Bone-modifying agents may alter biochemical presentation and operative findings in primary hyperparathyroidism.

BACKGROUND: Primary hyperparathyroidism is closely linked to bone metabolism, leading to increased bone resorption and osteoporosis. Bone-modifying agents are commonly used to mitigate bone loss by altering calcium metabolism; however, their effect on the biochemical and operative presentation of primary hyperparathyroidism has not been well characterized. This study evaluates the association between bone-modifying agent use, biochemical markers, and operative findings among patients with primary hyperparathyroidism. METHODS: A retrospective review was conducted of patients who underwent parathyroidectomy for primary hyperparathyroidism between 2019 and 2025 at a single tertiary referral center. A history of bone-modifying agent use and bone disease was assessed. Descriptive statistics and univariate analyses were performed to evaluate associations between bone-modifying agent use and the biochemical and operative phenotypes of primary hyperparathyroidism. RESULTS: A total of 899 patients met inclusion criteria, of whom 187 (20.8%) had a history of bone-modifying agent use. Patients with bone-modifying agent use were more likely to be female (P < .001), White (P < .001), and older on average (70 vs 60 years, P < .001). Mean serum calcium levels (10.5 vs 10.9 mg/dL, P < .001) and mean parathyroid hormone levels (99.5 vs 119.7 pg/mL, P < .001) were lower among bone-modifying agent users. Multigland disease was more frequent in bone-modifying agent users (43% vs 32%, P = .03) as was bilateral neck exploration (54% vs 45%, P = .033). CONCLUSION: In patients undergoing parathyroidectomy for primary hyperparathyroidism, the use of bone-modifying agents is associated with a distinct biochemical profile and a higher prevalence of multigland disease. A more nuanced understanding of the relationship between bone-modifying agents and the pathophysiology and surgical presentation of primary hyperparathyroidism could inform preoperative planning and guide individualized evaluation strategies in this patient population.