The risk of adrenal insufficiency -- the inability of the adrenal gland to produce adequate amounts of cortisol in response to stress -- may increase with the use of oral corticosteroids, according to a study published in the British medical journal Thorax.

The case-control study was performed using computerized general practice data from the UK-based Health Improvement Network. From a cohort of 2.4 million people, 154 cases of adrenal insufficiency and 870 controls were identified. There was a dose-related increased risk of adrenal insufficiency in people prescribed an oral corticosteroid with an odds ratio of 2.0 per course of treatment per year, the study found.

People prescribed an oral or inhaled corticosteroid were at a dose-related increased risk of adrenal insufficiency, the study concluded. It added, however, that the absolute risk was small. This suggests, the study notes, that the increased risk in people prescribed an inhaled corticosteroid is largely due to oral corticosteroid exposure, but inhaled corticosteroids may have an effect when they are taken at higher doses.