Having asthma as a child is known to impact bone health, but it only leads to an increased risk of fracture if you’re a boy, a study shows.
And it’s the disease, not the treating medications, that is the likely cause, the Australian study authors say.
Researchers from Victoria linked two datasets to create the largest study of child asthma and fractures yet conducted.
Data from more than 90 primary schools, including more than 16,000 children, were linked to a fracture registry.
Just over 800 children sustained a fracture. Boys with a recent wheeze were more likely to fracture at least one bone than children who had no recent asthma symptoms. This association was not observed in girls.
The inflammation involved in asthma was thought to negatively influence the bone development of children by interfering with mechanisms in bone formation and resorption processes, the authors said.
As to why there is an association between fractures and asthma in boys, but not girls; the authors speculate that sex differences in bone maturation and risk-taking behaviours might be driving these results.
“Girls are entering puberty at an earlier age,” Dr Sharon Brennan-Olsen, the principle author and a scientist at the University of Melbourne, said. “Therefore, their bone is also more likely to be in a different phase of development.”
Girls have the greatest bone mass accrual aged 11 to 15 years, while for boys this occurs between 14 and 15 years of age.
This study results reinforced the importance of preserving bone health in children with asthma, Dr Brennan-Olsen said.
“There are easy non-pharmacological [treatments] that GPs can be recommending to parents and children, [including] appropriate calcium intake, three to five serves every day, plus vitamin D exposure … and also physical activity. General practice has a clear role in the development of good bone during early life.”
The contribution of inhaled corticosteroids to increased fracture risk in children with asthma is controversial. But the study showed that asthma medications did not influence the association between asthma and fracture.
“We are suggesting that it is actually the underlying disease processes of the asthma influencing an increased fracture rate,” Dr Brennan-Olsen said.
“So children should always be taking their medication as prescribed by the GP, whether it is the preventer or reliever.
“Don’t change the medication because you are worried about fracture risk, because it doesn’t come into play.”
Jour of Paediatrics and Child Health, 4 April