LONDON—Low levels of vitamin D may cause children with severe therapy-resistant asthma (STRA) to have poorer lung function and worse symptoms compared to children with moderate asthma, according to a new study published in the American Journal of Respiratory and Critical Care Medicine.
Researchers at Imperial College and King’s College London evaluated the relationship between vitamin D and the pathophysiology of children with STRA. The researchers enrolled 86 children in the study, including 36 children with STRA, 26 with moderate asthma and 24 non-asthmatic controls, and measured the relationships between vitamin D levels and lung function, medication usage and symptom exacerbations. They also examined tissue samples from the airways of the STRA group to evaluate structural changes in the airway’s smooth muscle.
They found children with STRA had significantly lower levels of vitamin D, as well as greater numbers of exacerbations, increased use of asthma medications and poorer lung function compared to children with moderate asthma and non-asthmatic children. Airway muscle tissue mass also was increased in the STRA group.
“The results of this study suggest that lower levels of vitamin D in children with STRA contribute to an increase in airway smooth muscle mass, which could make breathing more difficult and cause a worsening of asthma symptoms," the researchers said. “Our results suggest that detecting vitamin D deficiency in children with STRA, and then treating that deficiency, may help prevent or reduce the structural changes that occur in the airway smooth muscle, which in turn may help reduce asthma-related symptoms and improve overall lung function."
