/publications/issue/2009/october2009/AsthmaWatch-1009

Asthma Watch

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Weight Affects Response to Asthma Meds

The theory that obesity can make asthma worse may not be the case. The condition, however, could dull the response to medications commonly used to manage asthma, according to a study reported in the June 2009 issue of the Journal of Allergy and Clinical Immunology.

“There has been a suggestion that obesity and asthma may be related, particularly with regard to obesity increasing one’s risk of developing asthma or making asthma more severe or difficult to treat,” said lead author E. Rand Sutherland, MD.

For the study, the researchers looked at the body mass index and treatment data on 1256 patients with mild-to-moderate asthma. The results indicated that overweight and obese patients fared somewhat worse on standard measures of asthma severity. The outcome was not enough to result in any real clinical difference, noted the investigators.

The response to medications, however, produced different results. An analysis of a subgroup of 183 patients found that thinner individuals using inhaled corticosteroids showed a 55% lower level of one measure of airway inflammation.

Breakthrough in Severe Asthma Found

Researchers from King’s College London and Imperial College London believe they have discovered a crucial element in the development of chronic asthma. The study, recently reported in the Proceedings of the National Academy of Sciences, discussed why the structure and function of asthma patients’ airways are changed or remodeled and how this contributes to chronic asthma.

The investigators explained that remodeling happens when the tiny airways in the lungs change gradually with time as the lungs respond to certain particles, such as dust or mold in the air people breathe. Airway remodeling is found in the lungs of young people and makes the chronic condition almost impossible to control. A key element of airway remodeling is changes to the muscles which line the airways. For patients with asthma, these cells tend to multiply and become bigger, increasing their ability to squeeze the airways and cause breathing trouble. Reversing airway remodeling cannot be done once the process has occurred.

“This research into the causes of asthma provides us with vital clues as to how such symptoms could be stopped, and it has uncovered important information, which we hope will lead to the creation of effective new treatments for the millions of people in the [United Kingdom] affected by asthma symptoms,” said Elaine Vickers, PhD, research relations manager at Asthma UK.

Breathe Better with Yoga

Doing yoga a few times A week can improve symptoms and quality of life for individuals with asthma. Some patients have been able to cut back on some of their asthma medication.

For the study, 20 participants aged 20 to 65 were randomly assigned to practice Hatha yoga 2½ hours a week or a nonyoga group for 10 weeks. The researchers based the findings on a questionnaire that measured frequency and severity of symptoms, activities associated with breathlessness, and social and psychological functioning.

In addition, heart rate variability, oxygen consumption, and ventilation were assessed while the participants performed 2 tasks each: handgrip for 3 minutes and an upright tilt for 5 minutes.

The findings, presented recently at the American College of Sports Medicine’s annual meeting, showed that overall scores of the yoga group improved an average of almost 43%. The data showed few or no differences between the groups in heart rate variability, oxygen consumption, or ventilation.

Hospital Stays Greater with Flu Shots

Children with asthma who get an annual flu shot face greater odds of hospitalization, compared with children who are not inoculated. The researchers noted that the results most likely have to do with the severity of asthma in children getting the vaccine rather than with any deficiency in the vaccine.

The study involved 263 children who had visited the Mayo Clinic between 1999 and 2006 with laboratory-confirmed influenza. The children—including those with asthma—who received the annual flu vaccine were nearly 3 times more prone to be hospitalized. Study author Avni Y. Joshi, MD, said there is no indication that the vaccine was responsible for the hospitalization. It may just mean that the shot is not effective in preventing hospital stays.

“The flu shot may be safer in terms of triggering a wheezing episode, but we don’t know how effective it is. We need more studies to assess the effectiveness of different kinds of vaccines,” she explained.

FAST FACT: About 70% of people with asthma also have allergies.