Investigators from multiple institutions assessed the role of air pollution on lung function in minority youth with asthma and evaluated whether the relationship is modified by global genetic ancestry. For the study, Latino and African American children and adolescents (8–21 years old) from 5 geographical regions in the mainland United States and Puerto Rico were enrolled. Participants were part of 2 parallel case-control studies (Genes–Environments and Admixture in Latin Americans [GALA II], and Study of African Americans, Asthma, Genes, and Environment [SAGE II]) designed to study gene–environment interactions in minority asthmatic children; for the current study only asthma “cases” were included. Lung function was measured in study participants using spirometry (forced expiratory volume in one second [FEV1] and forced expiratory flow between 25% and 75% of vital capacity [FEF25–75]). Pollution exposure was assessed based on each participant’s residence and regional air pollution data for NO2, sulfur dioxide, ozone, and particulate matter for aerodynamic diameter ≤2.5 mm (PM2.5) and ≤10 mm. Genetic ancestry was calculated by using single nucleotide polymorphisms to obtain estimates of proportions of African, European, and Native American ancestry for Latinos, and proportions of African and European ancestry for African American youth enrolled in the study. Regression analyses were conducted to assess the effect of specific pollutant exposure on lung function, after adjusting for potential confounders. Effect modification by African and Native American ancestry was also assessed.
A total of 1,968 participants with asthma were studied: 1,449 from the GALA II Latino American Study and 519 from the SAGE II African American Study. Participants from the GALA II study had a mean age of 12.6 years, while those from the SAGE II study had a mean age of 13.7 years. Lower FEV1 and FEF25–75 were significantly associated with average lifetime exposure to PM2.5 but not other types of pollutants studied. This effect was not significantly modified by the percentage of genetic African or Native American ancestry; overall, however, genetic African ancestry was associated with lower lung function.
The authors conclude that reduced lung function is associated with average lifetime exposure to PM2.5 in minority youth with asthma, but a modifying effect by global genetic ancestry was not observed.
Dr. Lesser has disclosed no financial relationship relevant to this commentary. This commentary does not contain a discussion of an unapproved/investigative use of a commercial product/device.
Conspicuously high rates of asthma occur among minority children. This group suffers from significantly higher morbidity and mortality from the disease compared to the general population.1,2 Air pollution has been linked to...