MEDIA RELEASE
22nd February 2007
Take aspirin regularly to reduce your chances of getting
asthma
If, as an adult, you take a daily aspirin, you may well prevent
yourself from developing asthma. That’s the message from
a new analysis of the well-known American Physician’s Health
Study . The Study, which followed more than 22,000 American male
doctors, who were apparently healthy at the start of the study,
is already famous for its reports on the benefits of a daily aspirin
in preventing heart disease. After just under five years, for
example, one ‘arm’ of the study – a comparison
of a daily aspirin with placebo (a dummy tablet) – was stopped
because the doctors taking the aspirin had 44 percent fewer heart
attacks than those taking the placebo. It was largely from this
study that we now give aspirin routinely to people at risk of
heart attacks.
However, its protection against asthma may be more surprising.
That’s because we know that for a small proportion of people
(between 4 and 11 percent) with asthma, aspirin makes the asthma
worse and can even induce an acute asthma attack. For that reason
aspirin is rarely advised for people who already have the illness.
So why should we expect aspirin to prevent the start of asthma
in adults? Several studies have previously suggested that people
who take daily aspirin might be less likely to develop new asthma
than expected . In asthma there is inflammation in the lungs,
and aspirin is known to be a powerful anti-inflammatory agent,
so that there is a theoretical rationale for its use. However,
there was a need for this suggestion to be confirmed in a larger,
well-controlled study.
The Physician’s Health Study has provided that confirmation.
The doctors, none of whom had ever had asthma before entering
the study, were asked to take aspirin every day for 18 weeks before
starting on the study. None reacted badly (either with asthma
or in any other way) to aspirin in this ‘run in’ period.
They were then put in one of two groups of equal numbers. Half
took daily aspirin and half took placebo. Over the next 4.9 years,
145 taking placebo and 113 taking aspirin developed asthma. This
meant that 22 percent fewer men on aspirin than on placebo started
to have the illness – a difference that was calculated statistically
to be highly significant. When the authors compared men who took
more than 15 aspirin tablets a month over the length of the study
with those who never took aspirin the protection rose to 40 percent.
The authors concluded that aspirin may reduce the risk of the
development of asthma in adults. This doesn’t imply, however,
that aspirin can improve symptoms in people who already have asthma.
Indeed it may make a small proportion of people with asthma worse.
They make a further point. Numbers of cases of asthma have risen
steeply in the last thirty years in the United States, Britain
and Australia. The authors postulate that there may be a link
between this rise and the fact that we no longer give aspirin
to children in these countries. Paracetamol is used instead. There
are biochemical reasons to suppose that aspirin may specifically
prevent asthma-inducing changes in the lungs of some children,
and without the drug, many more children may have developed it
than would otherwise have done so .
Ends
1.Barr RG Kurth T Stampfer
MJ et al. Aspirin and Decreased Adult-Onset Asthma Am J Respir
Crit Care Med 2007; 175:120-5
2. Barr RG Wentowski
CC et al. Prospective study of acetaminophen use and risk
of newly diagnosed asthma among women. Am J Respir Crit
Care Med 2004; 169: 836-41
3. Varner AE Busse WW
Lemanske RFJ. Hopothesis: decreasing use of pediatric aspirin
has contributed to the increasing prevalence of childhood asthma.
Ann Alergy Asthma Immunol 1998; 81: 347-51.
