Glucocorticoid-induced osteoporosis: treatment update and review

Glucocorticoid-induced osteoporosis (GIO) is a serious consequence of glucocorticoid therapy leading to fractures in 30-50% of patients. A wide range of protective medications have been studied in this condition including calcium, vitamin D, vitamin D analogs, oral and intravenous bisphosphonates, sex hormones, anabolic agents and calcitonin. The mechanism of action, and evidence for these therapies, are reviewed - focusing on important trials and new evidence. Recently published guidelines are also reviewed and compared. Bisphosphonates are currently the recommended first-line therapy for the prevention and treatment of GIO. They have been shown to increase bone mineral density (BMD) at the spine and hip and to decrease the incidence of vertebral fractures (especially in postmenopausal women). Testosterone therapy and female hormone replacement therapy (HRT) have been found to increase lumbar spine BMD in hypogonadal patients on glucocorticoid therapy, but effects on hip BMD have not been consistent and there is no fracture data in the GIO population. Similarly, calcitonin increases lumbar spine BMD but has no proven fracture efficacy. The effect of selective estrogen receptor modulators, the oral contraceptive pill and strontium on GIO is relatively unknown. Parathyroid hormone (PTH 1-34) and zoledronic acid have emerged as exciting new options for the treatment of GIO. Both therapies have been found to result in gains in BMD at the spine and hip that are either noninferior or superior to those seen with oral bisphosphonate therapy. PTH 1-34 has also been found to decrease the incidence of new vertebral fractures and may be an option in high-risk patients established on long-term glucocorticoid therapy.