Significant improvement of bone mineral density by denosumab without bisphosphonate pre-treatment in glucocorticoid-induced osteoporosis.

OBJECTIVE: The aim of this study was to evaluate differences in outcomes of denosumab for a year with or without bisphosphonate (BP) pre-treatment in patients with glucocorticoid-induced osteoporosis (GIO).

METHODS: Forty-eight female patients with GIO and low bone mineral density (BMD) (T score of BMD; less than -3.0 SD) were, retrospectively, enrolled and classified into the following two groups: (1) GIO with BP pre-treatment (BP pre-treated group; n = 24) and (2) GIO without BP treatment (BP pre-untreated group; n = 24). We measured serum bone alkaline phosphatase (BAP), N-terminal propeptide of type 1 procollagen (P1NP), and tartrate-resistant acid phosphatase (TRACP)-5b at baseline, and at 3, 6, and 12 months. We also assessed BMD of the lumbar 1-4 vertebrae BMD (L-BMD) and bilateral hip BMD (H-BMD) at baseline, and at 6 and 12 months.

RESULTS: TRACP-5b was significantly inhibited at 3 months in both groups and at 6 and 12 months in the BP pre-untreated group compared with pre-treatment levels. Both BAP and P1NP were significantly suppressed at 3, 6, and 12 months in both groups compared with baseline values. L-BMD and H-BMD were significantly increased at 6 (4.2% and 3.4%, respectively) and 12 months (4.7% and 4.7%, respectively) in the BP pre-untreated group over pre-treatment levels. There were no significant differences between the groups during the observational period.

CONCLUSION: Denosumab significantly improved both L-BMD and H-BMD in the BP pre-untreated group, but not in the BP pre-treated group, suggesting it to be a good option for GIO patients without BP pre-treatment.