Endocrine Abstracts

JOINT1890

Background: Primary hyperparathyroidism (PHPT) is a common endocrine disorder characterized by excessive parathyroid hormone (PTH) secretion, disrupting calcium and phosphorus metabolism. Among its systemic effects, bone health is particularly affected due to reduced bone mineral density (BMD) and an increased risk of skeletal fragility and fractures.

Objectives: 1) To compare BMD and fracture risk (using the FRAX calculator) between PHPT patients and controls. 2) To analyze T and Z scores at different skeletal sites: spine, proximal femur, and distal one-third of the radius.

Methods: The study included PHPT patients diagnosed at the University Clinical Center’s Endocrinology and Internal Medicine Department (2014–2024) who underwent densitometry using a Hologic device. The control group consisted of patients from the same period who also underwent densitometry but were not diagnosed with PHPT. Exclusion criteria included chronic kidney disease, antiresorptive or glucocorticoid therapy, rheumatoid arthritis, congenital bone fragility, diabetes mellitus type 1, hypogonadism, premature ovarian failure, malabsorption syndrome, and chronic liver disease.

Results: Among 441 patients evaluated for hypercalcemia, 237 met the inclusion criteria: 191 with PHPT and 46 controls. The study and control groups were matched for age, gender, and BMI. No significant differences in BMD were found between the PHPT and control groups in women (P = 0.13) or men (P = 0.26). Similarly, major osteoporotic and hip fracture risks did not significantly differ (P = 0.28 and P = 0.19, respectively). Notably, in the PHPT group, T-scores differed significantly among the lumbar spine, femoral neck, and radius (P< 0.01), while Z-scores did not (radius vs. femur: P = 0.665; radius vs. lumbar: P = 0.14). In the control group, no significant differences were observed in either T-scores (P = 0.556) or Z-scores (P=0.384).

Conclusions: Consistent with prior research, our findings confirm a preferential loss of cortical bone in PHPT patients. However, femoral neck BMD and fracture risk were not significantly higher compared to controls.