Early life wheeze clusters in the Isle of Wight birth cohort

Abstract

Infantile wheezing though usually transient may also persist. We hypothesised that cluster analysis could reveal the diversity of infantile wheeze. Participants in the Isle of Wight birth cohort (n=1456) were assessed at 1 and 2-years (infancy). Cluster analysis was performed in infantile wheezers (n=242) using 5 clinical characteristics (atopy, eczema, rhinitis, food allergy and wheezing frequency). Five clusters were found and further assessed;

High severity non-atopic smoking associated wheeze: 13.9% (n=32) High wheeze frequency, prevalence of nasal symptoms, food allergy and asthmatic family history. Low prevalence of atopy. High tobacco exposure in pregnancy and infancy.

Moderate severity atopic wheeze: 24.5% (n=56) Moderate wheeze frequency. High prevalence of nasal symptoms, atopy and asthmatic family history. Lowest tobacco exposure in pregnancy.

Low severity non-atopic wheeze: 26.2% (n=60) Lowest wheeze frequency. Low prevalence of atopy, eczema and food allergy. Highest birthweight/Body Mass Index (BMI) in infancy. Low prevalence of tobacco exposure in pregnancy/in infancy and chest infections in infancy.

Moderate severity infantile wheeze: 21.8% (n=50) Moderate wheeze frequency. Low prevalence of atopy and nasal symptoms. Highest prevalence of pet exposure and exclusive breastfeeding.

High severity male atopic wheeze: 19.2% (n=44) High wheeze frequency, prevalence of atopy, eczema and asthmatic family history. Low prevalence of nasal symptoms. Male predominant. High prevalence of tobacco exposure in infancy and of chest infections in infancy. Lowest BMI in infancy.

In conclusion distinct infantile wheeze clusters exist with varying severity and features. Severe clusters were associated with parental smoking.