Obesity May Be Linked to Adult-Onset Asthma in Women
WebMD News Archive
"In a study like the Nurses' Health Study, there are more than 900
variables," says Albert Wu, MD, MPH, in an interview seeking objective
commentary on the study. "There are many, many predictive variables and
there is the possibility of a spurious association." Wu is associate
professor of healthy policy and management and medicine at Johns Hopkins
University in Baltimore.
Before recommending weight loss as a strategy to prevent adult-onset asthma,
Wu tells WebMD that "the finding needs to be replicated in a study intended
to answer the question." In the Nurses' Health Study, Wu says, "there
are so many potential associations that there is always the risk of chance, and
that it is not a true association." Because the Nurses' Health Study has
such a "large number of candidate variables and an equally large number of
disease and other health outcomes," he says, "that a finding like this
deserves to be replicated."
Other experts also question the study's findings. The authors of an
accompanying editorial urge confirming the results in other, more diverse
populations. And they ask whether the chicken or the egg came first -- was the
asthma a reason the adult nurses were overweight, or were they overweight
Michael Schatz, MD, a spokesperson for the American Academy of Asthma,
Allergy and Immunology, tells WebMD, "The bottom line is, 'Is it a
legitimate risk factor?' ... It is going to take a lot more information before
we can determine that."
Camargo acknowledges many of the same study limitations that these critics
raise. Moreover, he points out that it took a long time before doctors believed
that dust mites and cockroaches played a role in asthma. He worries that it may
take a while before doctors are convinced of the role of obesity.
- A new study shows that a high body mass index (BMI) is associated with a
higher risk of developing adult-onset asthma.
- Earlier findings have already shown that childhood asthma is more prevalent
in overweight populations.
- Some experts point to the limitations of the study, saying that the
association could be explained by other variables.