Inhaled corticosteroid use and bone-mineral density in patients with asthma

Background Inhaled corticosteroids are absorbed into the systemic circulati on, but the extent to which they have adverse effects on bone is uncertain. The question is important since 3% of the European population take an inha led corticosteroid regularly and may do so for many years. Methods We studied the dose-response relation between cumulative inhaled co rticosteroid dose and bone-mineral density at the lumbar spine and proximal femur in 196 adults (119 women) with asthma aged 20-40 years. Patients had taken an inhaled corticosteroid regularly for at least 6 months, and had h ad limited exposure to systemic steroids. Cumulative dose of inhaled cortic osteroid was calculated from questionnaires and computerised and written ge neral-practice records, and its effect on bone-mineral density was estimate d by multiple regression analysis. Findings Median duration of inhaled corticosteroid treatment was 6 years (r ange 0.5-24), and median cumulative dose was 876 mg (87-4380), There was a negative association between cumulative dose of inhaled corticosteroid and bone-mineral density at the lumbar spine (L2-L4), femoral neck, Ward's tria ngle, and trochanter, both before and after adjustment for the effects of a ge and sex. A doubling in dose of inhaled corticosteroid was associated wit h a decrease in bone-mineral density at the lumbar spine of 0.16 SD (95% CI 0.04-0.28). Similar decreases were found at the femoral neck, Ward's trian gle, and trochanter, Adjustment for potential confounding factors including physical activity and past oral, nasal, dermal, and parenteral corticoster oids did not weaken the associations. Interpretation This study provides evidence of a negative relation between total cumulative dose of inhaled corticosteroid and bone-mineral density in patients with asthma.