Lower levels of vitamin D may cause structural changes in the airway muscles of children with STRA, making breathing more difficult. The study provides important new evidence for possible treatments for the condition.
The findings were published online ahead of the print edition of the American Thoracic Society's American Journal of Respiratory and Critical Care Medicine.
"This study clearly demonstrates that low levels of vitamin D are associated with poorer lung function, increased use of medication, worse symptoms and an increase in the mass of airway smooth muscle in children with STRA," said Atul Gupta, MRCPCH, M.D., a researcher from Royal Brompton Hospital and the National Heart and Lung Institute (NHLI) at Imperial College and King's College London. "It is therefore plausible that the link between airway smooth muscle mass and lung function in severe asthma may be partly explained by low levels of vitamin D."
While most children with asthma can be successfully treated with low doses of corticosteroids, about 5 to 10 percent of asthmatic children do not respond to standard treatment. These children have severe therapy-resistant asthma, or STRA, experience more asthma episodes and asthma-related illnesses, and require more healthcare services, than their treatment-receptive peers.
Although previous studies of children with asthma have linked increases in airway smooth muscle mass with poorer lung function and in vitro studies have established a connection between levels of vitamin D and the proliferation of airway smooth muscle, this is the first study to evaluate the relationship between vitamin D and the pathophysiology of children with STRA.
"Little is known about vitamin D status and its effect on asthma pathophysiology in these patients," Dr. Gupta noted. "For our study, we hypothesized that children with STRA would have lower levels of vitamin D than moderate asthmatics, and that lower levels of vitamin D would be associated with worse lung function and changes in the airway muscle tissue."
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.The researchers also examined tissue samples from the airways of the STRA group to evaluate structural changes in the airway's smooth muscle.
At the conclusion of the study the researchers 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 was also 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," Dr. Gupta said.
The findings suggest new treatment strategies for children suffering from difficult-to-treat asthma, he added.
"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," Dr. Gupta said.
Before any widespread treatment recommendations can be made, however, larger studies will need to be conducted to confirm the results, he added.
"The determination of the exact mechanism between low vitamin D and airway changes that occur in STRA will require intervention studies," Dr. Gupta said. "Hopefully, the results of this and future studies will help determine a new course of therapy that will be effective in treating these children."
Brian Kell | EurekAlert!
Researchers identify new way to unmask melanoma cells to the immune system
17.01.2018 | Duke University Medical Center
Study advances gene therapy for glaucoma
17.01.2018 | University of Wisconsin-Madison
What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...
For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.
Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...
At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.
No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...
Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.
Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...
The oceans are the largest global heat reservoir. As a result of man-made global warming, the temperature in the global climate system increases; around 90% of...
08.01.2018 | Event News
11.12.2017 | Event News
08.12.2017 | Event News
17.01.2018 | Ecology, The Environment and Conservation
17.01.2018 | Physics and Astronomy
17.01.2018 | Awards Funding