Inhaled corticosteroids, bone mineral density and fracture in older people

The efficacy of inhaled corticosteroids in the treatment of asthma has been firmly established in a variety of settings. The majority of asthma management plans now recommend the use of inhaled corticosteroids at an early stage. This means that most patients with asthma will be prescribed an inhaled corticosteroid at some point in time and many patients with asthma will use these drugs for several years. Inhaled corticosteroids are also used in the treatment of other conditions, particularly chronic obstructive pulmonary disease (COPD). Since inhaled corticosteroids are absorbed into the systemic circulation, they can have systemic adverse effects, such as suppression of the hypothalamic-pituitary-adrenal axis and increasing the risk of bruising. However, perhaps the greatest concern for patients is whether the regular use of inhaled corticosteroids has an adverse impact on the bone mineral density and increases the risk of fracture. There is now accumulating evidence from epidemiological studies that the use of inhaled corticosteroids is inversely related to bone mineral density in a dose-dependent fashion. However, data from two clinical trials of moderately high doses of inhaled corticosteroids in patients with COPD have produced conflicting results and while the larger study of triamcinolone found a significant impact of this drug on bone mineral density, a smaller study of budesonide found no effect. Epidemiological research into the relationship between inhaled corticosteroids and fracture is at an early stage. To date, only three studies in this area have been reported, all of which have used different approaches to try to minimise the impact of bias and confounding. There is a lack of consistency between the final estimates of the impact of inhaled corticosteroids on fracture risk. However, taken together these data suggest that the short to medium term use of inhaled corticosteroids is associated with a small adverse effect on bone. Doctors and patients need to be aware of this risk and balance it against the known beneficial effects of inhaled corticosteroids.