The authors examined 45 patients with polymyositis or dermatomyositis (PM/DM) in cross-sectional, retrospective study. The disease was active in all the patients who were treated with a mean daily dose of 21.8 mg 5 ± 19.1 of prednisone or its equivalent. The mean duration of the disease was 5 years and 4 months. Twenty-one from 45 patients (46,7 %) had vertebral fractures verified by X-ray. Mean age of patients was 51.5 ± 13.8 years. Evaluation of bone mineral density revealed osteoporosis in 22% and osteopenia in 34% patients. It was observed that patients with fractures were older and duration of the disease was longer when PM/DM groups with and without fractures were compared. The relation between corticosteroid daily and cumulative dose and fracture occurrence was not found. There was no significant difference in biochemical markers in groups with and without fractures as well. The authors conclude that glucocorticoid-induced osteoporosis is a serious issue which in PM/DM has probably multifactorial causes. Treatment with bisphosphonates is recommended already when BMD decreased to -1.5 SD.

        Key words: glucocorticoid-induced OP, polymyositis, dermatomyositis