Inhaled corticosteroids--effect on bone?

Asthmatic patients receiving long-term therapy with oral prednisolone have been found to have an increased incidence of vertebral fractures. Measurements of bone density have shown that diminished bone density is associated with administration of oral corticosteroids rather than with the disease. Inhaled corticosteroids have some systemic activity and although serum calcium and parathyroid hormone levels are unaffected by corticosteroids, inhaled corticosteroids at doses of more than 1.0 mg day-1 have measurable effects on bone metabolism in normal subjects.