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Asthma and obesity
have a considerable
impact on public
health and their
prevalence has
increased in recent
years. Numerous
studies have linked
these disorders.
Most prospective
studies show that
obesity is a risk
factor for asthma
and have found a
positive correlation
between baseline
body mass index and
the subsequent
development of
asthma. Furthermore,
several studies
suggest that whereas
weight
gain increases the
risk of asthma,
weight loss improves
the course of the
illness.
Different factors
could explain this
association. Obesity
is capable of
reducing pulmonary
compliance, lung
volumes, and the
diameter of
peripheral
respiratory airways
as well as affecting
the volume of blood
in the lungs and the
ventilation-perfusion
relationship.
Furthermore, the
increase in the
normal functioning
of adipose tissue in
obese subjects leads
to a systemic
proinflammatory
state, which
produces a rise in
the serum
concentrations of
several cytokines,
the soluble
fractions of their
receptors, and
chemokines. Many of
these mediators are
synthesized and
secreted by cells
from adipose tissue
and receive the
generic name of
adipokines,
including IL-6,
IL-10, eotaxin,
tumor necrosis
factor-α,
transforming growth
factors-ß1,
C-reactive protein,
leptin, and
adiponectin.
Finally, specific
regions of the human
genome related to
both asthma and
obesity have been
identified.
Most studies point
out that obesity is
capable of
increasing the
prevalence and
incidence of asthma,
although this effect
appears to be
modest. The
treatment of obese
asthmatics must
include a weight
control program.
Key words:
Asthma. Obesity.
Overweight.
Adipocyte. Body mass
index.
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