Schini, M. orcid.org/0000-0003-2204-2095, Jacques, R. orcid.org/0000-0001-6710-5403, Oakes, E. et al. (3 more authors) (2020) Normocalcemic hyperparathyroidism : study of its prevalence and natural history. The Journal of Clinical Endocrinology & Metabolism, 105 (4). dgaa084. ISSN 0021-972X
Abstract
Context
Normocalcemic hyperparathyroidism (NPHPT) is characterized by persistently normal calcium levels and elevated parathyroid hormone (PTH) values, after excluding other causes of secondary hyperparathyroidism. The prevalence of the disease varies greatly and the data on the natural history of this disease are sparse and inconclusive.
Objectives
The objectives of this study are to describe the prevalence of NPHPT and its natural history in a referral population and to compare the variability of serum calcium with a group of patients with primary hyperparathyroidism (PHPT).
Design
A retrospective study was conducted over 5 years.
Setting
The setting for this study was a metabolic bone referral center.
Patients
A total of 6280 patients were referred for a bone mineral density measurement (BMD).
Main Outcome Measures
The prevalence and natural history of NPHPT and variability of calcium were the main outcome measures.
Results
We identified NPHPT patients using data from the day of the BMD measurement. We excluded patients with low estimated glomerular filtration rate (eGFR) or vitamin D, or with no measurements available. Based on the evaluation of their medical files, we identified 11 patients with NPHPT (prevalence 0.18%). Only 4 patients had consistent normocalcemia throughout their follow-up, with only 2 also having consistently high PTH. None had consistently normal eGFR or vitamin D.
Intermittent hypercalcemia was present in 7 of the 11 NPHPT patients. The mean adjusted calcium was found to be significantly lower in the NPHPT group compared with the PHPT group but higher than the control group. PTH was similar for NPHPT and PHPT. These 2 groups had similar variability in serum calcium.
Conclusions
NPHPT patients often have episodes of hypercalcemia. We believe that NPHPT is a mild form of PHPT.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © Endocrine Society 2020. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited. |
Keywords: | normocalcemic hyperparathyroidism; prevalence; natural history; epidemiology; primary hyperparathyroidism |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Medicine, Dentistry and Health (Sheffield) > School of Health and Related Research (Sheffield) > ScHARR - Sheffield Centre for Health and Related Research The University of Sheffield > Sheffield Teaching Hospitals |
Funding Information: | Funder Grant number Medical Research Council MR/K006312/1 |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 17 Mar 2020 10:53 |
Last Modified: | 17 Mar 2020 10:53 |
Status: | Published |
Publisher: | The Endocrine Society |
Refereed: | Yes |
Identification Number: | 10.1210/clinem/dgaa084 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:157483 |