Psycho-social stress and racial discrimination are risk factors for poorly controlled asthma
In young asthmatic Afro-Americans with high TNF-α levels reporting racial / ethnic discrimination, response to bronchodilator drugs (BDR) has increased, featuring an endotype resistant to traditional anti-asthmatic drugs.
In the United States of America, African Americans have one of the highest asthma prevalence and mortality rates. While there are well known risk factors for these disparities, psychosocial stress, including experiences of racial/ethnic discrimination, seems to be surfacing as an important risk factor.
Asthma is not a single disease but it is composed of distinct types with varying pathophysiology. These varying types are endotypes of asthma and are thought to reflect a particular biologic mechanism linked to specific health outcomes, such as inhaled corticosteroid response and frequent exacerbations
A frequently used outcome of asthma is the bronchodilator response (BDR); previous studies have shown that a 10% BDR is associated with poor control of asthma. Young people who experience racial/ethnic discrimination tend to have poor asthma control, so it is important to evaluate the effects of race and/or ethnicity discrimination on BDR.
In this recent study, the association between self-reported racial/ethnic discrimination and the BDR in 576 African-Americans aged 8 to 21 years and how this association varies with tumor necrosis factor alpha (TNF-α) levels of have been analyzed.
Almost half of participants (48.8%) reported racial/ethnic discrimination. The mean percentage of BDR was higher among participants who reported racial or ethnic discrimination than those who did not (10.8% vs. 8.9%, p = 0.006). It was also found that participants who reported racial/ethnic discrimination had a 1.7 higher BDR mean than those not declaring racial/ethnic discrimination.
However, this heterogeneity was attributed to TNF-α levels: among individuals with TNF-α high levels only, the average value of BDR was 2.78 times higher in those who reported racial/ethnic discrimination compared to those who did not. This association was not observed in subjects with low levels of TNF-α.
Concluding, BDR has increased in participants reporting racial/ethnic discrimination and this association was limited to young asthmatic Afro-Americans with TNF-α high levels, characterizing an endothelial resistance to traditional anti-asthmatic medications. These results support the usefulness of screening for racial/ethnic discrimination in subjects with asthma.
Source: Sonia Carlson, Luisa N. Borrell, Celeste Eng, Myngoc Nguyen, et al. Self-reported racial/ethnic discrimination and bronchodilator response in African American youth with asthma. PLoS ONE 2017; 12(6): e0179091.