Infant body mass index trajectories and asthma and lung function

Area of Science:

• Pediatric Respiratory Health
• Growth and Development Studies
• Epidemiology

Background:

• The relationship between early body mass index (BMI) changes and adolescent respiratory health, including asthma and lung function, is not fully understood.
• Limited prospective research exists on the critical window of lung growth during infancy.

Purpose of the Study:

• To examine the association between BMI trajectories in the first two years of life and the development of asthma and lung function in adolescence.
• To identify specific infant BMI patterns linked to respiratory outcomes in later life.

Main Methods:

• Utilized anthropometric data from 620 infants in the Melbourne Atopy Cohort Study, with measurements up to 18 times in the first 24 months.
• Applied group-based trajectory modeling to define BMI trajectories and analyzed associations with spirometry, fractional exhaled nitric oxide, and asthma status at ages 12-18 years using regression models.

Main Results:

• Identified five distinct BMI trajectories. Children with 'early-low and catch-up' or 'persistently high' BMI trajectories showed increased odds of asthma at age 18.
• These trajectories were also associated with reduced FEV1/FVC ratio and elevated fractional exhaled nitric oxide. A 'persistently low' BMI trajectory correlated with reduced FEV1 and FVC values.

Conclusions:

• Specific infant BMI trajectories, including early catch-up growth and persistently high BMI, are linked to asthma and obstructive lung patterns in adolescence.
• Persistently low early BMI is associated with restrictive lung function. Maintaining normal growth patterns may improve adolescent respiratory health.