The ineffectiveness of cyclical oral clodronate on bone mineral density in glucocorticoid-treated patients with giant-cell arteritis

Objectives and design. The aim of the present study was to determine whether cyclic oral administration of clodronate, a bisphosphonate, every second month prevents rapid bone loss during the first year of glucocorticoid treatment in patients with giant-cell arteritis (GCA). The trial was designed as a prospective double blind study, assessing total body mineral content (BMC) and bone mineral density (BMD) using DXA technique. Supplementation of calcium was given to both groups of patients. Setting. The outpatient clinics of the rheumatic and infectious diseases of Sahlgren University Hospital of the city of Goteborg on the west coast of Sweden. Subjects. Twenty-seven patients with confirmed GCA were consecutively included during a 15-month period. Results. An early influence on bone turnover was found with a temporary decrease in BMC after six months of glucocorticoid treatment, which was normalized after 12 months in both study groups. No significant differences between the patients given clodronate and calcium and the controls, who got supplementation with calcium alone, was observed at any assessment point. However, there was a significant and prolonged depression of the osteocalcin levels in the clodronate-treated patients. Conclusions. Oral administration of clodronate in a moderately high dose given cyclically every other month had no additive effect on BMD compared with calcium supplementation alone during the first year of glucocorticoid treatment. A larger material might have revealed some differences between the categories. In most patients with GCA, however, the BMD seems to recover after one year of glucocorticoid treatment, provided there is good control of the inflammation and patients are kept physically active. It needs to be elucidated whether there are subsets of patients who might benefit from bone sparing agents: women near menopause with a high turnover rate of bone, individuals who have low BMD from the start of glucocorticoid treatment or patients requiring high doses of glucocorticoids during a long period of time.