Endocrine Abstracts

Background: Primary Hyperparathyroidism (PHPT) is characterized by excess production of parathyroid hormone (PTH) causing hypercalcaemia and reduced bone density. Dual-energy X-ray absorptiometry (DEXA) is the gold standard investigation for assessing bone mineral density (BMD) and diagnosing osteoporosis. Standard DEXA scans typically include hip and lumbar spine while forearm osteoporosis is the hallmark of PHPT-induced bone loss. This study was aimed at evaluating how often DEXA scans included the forearm and whether the forearm scans revealed a high prevalence of osteoporosis as compared to the hip and spine.

Methods: A retrospective review was conducted on patients diagnosed with PHPT over a period of 5 years. DEXA scan results were analyzed based on whether the forearm was included and T scores were compared between the 3 sites.

Results: A total of 347 patients with primary hyperparathyroidism (PHPT) who had undergone DEXA scans were identified. Among them, only 178 (51%) had scans that included the forearm. When defining osteoporosis as a T-score of -2.5 or lower, osteoporosis was detected in 70 patients (39%) in the forearm, while only 26 (14%) had it in the hip, and 18 (10%) in the lumbar spine. The average T-scores were -1.94 in the forearm, -1.34 in the femoral neck, and -0.76 in the lumbar spine. Notably, 22 patients (12.3%) had normal T-scores in the hip and spine but showed osteopenia or osteoporosis in the forearm. Relying solely on two-site DEXA may underestimate the extent of bone disease in patients with PHPT.

Conclusion: This study highlights the importance of including the forearm in DEXA scans in patients with PHPT as recommended by NICE NG132. Routine inclusion of the forearm may result in increased detection of a recognised complication of PHPT, and improved risk stratification with more accurate decision making for definitive management.