BONE-MINERAL DENSITY AND THE RISK OF FRACTURE IN PATIENTS RECEIVING LONG-TERM INHALED STEROID-THERAPY FOR ASTHMA

To determine whether high-dose or prolonged inhaled steroid therapy fo r asthma increases a patient's risk of osteoporosis and fracture, we m easured bone density in 26 men and 43 women (41 postmenopausal, all of whom had received supplemental estrogen therapy) after treatment with an inhaled steroid for 10.1 +/- 5.5 years and oral prednisone for 10. 7 +/- 9.7 years (mean +/- SD). Most had stopped receiving prednisone s ince commencing the inhaled steroid therapy. We found that bone densit ies (adjusted for age and sex to yield a z score) were lower in associ ation with higher daily doses of inhaled steroid (p = 0.013 ANCOVA) an d with the duration of past prednisone therapy (p = 0.032). Larger cum ulative inhaled steroid doses were associated with higher bone densiti es (p = 0.002) and a reduction in the numbers of patients at risk of f racture. Bone density also increased with the amount of supplemental e strogen therapy (p = 0.058) and, at equivalent levels of inhaled and o ral steroid use, women showed higher bone density z scores es than did men. Women with a lifetime dose of inhaled steroid greater than 3 gm had normal bone density regardless of the amount of past or current pr ednisone use oi the current dose of inhaled steroid. These data indica te that the daily dose, brit not the duration, of inhaled steroid ther apy may adversely affect bone density, and that estrogen therapy may o ffset this bone-depleting effect in postmenopausal women.