PM2.5 exposure and household income are associated with lung function abnormalities in children with sickle cell disease

Rationale: Cardiopulmonary dysfunction is a major contributor to mortality among persons with sickle cell disease (pwSCD). Despite this, little is known regarding environmental drivers of lung function decline.

Objective: We hypothesized that environmental and socioeconomic variables have a significant effect on lung function in pwSCD that can be detected by spirometry.

Methods: We retrospectively analyzed all spirometry results from pwSCD followed in the Pediatric Pulmonology clinic at the Children's Hospital of Philadelphia since 1 January 2016.

Results: The study included 349 spirometry tests from 128 patients, primarily "Black or African American" (88%) and male (61%). More frequent exposure to PM2.5 above 25 μg/m³ was associated with higher odds of obstruction. Specifically, when compared to incidence of exposure to PM2.5 above 25 μg/m³ <25th percentile, both pwSCD exposed to 25th-75th percentile and pwSCD >75th percentile had higher odds of obstruction on spirometry (25th-75th: odds ratio [OR]: 9.6, p = .017; >75th: OR: 31.85, p = .002) despite correction for potential confounders. Similarly, median household income below the mean was associated with higher odds of restriction (OR: 4.37; p = .009).

Conclusions: We report higher odds of obstruction in pwSCD frequently exposed to PM2.5 concentrations above 25 μg/m³ and higher odds of restriction in pwSCD with lower household income. Our findings link spirometry patterns to modifiable risk factors indicating that there may opportunities for early intervention in pwSCD that have been referred to a pulmonology clinic. Further research is needed to assess if these findings can be generalized to the wider population of pwSCD.