Assessment of Trabecular Bone Score: a 7-year follow-up study in institutionalized adults with refractory epilepsy and intellectual disability.

Purpose: The aim of this longitudinal study was to assess trabecular bone scores (TBS) in institutionalized adults with refractory epilepsy and intellectual disability and to study the association of TBS and incident fractures during seven years of follow-up.

Methods: In 2009 and 2016, all institutionalized adult patients of a long-stay care facility in the Netherlands (n=261) were invited to undergo a dual-energy X-ray absorptiometry (DXA) including vertebral fracture assessment (VFA) and assessment of TBS. Vertebrae T4-L4 were analyzed using quantitative morphometry. New and worsening vertebral fractures (VFs) were considered as incident VFs. Data regarding clinical fractures were extracted from the medical files. Patients were treated with anti-osteoporosis medication according to the Dutch guideline.

Results: Baseline and follow-up DXA, VFA and TBS could be obtained in 136 patients (83 male) aged between 18 and 79 years old (44.7±15.5). At baseline, 36 patients (26.5%) were diagnosed with osteoporosis, 68 (50.0%) with osteopenia and 32 patients (23.5%) had a normal bone mineral density (BMD). As for TBS, 26 patients (19.1%) had a partially degraded microarchitecture and 26 patients (19.1%) a degraded microarchitecture. During seven years of follow-up, 80 patients (59%) sustained at least one fracture, of which 28 patients (35%) had one or more major osteoporotic fractures. Thirty-four patients (25.0%) had at least one new or worsening morphometric VF. Compared to baseline, TBS significantly decreased over seven years of follow-up in non-treated patients (-0.039±0.064, p<.001). In patients who were treated with bisphosphonates for more than one year during follow-up, TBS did not change significantly (p=.093). In multivariate analyses, no significant associations were found between TBS at baseline and incident fractures during follow-up.

Conclusion: In this study, we found a high incidence of fractures and TBS decreased significantly over seven years of follow-up in non-treated institutionalized adult patients with refractory epilepsy and intellectual disability, but TBS was not associated with incident fractures.