Normocalcemic primary hyperparathyroidism in clinical practice: an indolent condition or a silent threat?

Arq Bras Endocrinol Metabol. 2011 Jun;55(5):314-7. doi: 10.1590/s0004-27302011000500003.


Objective: To describe the characteristics of normocalcemic primary hyperparathyroidism (NPHPT) in patients seen for osteoporosis evaluation.

Patients and methods: We examined the records of 156 women who came to the hospital to be screened for osteoporosis. Measurements of total calcium, PTH, 25-hydroxy vitamin D, and β-C-telopeptide were recorded. Bone mineral density and T-scores were evaluated by densitometry of the lumbar spine, femoral neck and distal one-third of the radius. The latter was only measured in patients with primary hyperparathyroidism. Nephrolithiasis and bone fractures were documented by a review of the medical records.

Results: We identified 14 patients with NPHPT, accounting for 8.9% of the population studied. In the medical records, the occurrence of kidney stones was reported in 28.6% of the patients with NPHPT, in contrast with only 0.7% of the noncarriers. Regarding the presence of general fractures, 21.4% of the patients with NPHPT were affected versus 16.2% of noncarriers.

Conclusion: Data from our study suggest that NPHPT has a diverse phenotypic presentation, implying that this may not be an "indolent" disease.

MeSH terms

  • Adult
  • Biomarkers
  • Bone Density / physiology*
  • Brazil / epidemiology
  • Calcium / blood*
  • Collagen Type I / blood
  • Female
  • Fractures, Bone / diagnosis
  • Fractures, Bone / epidemiology
  • Humans
  • Hyperparathyroidism, Primary / blood*
  • Hyperparathyroidism, Primary / epidemiology
  • Kidney Calculi / diagnosis
  • Kidney Calculi / epidemiology
  • Middle Aged
  • Osteoporosis / diagnosis*
  • Osteoporosis / epidemiology
  • Parathyroid Hormone / blood*
  • Peptides / blood
  • Vitamin D / analogs & derivatives
  • Vitamin D / blood


  • Biomarkers
  • Collagen Type I
  • Parathyroid Hormone
  • Peptides
  • collagen type I trimeric cross-linked peptide
  • Vitamin D
  • 25-hydroxyvitamin D
  • Calcium