Premenopausal
women who use inhaled corticosteroids to treat persistent asthma may experience
accelerated bone loss in the hip compared to those who do not use inhaled
steroids, according to results of a new study of 109 women ages 18 to 45
years old.
In the September
27, 2001, issue of the New England Journal of Medicine (NEJM), researchers
at Brigham and Women's Hospital (BWH) in Boston report that the effect
of the inhaled steroids was directly related to the dose -- that is, the
bone density loss increased with the number of puffs per day and persisted
throughout the three-year study.
Although the
yearly changes were small, the scientists suggest that the long-term cumulative
effect could ultimately put some women at high risk of hip fracture. The
study was supported by the National Heart, Lung, and Blood Institute (NHLBI)
and the National Center for Research Resources-both components of the National
Institutes of Health.
Inhaled steroids
are the recommended treatment for persistent asthma, according to NHLBI's
1997 Guidelines for the Diagnosis and Management of Asthma , because they
reduce the airways' inflammation and sensitivity to certain irritants and
allergens that contribute to asthma symptoms.
"As with all treatments,
the goal is to maximize the benefits and minimize the risks," says NHLBI
Director Dr. Claude Lenfant. "It is important to recognize that poor
asthma control can lead to complications. Research has found repeatedly
that compared to other medical therapies, inhaled steroids provide the
best daily control of persistent asthma."
Measuring bone
density at baseline, six months, and annually thereafter, the researchers
compared the results among women who used inhaled triamcinolone acetonide,
a steroid, at two dosage levels (4 to 8 puffs per day versus more than
8 puffs per day) and those who did not use inhaled steroids.
They found that
those using the inhaled steroids had decreased bone density in the hip
but not in the spine or femoral neck (part of the thigh leading to the
hip). The rates of bone density loss varied among the women taking inhaled
steroids, but the effects were greater with higher dosages and longer duration
of treatment.
"The effect
of inhaled steroid use on bone density was shown to be dose related," notes
Lenfant. "We encourage all patients with asthma to work with their doctors
on a comprehensive treatment plan; that is, the lowest possible dose of
inhaled steroids that controls their asthma symptoms as well as measures
to maintain good bone health, such as adequate calcium and vitamin D intake."
One option to
lower steroid dosage is to supplement therapy with long-acting beta-agonists.
Two studies by the NHLBI Asthma Clinical Research Network recently found
that adult men and women with mild-to-moderate persistent asthma who used
both medications were able to reduce steroid dosage, on average, by 50
percent without losing symptom control.
Those treated
with long-acting beta-agonists alone, however, suffered from significantly
worse symptoms compared to those treated with inhaled steroids alone or
with both medications.
These findings
were reported in the May 23, 2001, issue of the Journal of the American
Medical Association .
Another recent
study, NHLBI's Childhood Asthma Management Program, found that inhaled
steroids offered superior control with no long-term effect on bone density,
as reported in the October 12, 2000, NEJM . In this five-year study
of children ages 5 to 12 years, investigators found a small but temporary
reduction in the rate of growth of those treated with inhaled steroids.
In general,
results of earlier studies on the effect of inhaled steroids on bone density
have been conflicting, although long-term use of oral steroids has conclusively
been associated with accelerated bone loss and increased rate of fractures.
The September
27, 2001, NEJM research report found the effects of inhaled steroids independent
of oral steroid use or other conditions that could affect bone density.
Asthma is a
chronic lung disease that affects more than 15 million Americans.
It is currently
estimated to cost the U.S. economy $12.3 billion a year in health care
costs and lost productivity.
--
Copyright 2001 by United
Press International.
All rights reserved.
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