A randomized controlled trial of salmon calcitonin to prevent bone loss in corticosteroid-treated temporal arteritis and polymyalgia rheumatica

Patients treated with high-dose or long-term corticosteroids are at risk of accelerated osteoporosis and spontaneous vertebral and traumatic fractures. To assess the efficacy of salmon calcitonin in preventing corticosteroid-induced osteoporosis, 48 patients with newly diagnosed polymyalgia rheumatica, temporal arteritis, and other vasculitides were enrolled in a 2-year, double-blind, randomized, controlled trial. Patients were randomized to receive subcutaneous injections t.i.w. of either 100 IU of salmon calcitonin (25 patients) or placebo (23 patients). After 2 years, 19 and 21 patients, respectively, were evaluable. All patients also received supplemental calcium carbonate (1500 mg daily in divided doses) and vitamin D-3 (400 IU daily). Baseline and serial radiologic assessments included dual-energy X-ray absorptiometry (DXA) of the lumbar spine and hip, and spine radiographs to detect vertebral fractures, There were no significant baseline differences between the two study groups. The mean within-subject percentage change in DXA lumbar spine density in the two groups over the 2-year period of the study was only -0.1% (calcitonin plus calcium) versus -0.2% (placebo plus calcium) a nonsignificant difference despite the high mean cumulative corticosteroid doses of 5371 mg and 4680 mg, respectively (NS). The incidence of vertebral fracture was 12.5% (calcitonin plus calcium: 11%, versus placebo plus calcium: 14%, NS), with four fractures in the first year and one fracture in the second year. Higher cumulative corticosteroid dose was associated with a greater loss in bone density. In rheumatic disease patients starting high-dose, longterm corticosteroids, salmon calcitonin with calcium and vitamin D, provided no greater bone preservation than that observed with calcium and vitamin D-3 alone.