Obesity and asthma: Study finds a link in the genes

(Medical Xpress)—Genes linked to chronic inflammation in asthma may be more active in people who are obese, according to new research that uncovers several biological ties between obesity and asthma.

"Our findings point the way to the management of asthma in the obese through simple weight reduction," said first author Paresh Dandona, MD, PhD, SUNY Distinguished Professor and Chief of Endocrinology, Diabetes and Metabolism at the University at Buffalo.

The research appeared online June 26 in the journal Obesity and involved two related studies: A comparative study between obese people and people of normal weights; and an experiment that looked at how various biological indicators—including the behavior of asthma-linked genes—changed when morbidly received gastric bypass surgery.

In the comparative study, the scientists found that four genes associated with in asthma were more active in obese and , by more than 100 percent in some cases. The highest activity was found in the morbidly obese.

This increased matters because it can cause called to produce far greater amounts of inflammatory factors like interleukin 4, LIGHT and lymphotoxin? receptor which contribute to and other abnormalities in the bronchial passages in asthma.

The scientists also found higher concentrations of two asthma-related compounds in the plasma of obese and morbidly obese patients: MMP-9, which is associated with inflammation, and nitric oxide metabolites (NOM), which are an indicator of oxidative stress.

Following gastric bypass surgery in morbidly obese , MMP-9 and NOM levels dropped, along with the expression of six asthma-related genes including the key factors, , LIGHT, lymphotoxin? and interleukin 33 in parallel with weight loss and improvements in the status of their diabetes.

"Ours is the first study to provide a mechanistic link between obesity and asthma through biological/immunological mechanisms," Dandona said. "There has been, until now, no biological, mechanistic explanation other than the fact that obesity may raise the diaphragm and thus reduce lung volumes."

Importantly, the research established a connection between Type 2 diabetes, obesity and asthma based on biological mechanisms. This is important because obesity and Type 2 diabetes are associated with a more than 100 percent increase in the prevalence of asthma, Dandona said.

The comparative study included:

  • 22 patients of normal weights
  • 23 obese patients (11 with Type 2 diabetes, and the rest without)
  • and 15 morbidly obese patients with Type 2 diabetes.

The research team reported that obesity was associated with higher expression of asthma-linked genes and MMP-9 and NOM levels—whether or not patients had Type 2 diabetes.

None of the research subjects had asthma, which is one of the strengths of the study, as it provides a level of assurance that the correlations the researchers saw were not a product of the disease itself.

The next step, Dandona said, is to conduct clinical studies examining how weight loss affects asthma in patients who are obese.

"We are embarking on this project now," he said.

More information: onlinelibrary.wiley.com/doi/10… 2/oby.20524/abstract

add to favorites email to friend print save as pdf

Related Stories

Obese asthma patients have reduced treatment response

Jun 25, 2012

(HealthDay) -- Compared with lean patients, obese patients with asthma have higher neutrophil counts and a reduced response to corticosteroid treatment, according to a study published online June 12 in Allergy.

Recommended for you

Mutating Ebola viruses not as scary as evolving ones

18 minutes ago

My social media accounts today are cluttered with stories about "mutating" Ebola viruses. The usually excellent ScienceAlert, for example, rather breathlessly informs us "The Ebola virus is mutating faster in humans than in animal hosts ...

War between bacteria and phages benefits humans

1 hour ago

In the battle between our immune systems and cholera bacteria, humans may have an unknown ally in bacteria-killing viruses known as phages. In a new study, researchers from Tufts University, Massachusetts ...

Ebola kills 31 people in DR Congo: WHO

2 hours ago

An outbreak of the Ebola virus in the Democratic Republic of Congo has killed 31 people and the epidemic remains contained in a remote northwestern region, UN the World Health Organization (WHO) said Tuesday.

Dengue fever strikes models in Japan

5 hours ago

A worsening outbreak of dengue fever in Japan has claimed its first celebrities—two young models sent on assignment to the Tokyo park believed to be its source.

Japanese researchers develop 30-minute Ebola test

5 hours ago

Japanese researchers said Tuesday they had developed a new method to detect the presence of the Ebola virus in 30 minutes, with technology that could allow doctors to quickly diagnose infection.

Senegal monitors contacts of 1st Ebola patient

17 hours ago

Senegalese authorities on Monday were monitoring everyone who was in contact with a student infected with Ebola who crossed into the country, and who has lost three family members to the disease.

User comments