There have been previous research findings that have shown asthma to be more
common in obese individuals but this new research goes further to show that
the largest portion of the association between the two disorders could be explained
by a common set of genetic factors.
Dr. Teal Hallstrand, assistant professor of pulmonary and critical care medicine
at the University of Washington in Seattle, headed the study. The researchers
analyzed both identical and fraternal twins and compared the frequency of asthma
and obesity in both. Based on the analysis of the 1001 identical and 383 fraternal
same-sex twin pairs within the University of Washington Twin Registry, researchers
found that the largest portion of the association between asthma and obesity
could be attributed to a common set of genetic factors, referred to as genetic
pleiotropy. This finding implies that the same genetic factors may have a causal
influence on both asthma and obesity.
Asthma and obesity are increasingly common disorders and both can be life-threatening
if not properly treated. While this research shows a genetic link between asthma
and obesity, a fundamental question about the relationship between obesity
and asthma remains. The fundamental question is whether the association between
asthma and obesity is predominantly genetic or predominantly based on environmental
The genetic researchers of this study also report that the effects of environmental
exposures on asthma and obesity are likely to occur primarily in the context
of a specific genetic background, referred to as gene-by-environment effects.
This indicates that the two disorders, while also partially induced by environmental
factors the effects of asthma and obesity based on environment are likely to
be brought about due to genetic makeup.