Exposure to violence associated with neutrophilic asthma in youth

Key takeaways:

• Participants aged 9 to 20 years completed an eight-item questionnaire about their exposure to violence.
• Exposure to violence increased odds for T17^HIGH asthma by 12% to 14%.

SAN DIEGO — Exposure to violence was associated with neutrophilic asthma among youth in Puerto Rico, according to a study presented at the American Thoracic Society International Conference.

“I was interested in assessing for an association between stress and T17^HIGH asthma, given that neutrophils are associated with stress, and T17^HIGH asthma is associated with neutrophils,” Kristina M. Gaietto, MD, MPH, clinical instructor of pediatrics and postdoctoral scholar, division of pulmonology, department of pediatrics, University of Pittsburgh School of Medicine and UPMC Children’s Hospital of Pittsburgh, told Healio.

“We used nasal epithelial transcriptomic profiles to define endotype rather than IgE/eosinophils/atopy, which is novel,” Gaietto said.

Gaietto called this approach particularly unique because it provided the researchers with a way to identify the T2-low endotypes involved in asthma.

The researchers measured exposure to violence (ETV) in a cohort of youth aged 9 to 20 years participating in the Epigenetic Variation and Childhood Asthma in Puerto Ricans case-control study with (n = 237) and without (n = 259) asthma via the ETV Scale validated questionnaire.

“The ETV Scale questionnaire is a validated questionnaire that assesses one’s exposure to violence over the last 12 months and over the course of one’s lifetime. It is for children and adolescents who are at least 9 years old,” Gaietto said.

Children complete the eight-item questionnaire themselves. Questions ask if they have witnessed violence, witnessed domestic violence, been the victim of violence, and heard a gunshot before.

The first four questions and questions six through eight are worth 0 to 2 points each, and the fifth question is worth 0 or 1 point. The total score is the sum of answers to all questions, ranging from 0 to 15. Zero represents low ETV and 15 represents high ETV.

Also, the researchers classified the transcriptomic profiles of participants with asthma based on their nasal expression of T2 and five T17 signature genes, including T2^HIGH/T17^LOW (T2^HIGH), T2^LOW/T17^HIGH (T17^HIGH), and T2^LOW/T17^LOW.

The participants with asthma included 69 with T2^HIGH (mean age, 15.3 years; 53.6% male), 83 with T17^HIGH (mean age, 15.5 years; 62.7% male) and 85 with T2^LOW/T17^LOW (mean age, 15.4 years; 54.1% male).

“Compared to not having asthma, exposure to violence increased odds for T17^HIGH asthma by 12% to 14%,” Gaietto said. “Hearing a gunshot increased the odds for T17^HIGH asthma by 2.4 times.”

There also was a trend toward an association between ETV and T2^HIGH asthma, but Gaietto said it was not quite statistically significant. ETV increased the odds for T2^HIGH asthma by approximately 12%, which Gaietto said resembled the effect estimate for T17^HIGH asthma.

“But hearing a gunshot increased odds of T2^HIGH asthma by 4.5 times (P = 0.005),” she continued. “I was surprised that hearing a gunshot had such a strong association with both of those asthma endotypes, particularly the T2^HIGH endotype.”

Lifetime ETV Scale scores included 4.13 ± 2.01 for T2^HIGH group, 4.28 ± 2.1 for the T17^HIGH group, 3.61 ± 2.32 for the T2^LOW/T17^LOW group and 3.61 ± 2.17 for the control group.

ETV Scale scores for exposure during the previous year included 3.01 ± 2.13 for the T2^HIGH group, 3.04 ± 2.29 for the T17^HIGH group, 2.36 ± 2.12 for the T2^LOW/T17^LOW group and 2.41 ± 2.15 for the control group.

Additionally, 94.2% of the T2^HIGH group, 90.2% of the T17^HIGH group, 77.7% of the T2^LOW/T17^LOW group and 78.7% of the controls reported hearing a gunshot at least once in their lives.

In an unadjusted analysis, participants with ETV in the previous year were 1.13 times (95% CI, 1.01-1.28) more likely to have T2^HIGH asthma.

Also, participants with lifetime ETV were 1.15 times (95% CI, 1.03-1.29) more likely to have T17^HIGH asthma, and those with ETV within the previous year were 1.14 times (95% CI, 1.02-1.27) more likely to have T17^HIGH asthma.

In an adjusted analysis, participants with lifetime ETV were 1.14 times (95% CI, 1.01-1.28) more likely to have T17^HIGH asthma, and those with ETV within the previous year were 1.12 times (95% CI, 1-1.26) more likely to have T17^HIGH asthma.

Also, the researchers said there were associations between lifetime ETV and ETV in the previous year and T2^HIGH asthma in the adjusted analysis, although they were not statistically significant. There were no associations between ETV and T2^LOW/T17^LOW in any of the analyses.

“These findings are significant because we are beginning to look at factors that are not just associated with asthma, but with specific types of asthma,” Gaietto said. “I think this is particularly important for populations such as Puerto Rican youth, who have much higher asthma prevalence than the U.S. average.”

Gaietto also said that these associations between exposure to violence and these types of asthma may be due to direct and indirect effects.

“Direct effects may include impacts on the [hypothalamic-pituitary-adrenal] axis and increased inflammatory markers, while indirect effects may include things like poor diet (stress eating), obesity (possibly due to fear of playing/exercising outside due to community violence) and depression/anxiety,” Gaietto said.

Physicians can keep these factors in mind as they assess children for asthma, she continued.

“As physicians, it’s important for us to screen for and do our best to address social determinants of health,” she said. “This just adds to the evidence that these social determinants of health are so intricately related to a patient’s health.”

The researchers plan on continuing their studies.

“We would like to test for this association between ETV and T17^HIGH asthma and between hearing a gunshot and both T2^HIGH and T17^HIGH asthma in other populations of youth,” Gaietto said.

For more information:

Kristina M. Gaietto, MD, MPH, can be reached at kristina.gaietto@chp.edu.