Short-term bisphosphonate treatment reduces serum 25(OH) vitamin D3 and alters values of parathyroid hormone, pentosidine, and bone metabolic markers

Unexpected rapid increase in bone mineral density by bisphosphonate therapy after multiple spinal fractures: a case report

Background

Osteoporosis is a serious disease that causes bone fragility fractures and increases mortality. Bisphosphonates are the first-line drugs for osteoporosis. However, the gains in bone mineral density by use of bisphosphonates alone are limited.

Case presentation

We describe the clinical outcome of a Japanese woman with osteoporosis treated with bisphosphonates after multiple spinal fractures. After 3 years of treatment with the bisphosphonate alendronate, her lumbar bone mineral density and bilateral hip bone mineral density markedly increased by 61.9% and 32.5%, respectively.

Conclusion

We considered that our patient’s multiple fractures had caused a decrease in bone mineral density, which naturally improved with fracture healing to enhance the increase in bone mineral density with bisphosphonate treatment.

Calcium and vitamin D supplementation with 3-year denosumab treatment is beneficial to enhance bone mineral density in postmenopausal patients with osteoporosis and rheumatoid arthritis

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.

Increased Serum 25(OH)D3 Levels in Post-Menopausal Japanese Women with Osteoporosis after 3-Year Bisphosphonate Treatment

Osteoporosis is characterized by the systemic impairment of bone mass, strength, and microarchitecture, leading to an increased risk of fragility fracture. Bisphosphonates (BPs) are the first-line drugs for osteoporosis. Vitamin D is considered to be essential for osteoporotic treatment. However, long-term effects of BPs on the serum levels of 25-hydroxyvitamin D₃ (25(OH)D₃) are unknown. Accordingly, in this retrospective study, we collected clinical data of 41 post-menopausal Japanese women with osteoporosis treated with BP for over 3 years, without vitamin D supplementation. We measured lumbar and femoral neck bone mineral density (BMD) and serum levels of bone specific alkaline phosphatase (BAP) as a bone formation marker, and tartrate-resistant acid phosphatase (TRACP)-5b as a bone resorption marker, before and after the 3-year treatment. Serum 25(OH)D₃, 1,25(OH)₂D₃, and whole parathyroid hormone (PTH) were also measured. Notably, no fracture occurred during the treatment. Compared with baseline values, 25(OH)D₃ levels were significantly increased from 21.6 to 26.4 ng/mL (P = 0.006), despite no vitamin D supplementation. 1,25(OH)₂D₃ and whole PTH levels tended to be decreased from 62.6 to 57.8 pg/mL and 27.3 to 25.1 pg/mL, respectively. Both bone formation and resorption markers were significantly suppressed (P < 0.01). Both lumbar BMD (7.3% increase) and femoral neck BMD (4.1% increase) were significantly improved (P < 0.0001) after 3 years of the treatment. Thus, even without vitamin D supplementation, serum 25(OH)D₃ levels were significantly increased after 3-year BP therapy. These results suggest that vitamin D supplementation might not be required in the long-term BP therapy for osteoporosis.

Minodronate for the treatment of osteoporosis

Minodronate is a third-generation bisphosphonate that was developed and approved for clinical use in osteoporosis therapy in Japan. The mechanism of action for suppressing bone resorption is the inhibition of farnesyl pyrophosphate synthase, a key enzyme in the mevalonic acid metabolic pathway of osteoclasts, to induce apoptosis of the cells. Minodronate is the strongest inhibitor of bone resorption among the currently available oral bisphosphonates. Large randomized, placebo-controlled, double-blind clinical trials have revealed an increase in bone mineral density of both the lumbar spine and femoral neck over 3 years of daily minodronate therapy and risk reduction in vertebral fractures over 2 years of therapy. The increase in bone mass and the prevention of vertebral fractures are similar to those with alendronate or risedronate. The incidence of adverse events, especially gastrointestinal disturbance, is the same as or less than that with weekly or daily alendronate or risedronate. The unique mechanism of action of minodronate via the inhibition of the P2X(2/3) receptor compared with other bisphosphonates may be an advantage in reducing low back pain in patients with osteoporosis. The monthly regimen of minodronate, introduced in 2011, is expected to have better patient adherence and longer persistence. In experimental animal models, minodronate preserved, or even ameliorated, bone microarchitectures, including microcracks and perforation of the trabeculae in the short term. The lowest incidence of bisphosphonate-related osteonecrosis of the jaw among all bisphosphonates and the lack of atypical femoral fractures attributed to its use to date, however, are partly because only a smaller population used minodronate than those using other bisphosphonates. To date, minodronate is available only in Japan. Hip fracture risk reduction has not been verified yet. More clinical studies on minodronate and its use in osteoporosis treatment, with a large number of subjects, should be conducted to verify hip fracture risk reduction and long-term results.