Effects of denosumab as compared with parathyroidectomy regarding calcium, renal, and bone involvement in osteoporotic patients with primary hyperparathyroidism

To evaluate the effects of denosumab (Dmb) on calcium, renal, and bone involvement in osteoporotic patients with primary hyperparathyroidism (PHPT) and compare with those who underwent a parathyroidectomy (PTX) procedure.

This retrospective, longitudinal study included patients treated with Dmb (60 mg) once every 6 months (n = 19) and those who successfully underwent a PTX procedure (n = 19) corrected calcium (cCa), eGFR, bone mineral density (BMD) in the lumbar spine (LS), total hip (TH), and femoral neck (FN) and LS-trabecular bone score (TBS) changes at 1 year after beginning Dmb or undergoing PTX were measured.

Dmb group had older age, and showed milder disease activity and lower eGFR as compared with PTX group. In PTX group, cCa and eGFR were significantly decreased following surgery, while those were stable in Dmb group. There were significant increases in LS, TH, and FN-BMD in both Dmb (LS: 6.0 ± 0.8%, TH: 3.7 ± 1.0%, FN: 4.3 ± 1.5%) and PTX (LS: 11.2 ± 1.5%, TH: 7.5 ± 1.5%, FN: 7.9 ± 2.1%) groups. In Dmb group, LS-TBS was significantly improved by 3.0 ± 1.0%, while TBS change in PTX group approached significance (2.8 ± 1.5%). Percent change in TH-BMD was significantly correlated with baseline tartrate-resistant acid phosphatase-5b (TRACP-5b) in both groups.

Dmb treatment not only increased BMD, dependent on bone turnover status, the same as PTX, but also improved LS-TBS. In addition, it did not decrease the level of eGFR, whereas PTX did. These results suggest that Dmb treatment help in the clinical management of osteoporotic patients with PHPT who do not undergo surgery as alternative to PTX.