Characterizing Differences in Socioeconomic and Environmental Factors Associated With Sarcoidosis Among Black and White Patients in North Carolina
Stiefer, A; Huang, Y-CT
Published in: American Journal of Respiratory and Critical Care Medicine
Rationale: Sarcoidosis is a granulomatous lung disease with diverse clinical manifestations. In the US, the prevalence of sarcoidosis has significant geographic variations with the Northeast and the South having higher rates. In the South, African Americans are at higher risk for developing sarcoidosis though Caucasians are disproportionately affected compared to other US regions. This indicates, in addition to genetic determinants, environmental factors play an important role. Certain occupational environments are associated with sarcoidosis, but the role of the residential environment is unclear. In this study, we hypothesized there were differences in residential environmental quality between African Americans and Caucasian patients with sarcoidosis. Methods: We conducted cross-sectional analysis of patients (age≥18) with sarcoidosis (ICD-10:D86.9) between January 1, 2013 and December 31, 2022 at Duke Health utilizing an institution-specific data query tool. Participants were limited to those residing in North Carolina with self-reported race of African American (“Black”) or Caucasian (“White”). Each participants’ census tract was extracted and matched with 25 measures of environmental and socioeconomic risk as indexed by the Centers for Disease Control and Prevention's Environmental Justice Index (EJI) (Table 1). Principal component analysis was used to examine how EJI measurements varied together in both the Black and White cohorts. The number of factors were determined using Kaiser's stopping rule and scree plots. For interpretation, principal components were rotated using the varimax rotation method. Individual variables with loadings > 0.6 were retained. The protocol was approved by Duke University IRB (Pro00114768). Results: In the Black cohort (n=2,344, 64.5% female), two factors were identified. Factor 1 consisted of 8 variables related to socioeconomic status (SES) with POV200 having the highest loading (0.972); Factor 2 consisted of 7 variables related to environmental characteristics (EC) with DSLPM having the highest loading (0.973). In the White cohort (n=1,413, 57.5% female), two factors were identified. Factor 1 consisted of 8 variables related to SES with POV200 having the highest loading (0.969); Factor 2 consisted of 5 variables related to EC with DSLPM having the highest loading (0.913). Notably PM (0.713) and IMPWTR (0.642) were two variables in Factor 2 in the Black cohort, but not in either Factor 1 or Factor 2 in the White cohort. Conclusions: Black and White patients with sarcoidosis in North Carolina appeared to have common social and environmental pressures. PM and IMPWTR were only seen in the Black patients, indicating they could be unique environmental factors deserving further studies.
