To investigate the trajectory of primary hyperparathyroidism (PHPT) and normocalcaemic hyperparathyroidism (NHPT) on bone mineral density (BMD).
To also investigate the effect of management on PHPT and NHPT:
Patients from an osteoporosis service were retrospectively reviewed (2018-2023). Of the 831 patients registered in this service, 64 patients were included for the study: PHPT 21 (33%), NHPT 23 (36%), and controls 20 (31%). Biochemistry, skeletal outcomes, and surgical data were collected before and after therapy (medical, surgical, or conservative). Least significant change represented the smallest difference between successive BMD measurements and the threshold was 5%.
57% of PHPT and 13% of NHPT underwent a parathyroidectomy. BMD demonstrated improvement with medical therapy for the wrist and spine (PHPT) and improvement with medical therapy for the spine and right hip and right hip with surgical therapy for NHPT. Improvement in vitamin D levels didn’t produce resolution of PTH levels in PHPT or NHPT. There was a significant reduction in PTH (11.0 to 6.2pmol/L, p=.043) and cCa (2.7 to 2.4mmol/L, p<.004) for PHPT but not in NHPT following surgical management. There was no significant change in mean PTH (10.5 to 10.3pmol/L, p=.672) or cCa (2.7 to 2.6mmol/L, p=.120) in the PHTP group following medical management compared to NHPT where there was a significant change in PTH (10.2 to 8.5pmol/L, p=.027) but not cCa (2.3 to 2.4mmol/L, p=.067). Proximal forearm fractures were most common across the three groups.
Medical management was not inferior to surgical management in the skeletal outcomes for NHPT. Multiglandular disease was more common in NHPT compared to PHTP group (67% vs. 25%). Treating vitamin D insufficiency did not appear to improve the hyperparathyroidism in either PHPT or NHPT.