SUN-828 - Non-Surgical Management Shows Comparable Bone and Fracture Outcomes to Surgery in Mild Primary Hyperparathyroidism and Osteoporosis: A Retrospective Cohort Study

Primary hyperparathyroidism (PHPT) is associated with reduced bone mineral density (BMD), osteoporosis, and an increased fracture risk. Although parathyroidectomy is the only curative treatment shown to reduce this risk, most older asymptomatic patients are managed nonoperatively, with limited evidence supporting medical therapies beyond oral bisphosphonates. To better characterize BMD and fracture outcomes, we conducted a retrospective analysis comparing 3 real-world management strategies in 92 patients with mild PHPT and osteoporosis.

Methods: Patients were stratified into 3 groups: parathyroidectomy only (n=26), medication only (n=35), or both (n=31). Participants were aged 50-75 with confirmed PHPT, mild hypercalcemia ( < 12 mg/dL) and osteoporosis. Calcium >12 mg/dL, prolonged steroid use, hormone replacement therapy, or other metabolic bone disease were excluded. BMD and T-scores were assessed using DXA at total hip, lumbar spine, femoral neck, and distal 1/3 radius. % change in BMD and T-scores were evaluated at 1, 2, and 5 years post intervention (t1, t2, t5). Kruskal-Wallis and Chi-square tests were used to compare continuous and categorical variable respectively. Among those who received medications, Wilcoxon tests compared continuous variables, while Fisher’s exact and chi-square tests compared categorical variables.

Results: The cohort had a mean age of 62.8 ± 7.2 years and was mostly female (92.4%). Race differed significantly across treatment groups (p=0.019), with a higher proportion of Black in the medication only group (57.1%). Pre-intervention calcium also differed significantly between groups (p=0.003), with higher values observed in patients undergoing parathyroidectomy (10.8 mg/dL ± 0.6). Among patients receiving medications, oral bisphosphonates were the most used, particularly alendronate. Baseline prevalence of osteoporosis and composite high-impact trauma and fragility fractures did not differ between the groups. Overall post-intervention incidence of fragility fractures was 21.7% with the highest incidence in the medication only group (n=9); however, this was not significant (p=0.62).

Baseline BMD and T-scores were comparable across treatment groups. Significant differences were observed in % BMD change at total hip at t2 (p = 0.026) and t5 (p = 0.047), with the medication only group showing an increase (+1.1% ± 7.5 and +3.4% ± 6.9 at t2 and t5, respectively) (mean ± SD). Significant differences were also noted in % BMD change at femoral neck at t2 (p = 0.047), with the least decline following parathyroidectomy (-1.3% ± 8.6) (mean ± SD).

Conclusion: In patients with mild PHPT, parathyroidectomy did not demonstrate superior improvement in BMD compared to medical therapy alone except at the femoral neck. Furthermore, patients treated with medication only showed small but measurable gains in BMD at the hip, while fracture incidence did not differ significantly between groups.

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