Men at higher risk for asthma
Men who are obese are more likely to have
asthma, with the heaviest men having almost a four times higher
risk of developing asthma than the thinnest men, according to
study results presented at the annual meeting of the American
Academy of Allergy, Asthma and Immunology.
there's been interest in the possibility that increasing obesity
is part of what's going on with the increase in asthma," explained
Kathryn Held, a doctoral candidate in medical anthropology at
the University of Oklahoma in Norman. The prevalence of asthma
in men increased nearly 42% between 1982 and 1994, according
to the Academy.
The reasons for these findings are unknown. "Physicians have
observed for a long time that asthmatics tended to be heavier,
but the assumption has been that asthmatics restricted their
activity and thus gained weight," Held said. But she noted that
studies over time in women and children suggest that the obesity
comes first, and the youngest children -- whether obese or not
-- are more likely to develop asthma if their mothers are obese.
Held's findings were based on questionnaire data from almost
12,000 men collected by the Centers for Disease Control and
Prevention for the Household Youth Data File, which links characteristics
of children with those of their parents. She divided the data
into four groups according to the men's body mass index (BMI).
She found that the prevalence of asthma in each group, in percent
of men affected from thinnest to heaviest, was 5.30%, 8.09%,
8.93% and 17.31%.
When Held studied whether obese asthmatic men also had asthmatic
children, she found that the association between the men's obesity
and asthma was stronger than the association between having
asthma and having a child with asthma.
Also, countries where people are thinner have a smaller proportion
of asthmatics than North America, New Zealand, Australia and
the United Kingdom, she said. These are all places where there
is a rapid increase in the prevalence of both obesity and asthma.
evidence indicates that asthma follows the same pattern as other
'diseases of modernization' of increasing risk with increasing
overnutrition and overweight," the researchers conclude.
Nonetheless, Held admitted that none of these data prove whether
obesity causes asthma or the other way around. "That's obviously
the next step (in research), the causal relationship," she said.
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