Rationale: Better characterization of childhood wheeze phenotypes using newer statistical
methods provides a basis for addressing the heterogeneity of childhood asthma. Outcomes of
these phenotypes beyond childhood are unknown.
Objectives: To determine if adolescent respiratory symptoms, lung function and changes in
lung function over adolescence differ by childhood wheeze phenotypes defined through
Latent Class Analysis.
Methods: A prospective birth cohort (Melbourne Atopy Cohort Study) followed 620 high
allergy-risk children, recording respiratory symptoms and spirometry at 12 and 18 years.
Regression analyses identified relationships between wheeze phenotypes (Never/Infrequent ;
Early Transient ; Early Persistent ; Intermediate Onset ; Late Onset ) and: lung function,
change in lung function (12-18yrs), respiratory symptoms, and asthma. Baseline :
Measurements and Main Results: Deficits in expected growth of lung function, measured
by change in pre-bronchodilator Forced Expiratory Volume over 1 second (FEV1) between
12 and 18 years were found for: Early Persistent (reduced 290mls; 95 CI 82,498);
Intermediate Onset (reduced 210mls; 62,359); and Late Onset wheeze; (reduced 255mls;
69,442 ). Intermediate Onset wheezers had persistent FEV1 deficit post bronchodilator at 18
years (reduced 198mls; 46,350). Current asthma risk was increased for all phenotypes except
Early Transient, which was also not associated with lung function deficits at 12 or 18 years.
Conclusions: Persistent wheeze phenotypes in childhood were associated with reduced
growth in pre-bronchodilator FEV1 over adolescence. Intermediate Onset wheezers showed irreversible airflow limitation by 18 years. Conversely, Early Transient wheeze was a benign
condition with no sequelae for respiratory health by age 18.