Associations between asthma status and radiologically confirmed fracture in children: A data-linkage study.

AIM

World-wide, approximately 14% of children have prevalent asthma. As most bone accrual occurs in childhood, and data suggest a detrimental role in bone from asthma and/or medications, we investigated whether asthma was associated with radiologically confirmed fractures in a large cohort of children.

METHODS

Data from the Barwon Asthma Study (2005), a population-based, cross-sectional survey of all children attending 91 primary schools in the Barwon Statistical Division, were linked to the Geelong Osteoporosis Study Fracture Grid (2006-2007), a fracture register encompassing the Barwon Statistical Division (n = 16 438; 50.5% boys; aged 3.5-13.6 years). Asthma, ascertained from parent-reported symptoms using the International Study of Asthma and Allergies in Childhood questionnaire, was categorised as: (i) recent wheeze; and number of (ii) recent wheezy episodes; (iii) doctor visits for wheeze symptoms; and (iv) doctor visits for asthma check-ups. Using logistic regression analyses, stratified by sex and adjusted for age and medication use, we determined whether asthma was associated with radiologically confirmed fractures.

RESULTS

In total, 961 fractures were observed among 823 Barwon Asthma Study participants (5.9% of total sample; 61.1% boys). Recent wheeze and 1-3 recent wheezy episodes were associated with increased odds of fracture in boys (odds ratio (OR) 1.26, 95% confidence interval (CI) 1.03-1.55; OR 1.40, 95% CI 1.12-1.77, respectively), but not girls (OR 1.03, 95% CI 0.78-1.37; OR 0.67, 95% CI 0.38-1.19). Results were independent of age, and sustained after adjustment for medication.

CONCLUSIONS

Independent of age, asthma was associated with fracture for boys, but not girls. There is an imperative for strategies to promote bone health among children with asthma.