Increased Risk of Asthma in Children With Early Antibiotic Use
Further research is needed to clarify the effects of antibiotics on the immune system and the pathogensis of asthma.
Antibiotic use in the first 3 years of life is associated with the risk of asthma later in childhood, according to a study published in Pediatric Allergy and Immunology. The risk of asthma exacerbations in children given antibiotics in early childhood, however, was inconsistent in a meta-analysis.
Fariba Ahmadizar, PharmD, PhD, from Utrecht University in the Netherlands and colleagues studied data from 4 childhood cohorts. Two population-based cohorts examined the risk of developing asthma: Generation R, a prospective Dutch study of 7393 children from fetal life to young adulthood and SEATON, a birth cohort of 2000 children from Scotland. The outcomes of the studies were based on physician-diagnosed asthma by age 9 to 10 years in the Generation R study and at age 10 in the SEATON.
The 2 studies focused on asthma exacerbations were PACMAN, a Dutch cohort of 995 children aged 4 to 12 years on asthma medication, and BREATHE, a Scottish cohort of 1100 children aged 3 to 19 years. The outcome for asthma exacerbations was defined by asthma-associated visits to the emergency department or use of oral corticosteroids within the past 12 months for the PACMAN study and asthma-related hospitalization or oral corticosteroid use within the past 6 months in the BREATHE study.
In the pooled results of the Generation R and SEATON studies, children who received antibiotics during the first year of life were more prone to develop asthma (odds ratio [OR]: 2.18, 95% CI: 1.04-4.60) than those who were not treated with antibiotics. The Generation R study also found that children who were administered antibiotics in the first year of life had a higher rate of asthma risk (adjusted odds ratio [aOR]: 3.21, 95% CI: 1.89-5.45) than children who were first given antibiotics in their second (aOR: 2.25, 95% CI: 1.18-4.30) or third year of life (aOR: 2.21, 95% CI: 0.92-5.33).
The SEATON study did not show a significant increase in asthma occurrence for children given antibiotics in the first 6 months of life (aOR: 1.50, 95% CI: 0.91-2.46).
There were no significant associations in the asthma cohort studies, PACMAN and BREATHE, with early antibiotic use and asthma exacerbations later in life (P =.68). Both studies found that asthma exacerbations tended to occur in younger children (4 to 6 years of age in PACMAN and 3 to 6 years of age in BREATHE) compared with older children (OR: 0.93, 95% CI: 0.65-1.32).
Study limitations include a high rate of missing data (>25%) in 3 of the 4 studies, heterogeneity of the studies' designs, and the reliance on parental questionnaires to define asthma diagnosis.
“Our findings show a higher risk of asthma in children who are treated with antibiotics early in life, but no association of early life antibiotic use and asthma exacerbations later in asthmatic children,” noted the researchers. “Further research is needed to explore the effects of antibiotic on the immune system and gut microbiome in the pathogenesis of asthma.”
Ahmadizar F, Vijverberg SJH, Arets HGM, et al. Early life antibiotic use and the risk of asthma and asthma exacerbations in children. [published online April 19, 2017]. Pediatr Allergy Immunol. doi:10.1111/pai.12725