Evaluation of bone density and microstructure by DXA, TBS and HR-pQCT: an assessment of cortical porosity and its association with vertebral fractures in patients with acromegaly.

Purpose: Patients with acromegaly are at increased risk of fractures, regardless of areal bone mineral density (BMD). This study aimed to identify whether vertebral fractures (VFs) are related to decreases in bone volumetric density and microstructure via high-resolution peripheral quantitative computed tomography (HR-pQCT) and the trabecular bone score (TBS).

Methods: VF was evaluated in 49 patients with acromegaly (22 men and 27 women) via spine X-ray. Areal BMD, volumetric BMD, and bone microstructure were analyzed via dual-energy X-ray absorptiometry (DXA) and HR-pQCT. Lumbar spine trabecular quality was assessed via TBS.

Results: Morphometric VFs were identified in 22 patients (11 men and 11 women), accounting for 44.9% of the cohort. Hypogonadism was more common in patients with VFs (59.1% vs. 22.2%; p = 0.017). BMD measured by DXA or HR-pQCT did not differ between patients with and without VFs. The proportion of patients classified as having partially degraded or degraded bone microstructure according to a TBS < 1.310 was 26% (with VF) vs. 32% (without VF; p = 0.749). There was no difference in bone geometry (trabecular and cortical area, cortical perimeter) or microstructure (number, thickness, separation, and trabecular heterogeneity, as well as cortical thickness), except for a trend toward greater cortical porosity at the distal radius in patients with VFs (p = 0.067).

Conclusions: VFs were identified in 44.9% of patients with acromegaly, and hypogonadism was more common among those with VFs. There were no significant differences in bone density or microstructure measured by DXA, TBS, or HR-pQCT in patients with or without VFs.