Prophylaxis and Treatment of Glucocorticoid-induced Osteoporosis

Glucocorticoid-induced osteoporosis (GC-OP) is one of the most frequent forms of osteoporosis. Based on epidemiological investigations, 0.5-0.9% of the community population use oral glucocorticoids (GC); in persons aged 50 or more, the number of GC users is about 3%. The fracture risk is increased twofold in patients with chronic GC treatment and is even higher for vertebral fractures because GCs predominantly affect trabecular bone. The pathogenetic origin of GC-OP is a loss of bone mass and quality resulting from the suppressive effects of GC on the number and function of osteoblasts and osteocytes and an increase in bone resorption. Systemic effects inducing sarcopenia with an increased risk of falls, hormonal changes and a negative calcium balance may further amplify the unfavourable effects of GCs on bone. Basic diagnostic evaluation for osteoporosis including osteodensitometry is indicated when GC treatment with a minimum daily dose of 2.5 mg/d prednisolone equivalent is planned for more than 3 months. The fracture risk is already increased in the first 3 months of GC treatment. Therefore an early intervention to prevent GC-induced loss of bone mass is necessary. The guidelines given by the umbrella organisation of the German osteology societies provide the foundation for prophylaxis and treatment of GC-OP based on the calculated fracture risk. General measures include the prevention of falls and improvement of muscle mass and coordination as well as a sufficient supply of calcium and vitamin D. The indication for specific drug treatment exceeding these basic measures depends on the individual fracture risk, which is determined by daily GC dose, duration of GC treatment, age, gender and other risk factors including the underlying disease that is treated with GC. For the implementation of the recommendations, particularly in the prophylactic approach, the calculation of the duration and dose of planned GC treatment is essential. In this context the guidelines for treatment of the different inflammatory rheumatic diseases provide crucial orientation. Treatment with GC doses of >= 7.5 mg/d prednisolone equivalent for more than 3 months requires specific drug treatment if T scores are < - 1.5 or if low-traumatic vertebral fractures or multiple peripheral fractures are present. GC doses between 2.5 und 7.5 mg/d require a lowering of the treatment threshold, which is determined by age, gender and other risk factors. A prevention of GC-induced loss of bone mass and vertebral fractures has been shown for bisphosphonates and teriparatide. Bisphosphonates are particularly suitable for prevention, while teriparatide is useful for the treatment of severe osteoporosis with prevalent fractures. A more consistent implementation of the recommendations for prophylaxis and treatment of GC-OP is crucial.