Bone turnover markers (BTMs) are recommended as an important tool in follow-up of osteoporosis treatment. However, there is a lack of knowledge in the reliability of BTMs during and after glucocorticoid treatment. Glucocorticoids suppresses BTMs during treatment with at least 30% and, moreover, glucocorticoids increase the risk of fractures. Patients with an inflammatory joint disease are at increased risk of osteoporosis, and disease flares are often treated with glucocorticoids, which in turn can lead to loss in reliability of the BTMs in patients who also are on osteoporosis treatment. There is a need of more knowledge on BTM changes during and after glucocorticoid treatment for optimized patientcare, reduced risk of side effects and reduced health economic costs.