Spine Bone Texture Assessed by Trabecular Bone Score in Active and Controlled Acromegaly: A Prospective Study

Abstract

Purpose Acromegalic patients have an increased vertebral fracture (VFx) risk due to bone quality reduction, independently of bone mineral density (BMD). Aim of the study is to describe bone quality in acromegaly, measured by Trabecular bone score (TBS), a non-invasive index for assessing bone microarchitecture. Methods We collected data of 18 patients (13 F, age 56.2±15 years) newly diagnosed with acromegaly. Thirty-six age-and gender matched healthy controls were also recruited. Pituitary function, bone and calcium-phosphorous metabolism, and BMD at spine and femur and TBS (by dual-X-ray absorptiometry) were assessed in acromegalic patients at diagnosis and 12 months after the achievement of IGF-1 normalization. Results At diagnosis, BMD and the VFx prevalence were comparable between patients and controls (28.3 ± 5.9 vs 27.6 ± 3.7 and 11% vs 8.3%), while TBS was significantly lower in acromegalic patients (1.20±0.13 vs 1.30±0.06; p<0.001) and CTX and osteocalcin were significantly higher compared to controls (707±365.7 vs 371±104.1 pg/ml; p=0.001 and 31.6 ± 15.4 vs 17.0 ± 5.7 ng/ml; p=0.001 respectively). One year after IGF-1 normalization, a significant reduction of bone turnover indexes in the group of acromegalic patients surgically cured (osteocalcin decreased of 61.2%, CTX decreased of 60.3%) compared to the ones controlled by medical therapy was observed (osteocalcin decreased of 39%, CTX decreased of 40.7%; p= 0.01 and p=0.001, respectively). Despite these findings, no TBS or BMD variations were observed. Conclusions Acromegalic patients have an impaired bone quality despite normal density. Achieving normal GH secretion rapidly leads to the normalization of bone turnover.

Trabecular Bone Score and Osteoprotegerin as Useful Tools in the Assessment of Bone Deterioration in Acromegaly

“…They observed the decrease of TBS and the increase of BMD following the treatment ( 13 ). On the contrary, in the recent study, no TBS and BMD variation was observed 1 year after the biochemical cure or control of the acromegaly disease ( 30 ).…”

“…We did not observe the correlation between TBS as well as BMD and bone markers (NTX and OC concentrations). In some previous studies, an increase of bone turnover markers (OC and CTX-1) in AGs compared to controls ( 10 , 30 ) or CA ( 39 ) was demonstrated, but they also did not find the correlation between these markers and BMD ( 10 ). Moreover, taking into account the fact that only 15% of OC is detected in the circulation, and that the characteristic feature of this non-collagenic protein is the high concentration variation in the circadian secretion profile (up to 30%) ( 40 ), this could have influenced the results obtained in our study and, as a result, the lack of significant differences in the concentration of OC between the groups.…”

“…Similarly, Sala et al. showed that patients with AA had a significantly lower TBS compared to control, regardless of age, sex, BMI, and gonadal status ( 30 ). Correspondingly, Calatayud et al.…”

Trabecular Bone Score as a Reliable Measure of Lumbar Spine Bone Microarchitecture in Acromegalic Patients

“…Indeed, Calatayud and colleagues reported higher TBS values in patients who underwent post-surgical remission [ 43 ], while a previous report from Godang K et al described a reduction in TBS values one year after surgery, although associated with an increase in BMD levels [ 24 ]. Recently, Sala and colleagues failed to demonstrate significant changes in both TBS and BMD values in a prospective study evaluating 18 acromegalic patients at diagnosis and 12 months after achieving cured/controlled disease (66.7% of the patients were treated with somatostatin receptor ligands) [ 44 ].…”

“…Currently, few studies have analyzed TBS in patients with acromegaly [ 23 , 24 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 ]. In most cases, the authors reported lower TBS values in acromegalic patients compared to healthy subjects.…”