Determinants of skeletal fragility in acromegaly: a systematic review and meta-analysis

Trabecular Bone Score as an Index of Bone Fragility in Patients with Acromegaly: A Systematic Review and Meta-Analysis

“…Within the setting of acromegaly, our meta-analysis highlighted the presence of lower TBS values in affected patients compared to unaffected controls. On the contrary, in the same studies, no overall differences in BMD values could be found between the two groups at any skeletal site; this latter outcome is in line with previous literature [5, 21], in which BMD was already shown to be either unaffected (at lumbar spine) or even slightly increased (at femoral neck and total hip) in acromegalic patients with respect to non-acromegalic controls. From a pathophysiological point of view, the finding of lower TBS values in acromegalic patients is coherent with the available data about the impairment in trabecular bone micro-architecture that is typical of acromegalic osteopathy: histomorphometric analyses, in fact, demonstrated a reduced trabecular bone volume, increased trabecular separation, and impaired trabecular biomechanical competence in acromegalic patients compared to controls [46, 47]; moreover, a reduced trabecular bone density and trabecular thickness were also displayed at high-resolution peripheral quantitative computed tomography (HR-pQCT), both at the distal radius and at the distal tibia [48, 49].…”

“…A previous meta-analysis [21], which included articles published until September 2020, did not find any significant differences in TBS between acromegalic patients and controls; however, this result was limited by the low number of available studies; moreover, no data assessing the relationship between TBS and fragility fractures have been presented by the authors, as only one study evaluating this outcome was available at that time [18]. Within the last 2 years, additional research has been published in this regard, both about the difference in TBS between patients with and without acromegaly [13,[15][16][17] and about the comparison of TBS values between acromegalic patients with and without prevalent fragility fractures [13].…”

Endocortical Trabecularization in Acromegaly: The Cause for the Paradoxically Increased Vertebral Fracture Risk?

“…The normalization of bone turnover reduces the bone remodeling space, thereby increasing BMD (23,36,37) and potentially improving fracture risk. (14) TBS is a DXA-derived estimate of the microstructure of the trabeculae in vertebral bodies and, thus, complementary to BMD. (21,22) At baseline, TBS was reduced compared to normative data, but should be interpreted with caution as data were only available for about two thirds of the population due to software limitations.…”

“…Vertebral fractures are frequently silent and demonstrated by chance or during systematic studies. As outlined, the prevalence of incident fractures increases in patients with acromegaly or with a history of previous active acromegaly, ( 7,10–12,14,31–33 ) despite an increase in the bone area of vertebral bodies. The overall bone fragility is potentially related to microstructure alterations in trabecular thickness, trabecular separation, and cortical bone porosity.…”

“…(13) Another recent meta-analysis confirmed that the risk for vertebral fractures was sevenfold elevated in patients with acromegaly compared to controls. (14) Taken together, patients with acromegaly possess an increased fracture risk, especially in trabecular bone, despite an increase in overall bone size and potentially enlarged cortical thickness, and thereby an improved moment of inertia. (15) The effects of active acromegaly on the different compartments and envelopes of bone at the organ level are scarcely studied.…”