74 years old – Mean (SD)	7.8 (4.7)	7.1 (3.8)
Percent 75 to 84 years old – Mean (SD)	4.9 (4.0)	4.2 (3.2)
Percent 85 to 99 years old – Mean (SD)	2.0 (2.1)	1.8 (1.8)
N, number, SD, standard deviation.

Table: Individual and Census Tract Characteristics of Included Cases and Controls

Disclosures:

Cary Cotton indicated no relevant financial relationships.

Kristen Rappazzo indicated no relevant financial relationships.

Charles Gaber indicated no relevant financial relationships.

Kate Hoffman indicated no relevant financial relationships.

Kevin Turner indicated no relevant financial relationships.

Robert Genta indicated no relevant financial relationships.

Elizabeth Jensen indicated no relevant financial relationships.

Evan Dellon indicated no relevant financial relationships.

Cary Cotton, MD, MPH¹, Kristen Rappazzo, PhD², Charles Gaber, MSPH³, Kate Hoffman, PhD⁴, Kevin O. Turner, DO⁵, Robert Genta, DO⁵, Elizabeth Jensen, PhD, MPH⁶, Evan S. Dellon, MD, MPH, FACG¹. P0291 - Particulate Matter Under 2.5 Micrometers as a Possible Risk Factor for Eosinophilic Esophagitis, ACG 2021 Annual Scientific Meeting Abstracts. Las Vegas, Nevada: American College of Gastroenterology.