TOPLINE:

In a registry-based study, pulmonary exacerbations (PEx) affected nearly one third of children with cystic fibrosis in the first 3 years of life and were linked to lower lung function at age 6 and lower BMI at age 3. The risk was higher with Medicaid coverage, pancreatic insufficiency, and a diagnosis of asthma before the age of 3 but lower with exclusive breastfeeding before the age of 6 months.

METHODOLOGY:

• Researchers analyzed registry data of infants and young children with cystic fibrosis to identify risk factors in the first year of life associated with PEx between ages 1 and 3 and to examine associations between early PEx and subsequent BMI and lung function.
• They included 7342 patients diagnosed via newborn screening or at the first visit to a cystic fibrosis center by 60 days of age, with continuous follow-up for the first 6 years. Among patients with at least one PEx, 49% were girls.
• Data on pulmonary function at age 6 years were collected, and BMI z-scores were recorded at least once between ages 3 and 4.
• The primary outcome was the occurrence of at least one PEx between ages 1 and 3; secondary outcomes were BMI z-score at age 3 years and percent predicted forced expiratory volume in 1 second at age 6 years.

TAKEAWAY:

• Overall, 35% of patients experienced a PEx in the first 3 years of life; among them, 62% had at least one PEx in the first year of life.
• Medicaid coverage, pancreatic insufficiency, a diagnosis of asthma before the age of 3, use of hypertonic saline prior to age 1, and a positive respiratory culture for methicillin-resistant Staphylococcus aureus were each associated with significantly increased odds of PEx.
• Exclusive breastfeeding before the age of 6 months vs no breastfeeding was significantly associated with reduced odds of PEx.
• Children with more than one PEx before the age of 3 had a lower percent predicted forced expiratory volume in 1 second at age 6 than those without (P < .0001); a single PEx before the age of 3 was also associated with a lower BMI z-score at age 3 (P = .0418).

IN PRACTICE:

“These data will be helpful for clinicians in counselling caregivers of VY-PwCF [very young people with cystic fibrosis] on the risk factors for PEx and identifying patients at higher risk of PEx in the first 3 years of life,” the authors wrote.

SOURCE:

This study was led by Aoife Corcoran, Children’s Hospital of Philadelphia, Philadelphia. It was published online on December 8, 2025, in Pediatric Pulmonology.

LIMITATIONS:

The registry does not capture data on PEx treated with oral antibiotics or managed via phone, so the true frequency was likely underestimated. No standard definition of a PEx is available, and centers varied in how they diagnosed and treated them, complicating interpretation. The registry also lacks data on medication adherence and airway clearance, which could have influenced outcomes.

DISCLOSURES:

This study was supported by the Caruso Family Foundation. The authors reported having no conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.