Featured Research

from universities, journals, and other organizations

Heavy Breathing: An Obscure Link In Asthma And Obesity

Date:
August 31, 2008
Source:
American Thoracic Society
Summary:
There is a strong link between obesity and asthma and as the prevalence of both conditions has been increasing steadily, epidemiologists have speculated that there is an underlying condition that connects the two. But one long-suspected link, the systemic inflammation associated with obesity, has been essentially ruled out by a recent study that found no evidence of its involvement.

There is a strong link between obesity and asthma and as the prevalence of both conditions has been increasing steadily, epidemiologists have speculated that there is an underlying condition that connects the two.

Related Articles


But one long-suspected link, the systemic inflammation associated with obesity, has been essentially ruled out by a recent New Zealand study that found no evidence of its involvement.

"We were disappointed not to find a 'smoking gun' that would explain the common association between obesity and asthma," said lead researcher, D. Robin Taylor, M.D., of the University of Otago in New Zealand. "However, this research points us to other possibilities that future research should examine."

"We hypothesized that the low-grade systemic inflammation present in obesity would augment the inflammation of asthma (a synergistic effect)," wrote Dr. Taylor. "Or alternatively, that the inflammation of obesity might affect the airways independently (an additive effect), perhaps resulting in mixed airway inflammation."

In order to determine if there was indeed an interaction between systemic and local inflammation, the researchers recruited 79 women—20 who were obese with asthma, 19 who were of a normal weight with asthma, 20 who were obese but who did not have asthma and 20 controls.

Asthmatics were told to stop using their anti-inflammatory inhaler treatment to avoid confounding effects until "loss of control." After the withdrawal period of four weeks, subjects underwent blood tests and tests for biomarkers of systemic and airway inflammation, such as C-reactive protein (CRP) and cytokines in blood and inflammatory cells and cytokines in sputum. Those that are known to be relevant in both obesity and asthma were chosen. The researchers then analyzed for interactions between systemic and airway-specific markers of inflammation.

"What we found was that although inflammatory cells and other biomarkers of inflammation were increased, there was no significant interaction demonstrated between obesity and asthma," said Dr. Taylor.

Although their inflammation hypothesis was not supported by their results, Dr. Taylor points out that it does provide valuable direction for future research. "This does not change the fact that there is a well-established link between asthma and obesity. Sometimes a negative result is important, and the results add to our body of knowledge regarding the obesity-asthma link. Now we need to look in other directions for the answers."

Animal studies suggest that changes in innate immunity may occur with obesity. "We did not look at this in our patients. Given that asthma is immunologically driven, this is a potential avenue for further research," said Dr. Taylor. "Alternatively, it may be that dynamic changes in lung function that occur with episodes of asthma are different with excess body weight."

Whatever the link is, uncovering it will have important clinical implications. "Obese patients with asthma are more difficult to treat because their response to bronchoconstriction is exaggerated and gives the impression that the asthma is worse," said Dr. Taylor. "They may well have worse symptoms, but not as a result of underlying airway inflammation. Still, the typical response is often to increase their inhaled anti-inflammatory therapy. This is unlikely to provide the answer and may even do harm. The answer lies in dealing with the obesity itself."

The results were reported in the first issue for September of the American Journal of Respiratory and Critical Care Medicine, published by the American Thoracic Society.


Story Source:

The above story is based on materials provided by American Thoracic Society. Note: Materials may be edited for content and length.


Cite This Page:

American Thoracic Society. "Heavy Breathing: An Obscure Link In Asthma And Obesity." ScienceDaily. ScienceDaily, 31 August 2008. <www.sciencedaily.com/releases/2008/08/080829091321.htm>.
American Thoracic Society. (2008, August 31). Heavy Breathing: An Obscure Link In Asthma And Obesity. ScienceDaily. Retrieved November 26, 2014 from www.sciencedaily.com/releases/2008/08/080829091321.htm
American Thoracic Society. "Heavy Breathing: An Obscure Link In Asthma And Obesity." ScienceDaily. www.sciencedaily.com/releases/2008/08/080829091321.htm (accessed November 26, 2014).

Share This


More From ScienceDaily



More Health & Medicine News

Wednesday, November 26, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Pet Dogs to Be Used in Anti-Ageing Trial

Pet Dogs to Be Used in Anti-Ageing Trial

Reuters - Innovations Video Online (Nov. 26, 2014) Researchers in the United States are preparing to discover whether a drug commonly used in human organ transplants can extend the lifespan and health quality of pet dogs. Video provided by Reuters
Powered by NewsLook.com
From Popcorn To Vending Snacks: FDA Ups Calorie Count Rules

From Popcorn To Vending Snacks: FDA Ups Calorie Count Rules

Newsy (Nov. 25, 2014) The US FDA is announcing new calorie rules on Tuesday that will require everywhere from theaters to vending machines to include calorie counts. Video provided by Newsy
Powered by NewsLook.com
Daily Serving Of Yogurt Could Reduce Risk Of Type 2 Diabetes

Daily Serving Of Yogurt Could Reduce Risk Of Type 2 Diabetes

Newsy (Nov. 25, 2014) Need another reason to eat yogurt every day? Researchers now say it could reduce a person's risk of developing type 2 diabetes. Video provided by Newsy
Powered by NewsLook.com
Madagascar Working to Contain Plague Outbreak

Madagascar Working to Contain Plague Outbreak

AFP (Nov. 24, 2014) Madagascar said Monday it is trying to contain an outbreak of plague -- similar to the Black Death that swept Medieval Europe -- that has killed 40 people and is spreading to the capital Antananarivo. Duration: 00:42 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins