Endocrine Abstracts

Introduction: Patients with acromegaly have an increased fracture risk, particularly vertebral fractures. Growth hormone (GH) excess, and the related increase of IGF-1 levels, have been shown to impair bone microarchitecture more than bone density. Therefore, the assessment of trabecular bone score (TBS) has been recommended beside standard dual-energy X-ray absorptiometry (DXA). The calcaneal quantitative ultrasound (QUS) is less expensive and more accessible compared to DXA, and has been studied in multiple setting as a screening tool for bone status. The aim of this study was to investigate the ability of calcaneal QUS to screen for bone impairment in patients with acromegaly.

Material and Methods: Bone Mineral Density (BMD, g/cm²), lumbar spine T-score (L1-L4), total hip, femoral neck as well as relative skeletal muscle mass index (RSMI) in whole body composition were calculated using a DXA scan [Lunar full-Prodigy (GE Lunar, Madison, WI, USA). Trabecular bone score (TBS) [TBS Insight Medipas Group v 3.0] was derived for each spine DXA examination. Calcaneal QUS (Osteosys BeeTLe, Caresmed) was analyzed and the relative T-score calculated. Fracture Risk Assessment Tool (FRAX), both conventional and modified by TBS, was calculated for each patient. Patient clinical data, including disease control and bone turnover markers, were collected.

Results: Thirty-two patients with acromegaly (44% females), with mean age 59±11 years, were included in the study. Median age-adjusted IGF-1 × upper limit of normality (×ULN) was 0.84 (IQR 0.36-1.32), with the majority of patients (68.8%) having a controlled disease (IGF-1 ≤ 1×ULN). QUS T-score showed a strong positive correlation with DXA T-scores at all sites (rho 0.608-0.795, P<0.001), and a moderate correlation with TBS (rho 0.356, P=0.04). The ROC curve analysis showed that the QUS T-score was able to predict the presence of osteopenia with high sensibility (AUC=0.810, P<0.02). Consistently, a negative correlation was observed between QUS T-score and the FRAX computed for both major osteoporotic fractures and hip fractures (rho= - 0.664 and -0.662, respectively, P< 0.001). Similarly, QUS T-score showed a negative correlation with the FRAX modified by TBS (rho= -0.686 and -0.700, respectively, P< 0.001). Interestingly, QUS T-score showed a positive correlation with RSMI (rho 0.421, P=0.016).

Conclusion: Calcaneal QUS could be a useful tool to screen patients with acromegaly for the presence of osteopenia and fracture risk, selecting patients for DXA evaluation. Moreover, low QUS T-score is also associated with an impairment of bone microarchitecture and the presence of sarcopenia.