Navigation Links
Obesity worsens impact of asthma
Date:4/30/2008

Obesity can worsen the impact of asthma and may also mask its severity in standard tests, according to researchers in New Zealand, who studied lung function in asthmatic women with a range of body mass indexes (BMIs).

This is the first prospective study to reveal a significant comparative difference in how the airways and lungs respond to a simulated asthma attack in obese and non-obese individuals.

The research is reported in the first issue for May of the American Journal of Respiratory and Critical Care Medicine, published by the American Thoracic Society. It establishes a direct link between obesity and the development of a phenomenon known as dynamic hyperinflationwhen air breathed into the lungs cannot be exhaled. This often occurs with acute asthma, but is more frequent in obese individuals.

We have demonstrated significant differences in the changes in respiratory function that occur with asthmatic bronchoconstriction in relation to obesity, said principal investigator, D. Robin Taylor, M.D., of the University of Otago in New Zealand.

The researchers recruited 30 asthmatic women and divided them into three groups by BMI: normal weight, overweight and obese. Each woman breathed nebulized methacholine to artificially induce an asthma-like attack, and was then assessed for changes in lung function on several measures, including how much air remained in her lungs after exhalation (functional residual capacity, or FRC) and how much air she could breathe in on her next breath (inspiratory capacity, or IC).

After the methacholine challenge, the amount of bronchoconstriction was identical for each of the three groups, but the changes in FRC and IC were greatest in the obese group. This indicated to us that greater dynamic hyperinflation was occurring among obese individuals, said Dr. Taylor.

With increasing BMI, FRC was higher, whereas IC was significantly decreased. This means that among women with greater BMI, an asthma-like episode has the potential to cause greater breathing difficulties than in non-obese women, said Dr. Taylor. The greater dynamic hyperinflation means that obese individuals lose the ability to inhale as deeply or exhale as fully as normal weight individuals.

Curiously, the group of obese individuals with asthma differed from their non-asthmatic counterparts in having a lower FRC before the methacholine challenge than the non-obese group, yet still recorded a greater increase in FRC after the methacholine challenge. This is the surprising finding in our study. It is quite counterintuitive. You would expect individuals with a heavier chest wall not to develop hyperinflation quite so readily as those who are lighter. But that is not what happened, said Dr. Taylor.

Perhaps most importantly, these findings point to fundamental differences in the way that obese individuals might experience shortness of breath if they have asthma. We know that asthma in obese subjects is more likely to persist and is more likely to be perceived to be severe. These individuals often require more treatment to achieve asthma control. Our study provides an insight into why this might be happeningthe same asthma trigger produces a greater effect in obese individuals.

The study also showed that simple spirometry was inadequate to determine the level of pulmonary dysfunction which was occurring in obese individuals.

Our findings need to be explored further. We need to confirm that the differences in dynamic hyperinflation between obese and non-obese asthmatics are sufficient to explain the differences in symptoms between the two groups. Our study was not large enough to do this, said Dr. Taylor.


'/>"/>

Contact: Keely Savoie
ksavoie@thoracic.org
212-315-8620
American Thoracic Society
Source:Eurekalert

Related medicine news :

1. Virus Could Help Drive Obesity
2. Surgery for severe obesity saves lives
3. Obesity Doesnt Always Equal Diabetes
4. Obesity Rate in U.S. Still Climbing
5. Treating diabetes during pregnancy can break link to childhood obesity
6. ZIP codes and property values predict obesity rates
7. High and mighty: first common height gene identified by researchers behind obesity gene finding
8. Research Links TV/Video Game Playing With Child Obesity; Health Experts Back a New Approach
9. UT Southwesterns obesity research receives $22 million NIH Roadmap grant
10. Genaera Announces Formation of Scientific Advisory Board for Obesity Drug Candidate Trodusquemine (MSI-1436)
11. Cities Say Restaurant Nutrition Information Crucial in Fighting Obesity
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:5/26/2016)... ... 2016 , ... MadgeTech will be showcasing its line of data logging ... at the MadgeTech headquarters. With products sold in more than 100 countries around the ... NASA. , In 2012, NASA strategically set up 17 RHTemp101A MadgeTech data ...
(Date:5/26/2016)... ... May 26, 2016 , ... Memorial Day Weekend marks the unofficial ... is sharing tips to make sure your family and vehicle are ready to ... Council, there may be 439 deaths and an additional 50,500 serious injuries from motor ...
(Date:5/26/2016)... CA (PRWEB) , ... May 26, 2016 , ... ... be offering campers a multitude of activities from daily practices, arts & crafts, ... , Camp Directors Amber East-D’Anna and Christy Evans have combined backgrounds in kids’ ...
(Date:5/26/2016)... ... May 26, 2016 , ... Bunion Bootie , the manufacturer ... treatment was more than humbled by customer demand over the Mother’s Day Weekend promotion. ... sale. Now that Bunion Bootie has completely replenished its inventory levels, it hopes to ...
(Date:5/26/2016)... Petaluma, Ca (PRWEB) , ... May 26, 2016 ... ... joined the organization to provide strategic sales leadership and to further develop their ... holds a B.S. in Business Administration with a concentration in Marketing and an ...
Breaking Medicine News(10 mins):
(Date:5/26/2016)... 2016 A key trend that ... emergence of new treatments. Cardax, a development stage life ... The therapy is expected to fulfil large unmet medical ... conducting studies to develop new treatments for osteoarthritis. One ... involved in osteoarthritis are being investigated, and early trials ...
(Date:5/26/2016)... Since its commercial introduction in ... life science tool for conducting genetic studies in a ... in its new report that the industry sits on ... by a range of new applications in the clinical ... http://photos.prnewswire.com/prnh/20140723/694805 ) , Since the Human ...
(Date:5/25/2016)... HILDEN , Deutschland und GERMANTOWN, ... Zusammenarbeit mit Therawis bedient ... Entscheidungen bei Brustkrebs   QIAGEN N.V. ... QIA) gab heute bekannt, eine Lizenz- und Entwicklungsvereinbarung ... prädiktiver Assays für die Onkologie eingegangen zu sein. ...
Breaking Medicine Technology: