Long-term use of a drug commonly used to treat asthma and emphysema may lead to the bone-thinning disease osteoporosis.

Researchers found that after three years of using an inhaled steroid, emphysema patients had a significant loss in bone density.

The results may add fuel to an already controversial matter. Previous studies examining the link between inhaled steroids and bone density loss have offered conflicting results.

Some studies have shown little to no bone loss after years of use. But others have shown that long-term use of inhaled steroids can weaken bones and possibly increase the chance of breaking a bone.

Inhaled steroids are the best treatment for people with moderate to severe asthma. They help calm the airway inflammation seen in asthma and decrease the risk of having an asthma attack. They are also frequently used to treat the lung disease emphysema, which usually occurs after many years of smoking.

Examples of inhaled steroids include: Advair, Aerobid, Azmacort, Flovent and Pulmicort.

In this new study, researchers looked at patients taking Azmacort. The findings appear in today’s issue of the American Journal of Respiratory and Critical Care Medicine.

Lead researcher Paul Scanlon, MD, of the Mayo Clinic in Rochester, Minn., studied 412 current smokers or recent quitters. They all had mild to moderate emphysema. Each person took either Azmacort - six puffs twice a day of the 100 microgram dose - or a placebo.

The patients underwent bone mineral density scans of the hip and lumbar spine at the start of the study and again after three months, one year, and three years. This is the most common test to determine osteoporosis risk.

Bone Loss Seen After One Year

No bone loss was seen at three months, but some bone loss was evident after one year. After three years, the Azmacort patients had lost significantly more bone mineral density in the spine than the placebo patients. Women had more bone loss in the spine than men.

A loss in bone mineral density can lead to osteoporosis. Many emphysema patients already have risk factors for osteoporosis, including smoking, a sedentary lifestyle, older age, and bad diets.

The researchers did not find an increase in fractures during the three-year study.

It’s unclear if the bone loss would continue after three years. However, continued bone loss would very possibly lead to fractures.

In light of their findings, Scanlon and colleagues emphasize that the benefits of inhaled steroids for emphysema patients must be carefully weighed against the potential risk of osteoporosis. They also suggest that bone-building medications should be considered.

Preventing Bone Loss

In addition to bone-building medications, there are several things you can do to maintain or build bone.

Exercise. Weight-bearing exercise such as jogging, playing tennis, and weight lifting makes bones and muscles stronger and helps prevent bone loss.

High-calcium foods. Getting enough calcium throughout your life helps build and keep strong bones. Excellent sources of calcium are milk and dairy products (low-fat versions are recommended); a variety of seafood, such as canned fish with bones like salmon and sardines; dark green leafy vegetables such as kale, collards, and broccoli; calcium-fortified orange juice; and breads made with calcium-fortified flour.

Calcium supplements. People that don’t like dairy or other high-calcium foods may need to take calcium supplements. Check with your doctor to see how much you may need.

Vitamin D. Your body uses vitamin D to absorb calcium. Being out in the sun for 20 minutes every day helps most people’s bodies make enough vitamin D. You can also get vitamin D from eggs, fatty fish like salmon, cereal, and milk fortified with vitamin D, as well as from supplements.

By Kelli Miller Stacy, reviewed by Michael W. Smith, MD