Normocalcemic and Normohormonal Primary Hyperparathyroidism: Laboratory Values and End-Organ Effects

Otolaryngol Head Neck Surg. 2021 Sep;165(3):387-397. doi: 10.1177/0194599820983728. Epub 2021 Jan 19.


Objective: Variants of primary hyperparathyroidism (pHPT), described as normocalcemic (NC) and normohormonal (NH), can confuse the diagnosis of classic pHPT.

Data sources: A MEDLINE search was performed for variants of pHPT using the PubMed database (last queried October 2019).

Review methods: The search was restricted to articles published after 1960 that were specific to humans. Studies were included in our analysis if laboratory values and incidence of end-organ involvement were reported for NCpHPT and NHpHPT variants. The search returned 189 articles; 27 additional studies were identified and included for a total of 216. Non-English-language studies were excluded. Abstracts were screened, full-text articles were then assessed, and 82 articles were excluded. Data were pooled using a random-effects model in studies that compared NC or NH pHPT to classic pHPT. Comparative laboratory values are presented.

Conclusion: This analysis compares NCpHPT and NHpHPT to classic pHPT. Nephrolithiasis was 21.7% (NCpHPT), 15.9% (classic pHPT), and 25.4% (NHpHPT). Decreased bone mineral density was 49.7% (NCpHPT), 39.7% (classic pHPT), and 40.3% (NHpHPT). Fractures in the NCpHPT group were not significantly different from the classic pHPT. Hypertension in the NCpHPT group was significantly less than classic pHPT (odds ratio, 0.59; 95% CI, 0.40-0.88).

Implications for clinical practice: This information may serve to inform clinicians of the laboratory subtleties of these variants that are being seen with greater frequency in contemporary practice.

Keywords: asymptomatic; borderline; calcium; complications; end organ effects; laboratory values; normocalcemic; normohormonal; parathyroid hormone; primary hyperparathyroidism.

Publication types

  • Review

MeSH terms

  • Biomarkers / blood
  • Bone Density
  • Calcium / blood*
  • Fractures, Bone / etiology
  • Humans
  • Hyperparathyroidism, Primary / classification*
  • Hypertension / etiology
  • Parathyroid Hormone / blood*


  • Biomarkers
  • Parathyroid Hormone
  • Calcium