Abstract
BACKGROUND: This 3-year retrospective study compared the outcomes of bisphosphonate-pretreated denosumab therapy with or without vitamin D and calcium supplementation in postmenopausal osteoporosis (OP) patients with rheumatoid arthritis (RA). MATERIALS AND METHODS: Fifty-eight patients under long-term denosumab treatment were divided into groups without (denosumab group; 31 cases) or with (combination group; 27 cases) vitamin D and calcium supplementation. The bone markers of BAP, TRACP-5b, and urinary NTX were measured at baseline and every year for 3 years. We also evaluated bone mineral density (BMD) of the lumbar 1-4 vertebrae (L-BMD) and bilateral total hips (H-BMD) at the same time points. RESULTS: There were no significant differences in the percent changes of serum albumin-corrected calcium between the groups. The percent change in TRACP-5b was significantly higher in the combination group at 2 years. Serum 25-hydroxyvitamin D status was persistently high during therapy in both groups, with significant percent increases over baseline at 2 and 6 months in both groups and at 24 months in the combination group. The percent increase from baseline of serum zinc was significantly higher at 3 years in the combination group over the denosumab group. L-BMD and H-BMD were significantly increased at every time point for 3 years vs pretreatment levels in both groups and were significantly higher in the combination group at all time points. CONCLUSION: Compared with denosumab monotherapy, the combination group displayed significantly increased serum zinc, L-BMD, and H-BMD at 3 years in OP patients with RA. Thus, calcium and vitamin D supplementation may be beneficial to enhance BMD gains, but not necessarily 25-hydroxyvitamin D status, in patients with OP and RA under denosumab.