Vertebral Fractures Occur Despite Control of Acromegaly and Are Predicted by Cortical Volumetric Bone Mineral Density

Context: Recent studies suggest that cortical bone could also play a role in vertebral fracture (VF) development in acromegaly. Objective: Evaluate the occurrence of VFs and their relationship to dual energy x-ray absorptiometry-derived bone parameters. Methods: A single-center 2-year prospective study of acromegaly patients was conducted. Each subject had L1-4 spine, femoral neck and total hip (TH) areal BMD measured using DXA, and trabecular bone score (TBS) measurement performed. 3D ShaperT was used to assess proximal femur trabecular and cortical volumetric (v)BMD, cortical surface (s) BMD, and cortical thickness (Cth). VF assessment was performed using the lateral spine imaging IVAT mode with a Hologic Horizon (R) densitometer using a semiquantitative approach. Study outcomes were assessed at 2 time points: baseline and month 24. Results: 70 acromegaly patients (34 M/36F; average 55.1 years) were studied, including 26 with active disease. In 13 patients, 9 with controlled disease, VF was observed. A decrease in TBS, sBMD, neck trabecular vBMD, TH, and neck cortical vBMD in VF compared with non-VF subjects was observed (P <.05). Multivariate analysis of fracture prediction showed TH cortical vBMD as the best fracture prediction parameter with area under the curve of 0.774. TBS was negatively associated with fasting plasma glucose and glycated hemoglobin (HBA1c) at each time point during the follow-up. Conclusion: From the total number of 13 VF subjects, 9 were in the controlled disease group. The most sensitive and specific predictor of incident VF was TH cortical vBMD, suggesting that cortical bone is involved in fracture development.