Pediatric patients prescribed antibiotics in their first year of life were more likely to develop asthma later in childhood, including in sibling comparisons, according to a recent study.
In a nationwide registry study, published in BMJ Medicine, investigators analyzed the association between systemic antibiotic use in the first year of life and the subsequent development of immune mediated diseases and overweight in childhood and adolescence. Led by Sarah Brandt, of the Copenhagen Prospective Studies on Asthma in Childhood at the Herlev and Gentofte Hospital in Gentofte, Denmark, and colleagues used linked data from several Danish national registries, including the Danish Civil Registration System, Danish National Prescription Registry, and Danish National Patient Registry to build a cohort of 518,483 pediatric patients born between 1998 and 2006. A sibling-matched design was also applied to address potential unmeasured familial confounding.
The participants were followed for a mean of 13.2 years. Among the total population, 40.3% (n = 209,013) of them received systemic antibiotics prior to age 1. The investigators assessed the incidence of asthma, allergy, eczema, celiac disease, juvenile arthritis, type 1 diabetes, and overweight using Cox proportional hazards regression, adjusting for key demographic and clinical covariates—including maternal smoking during pregnancy, birth characteristics, and socioeconomic status.
Antibiotic exposure during infancy was associated with an increased risk of several immune-mediated conditions. Hazard ratios (HR) ranged from 1.18 to 1.57, with the strongest associations observed for asthma and eczema. A dose-response relationship was evident; each additional antibiotic course was associated with a 7% to 18% increase in risk for most outcomes, excluding celiac disease and type 1 diabetes.
In the sibling-matched analysis of 272,753 pediatric patients from 126,632 sibships, most associations were attenuated or no longer statistically significant. However, asthma and eczema remained consistently associated with early antibiotic exposure, with HRs ranging from 1.07 to 1.35. No consistent associations were observed for the timing or type of antibiotic, with ampicillin (53%), penicillin (36%), and macrolides (8%) being the most frequently prescribed.
The findings suggested that early-life antibiotic use may be associated with an increased risk of asthma and eczema independent of familial factors, while associations with other immune-mediated diseases and overweight were attenuated in sibling comparisons. The investigators noted that these results supported further studies exploring familial susceptibility and the potential implications for antibiotic prescribing practices.
The study authors reported no conflicts of interest related to this study.