Clinical, Biochemical, and Radiological Profile of Normocalcemic Primary Hyperparathyroidism

• Published in: The journal of clinical endocrinology and metabolism Vol. 105; no. 7; pp. e2609 - e2616
• Main Authors: Palermo, Andrea, Naciu, Anda Mihaela, Tabacco, Gaia, Falcone, Stefania, Santonati, Assunta, Maggi, Daria, D’Onofrio, Luca, Briganti, Silvia Irina, Castellitto, Domenico, Casini, Alessandro, Pedone, Claudio, Lelli, Diana, Fabbri, Andrea, Bilezikian, John P, Napoli, Nicola, Pozzilli, Paolo, Manfrini, Silvia, Cesareo, Roberto
• Format: Journal Article
• Language: English
• Published: US Oxford University Press 01.07.2020; Copyright Oxford University Press
• Subjects: Absorptiometry, Photon; Aged; Biomarkers - blood; Bone Density - physiology; Calcium - blood; Cross-Sectional Studies; Female; Femur Neck - diagnostic imaging; Humans; Hyperparathyroidism, Primary - blood; Hyperparathyroidism, Primary - diagnostic imaging; Lumbar Vertebrae - diagnostic imaging; Male; Middle Aged; Parathyroid Hormone - blood; Vitamin D - analogs & derivatives; Vitamin D - blood; hypercalcemia; normocalcemic; calcium; PTH; Hyperparathyroidism
• ISSN: 0021-972X; 1945-7197; 1945-7197
• DOI: 10.1210/clinem/dgaa174

Abstract Context The clinical and radiological aspects of normocalcemic hyperparathyroidism (NHPT) are confounded by the differing methods used to rule out secondary hyperparathyroidism and by the small sample size. Objective To assess the clinical, biochemical, and radiological profile of NHPT compared with primary hyperparathyroidism (PHPT) and control subjects Design Multicentric cross-sectional study Setting Outpatient clinic Patients 47 NHPT, 41 PHPT, and 39 age- and sex-matched control subjects. Main Outcome Measures Calcium metabolism and bone turnover markers (BTMs). Lumbar spine, total hip, femoral neck, one-third distal radius bone mineral density (BMD). Morphometric vertebral fracture (VF) assessed by dual-energy X-ray absorptiometry. Results NHPT patients had significantly higher parathyroid hormone, 25(OH)-vitamin D levels and lower calcium × phosphorus product than controls (P < .001). Compared with PHPT, the NHPT group had significantly higher 25(OH) vitamin D levels (P = .016). NHPT had BTM levels similar to controls and PHPT. NHPT, PHPT, and controls have similar lumbar spine and femoral neck BMD. NHPT and controls had a similar radial BMD, while patients with PHPT had a lower radial BMD than both patients with NHPT (P = .031) and controls (P < .05). Using the control group as the reference, after adjustment for interacting factors, there was no increase in risk of moderate–severe VF in NHPT (odds ratio [OR] 1.04, 95% confidence interval [CI] 0.25-4.55), while PHPT had an increased risk (OR 3.81,95% CI 1.15-15.12). Seventy-nine percent of NHPT and 59% of PHPT patients fulfilled the criteria for asymptomatic hyperparathyroidism. Conclusions The biochemical phenotype of NHPT is intermediate between PHPT and controls. In contrast, the bone phenotype resembles controls with normal bone turnover, no significant BMD impairment, and no increased risk of VF.