Related Experiment Video
Updated: Feb 3, 2026

Split-and-pool Synthesis and Characterization of Peptide Tertiary Amide Library
Published on: June 20, 2014
Normocalcemic Primary Hyperparathyroidism: A Comparison with the Hypercalcemic Form in a Tertiary Referral Population
Jan Pierreux1, Bert Bravenboer1
1Universitair Ziekenhuis Brussel, Endocrinology, Brussel, Belgium.
Abstract:
Normocalcemic primary hyperparathyroidism (NPHPT) is a formally recognized variant of primary hyperparathyroidism (PHPT), characterized by normal total and ionized serum calcium concentrations and elevated parathyroid hormone (PTH) levels, in the absence of secondary causes for hyperparathyroidism. NPHPT has been studied previously, but data are limited and confounded. We aimed to compare the clinical and biochemical data of normocalcemic and hypercalcemic subjects in a hospital-based population.We retrospectively analysed the medical records of 131 subjects diagnosed with PHPT at the university hospital Brussels (UZ Brussel) between January 1st 2007 and December 31st 2016, including 25 normocalcemic and 106 hypercalcemic subjects.The mean values of age, BMI, sex, serum 25-OH vitamin D levels and urinary phosphate excretion were comparable between both groups. Subjects diagnosed with NPHPT had significantly lower plasma PTH levels, lower urinary calcium excretion and lower serum creatinine levels compared to the hypercalcemic subjects with PHPT. Corresponding eGFR values were higher in the normocalcemic group. Normocalcemic subjects (NPHPT) presented with a high prevalence of nephrolithiasis (36%), fragility fractures (12%) and osteoporosis (25%). Clinical manifestations and BMD measurements revealed no statistically significant differences between both groups.Our data show a relative prevalence of 19% NPHPT in PHPT. NPHPT may present the earliest form of PHPT with an extension in time, but is not an indolent disease state. Normocalcemic subjects should be managed as hypercalcemic subjects with PHPT. Further research regarding the pathophysiology and natural course of NPHPT is required.
More Related Videos
Related Concept Videos
Tertiary Healthcare System
Nomenclature of Secondary and Tertiary Amines
Conservation of Small Populations
What is Population Genetics?
Population Growth
The Sense of Self: Reflected Self-Appraisal and Social Comparison

