Low levels of vitamin D are associated with lower lung function and greater medication use in children with asthma

Low Vitamin D Levels Associated With More Asthma Symptoms and Medication Use

ScienceDaily (Apr. 20, 2010) — Low levels of vitamin D are associated with lower lung function and greater medication use in children with asthma, according to researchers at National Jewish Health. In a paper published online this week in the Journal of Allergy & Clinical Immunology, Daniel Searing, MD, and his colleagues also reported that vitamin D enhances the activity of corticosteroids, the most effective controller medication for asthma.

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"Asthmatic children in our study who had low levels of vitamin D were more allergic, had poorer lung function and used more medications," said Dr. Searing. "Conversely, our findings suggest that vitamin D supplementation may help reverse steroid resistance in asthmatic children and reduce the effective dose of steroids needed for our patients."

The researchers examined electronic medical records of 100 pediatric asthma patients referred to National Jewish Health. Overall, 47 percent of them had vitamin D levels considered insufficient, below 30 nanograms per milliliter of blood (ng/mL). Seventeen percent of the patients had levels below 20 ng/mL, which is considered deficient. These levels were similar to vitamin D levels found in the general population.

Patients low in vitamin D generally had higher levels of IgE, a marker of allergy, and responded positively to more allergens in a skin prick test. Allergies to the specific indoor allergens, dog and house dust mite, were higher in patients with low vitamin D levels. Low vitamin D also correlated with low FEV1, the amount of air a person can exhale in one second, and lower FEV1/FVC, another measure of lung function. Use of inhaled steroids, oral steroids and long-acting beta agonists were all higher in patients low in vitamin D.

"Our findings suggest two possible explanations," said senior author Donald Leung, MD, PhD. "It could be that lower vitamin D levels contribute to increasing asthma severity, which requires more corticosteroid therapy. Or, it may be that vitamin D directly affects steroid activity, and that low levels of vitamin D make the steroids less effective, thus requiring more medication for the same effect."

The researchers performed a series of laboratory experiments that indicated vitamin D enhances the action of corticosteroids. They cultured some immune cells with the corticosteroid dexamethasone alone and others with vitamin D first, then dexamethasone. The vitamin D significantly increased the effectiveness of dexamethasone. In one experiment vitamin D and dexamethasone together were more effective than 10 times as much dexamethasone alone.

The researchers also incubated immune-system cells for 72 hours with a staphylococcal toxin to induce corticosteroid resistance. Vitamin D restored the activity of dexamethasone. "Our work suggests that vitamin D enhances the anti-inflammatory function of corticosteroids,' said Dr. Leung. "If future studies confirm these findings vitamin D may help asthma patients achieve better control of their respiratory symptoms with less medication."

This study comes on the heels of another paper by National Jewish Health faculty, which showed that low levels of vitamin D in adult asthma patients are associated with lower lung function and reduced responsiveness to corticosteroids.

New Research Suggests that Bacteria May Cause Asthma Attacks in Children

Bacteria to Blame in Asthma Attacks in Children, Research Suggests

ScienceDaily (Oct. 7, 2010) — Doctors have long known that viral infections can bring about asthma attacks and the shortness of breath, coughing, and wheezing associated with them. But while viral infections cannot be treated, scientists at the Danish Paediatric Asthma Centre (DPAC) at the University of Copenhagen and Gentofte Hospital have discovered that treatable bacterial infections can also cause asthma attacks. The discovery could revolutionize treatment.

"We found a significant relationship between bacterial infections and acute asthma attacks -- above and beyond the expected relationship between viral infections and attacks," says Hans Bisgaard, a professor of pediatrics at the DPAC.

The study examined 361 children between the ages of four weeks and three years to determine the presence of viral and bacterial infections during severe asthma attacks. The results conclude that the number of attacks was just as high in children with bacterial respiratory infections as in those with viral infections.

Using antibiotics to treat asthma attacks?

"This indicates that bacteria can exacerbate asthma symptoms even if they aren't infected with a virus," Professor Bisgaard says. "The findings open up an entirely new method for treating severe asthma attacks. We can't treat viral infections, but scientists will now look into whether treatment with antibiotics can help children when they have an asthma attack if they are also suffering from a bacterial infection."
"Being able to use antibiotics to treat asthma attacks in children would be revolutionary," Professor Bisgaard says.

The effects of antibiotics in treating asthma attacks will now be examined in large-scale, clinical study by the DPAC.
The research has been published in British Medical Journal on 4 October 20

Signs of a Pending Asthma Attack

Asthma Early Warning Signs

• A runny nose, headache, or itchy chin often precedes an asthma attack.
• Trouble sleeping and feeling tired are other typical signs.
• So are dark circles under the eyes and less tolerance for exercise.
• Frequently, people get moody before an asthma attack starts.

A Persistent Cough

Signs of an asthma attack vary from one attack to the next. One time there may be little or no coughing before an attack. The next time, there may be a persistent cough, especially at night.

The cough is typically dry and hacking. (Sometimes, however, the cough may be wet and productive.)
Avoid taking cough medicine. Cough medicine won’t help the asthma.

Chest and Neck Retractions
When it’s hard to breathe, the tissue in the chest and neck may sink in with each breath. This is called retraction.
Retractions indicate that not enough air is getting into the lungs, and are signs of a medical emergency. Call 911 or see a doctor immediately.
In children other signs of deterioration in breathing are:

• poor appetite
• fatigue
• decreased activity

Go to WebMD to learn about more signs of a pending asthma attack here: 
Signs of a Pending Asthma Attack