Adrenal insufficiency is a clinical condition that is associated with a deficiency of adrenal hormones, mainly: glucocorticoids and mineralocorticoids. Cushing syndrome is also a condition that stems from the existence of persistent high cortisol level in the body. The majority of Cushing syndrome cases are exogenous (iatrogenic or due to use of medication).~Glucocorticoids are widely used for the treatment of chronic inflammatory diseases. Although glucocorticoids are effective in controlling disease symptoms, continuous use of the drugs can lead to suppression of adrenal hormones or excessive cortisol level in the blood stream. That is, excess blood cortisol level due to glucocorticoid exogenous supply can either inhibit the 'hypothalamus-pituitary-adrenal axis' for adrenal hormones production or result in Cushing symptoms.~In the period between 1989 and 2008 in the UK, it was estimated that 0.6%-0.8% of the general adult population were long-term users of oral glucocorticoids. However, there is no data on the risk of adrenal suppression and Cushing syndrome due to chronic use of glucocorticoids in the UK to date~The aim of the study is to investigate the risk of adrenal insufficiency and Cushing syndrome due to long-term use of glucocorticoids in England. This is a retrospective cohort study of people diagnosed with at least one of six chronic inflammatory diseases (polymialgia rheumatica, giant cell arteritis, systemic lupus erythematosus, rheumatoid arthritis, vasculitis and inflammatory bowel disease).~This study will be based on the analysis of existing primary care health records routinely collected, linked to hospital and mortality data.
Glucocorticoids are widely used for the treatment of chronic inflammatory diseases. Although glucocorticoids are effective in controlling disease symptoms, continuous use of the drugs can lead to suppression of adrenal hormones or excessive cortisol level in the blood stream. That is, excess blood cortisol level due to glucocorticoid exogenous supply can either inhibit the 'hypothalamus-pituitary-adrenal axis' for adrenal hormones production or result in Cushing symptoms.~In the period between 1989 and 2008 in the UK, it was estimated that 0.6%-0.8% of the general adult population were long-term users of oral glucocorticoids. However, there is no data on the risk of adrenal suppression and Cushing syndrome due to chronic use of glucocorticoids in the UK to date.~The aim of the study is to investigate the risk of adrenal insufficiency and Cushing syndrome due to long-term use of glucocorticoids in England.