Spine bone texture assessed by trabecular bone score in active and controlled acromegaly: a prospective study

Context: Acromegalic patients have an increased vertebral fracture (VFx) risk due to bone quality reduction, independently of bone mineral density (BMD). Objective: The aim of the study is to describe bone quality in acromegaly, measured by trabecular bone score (TBS), a noninvasive index for assessing bone microarchitecture. Methods: We collected data from 18 patients (13 female, age 56.2 ± 15 years) newly diagnosed with acromegaly. Thirty-six age- and sex-matched healthy controls were also recruited. Pituitary function, bone and calcium-phosphorous metabolism, and BMD at spine and femur and TBS (by dual-energy x-ray absorptiometry) were assessed in acromegalic patients at diagnosis and 12 months after the achievement of insulin-like growth factor 1 (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%), whereas TBS was significantly lower in acromegalic patients (1.20 ± 0.13 vs 1.30 ± 0.06; P < .001) and carboxyterminal telopeptide (CTX) and osteocalcin were significantly higher compared to controls (707 ± 365.7 vs 371 ± 104.1 pg/mL; P = .001 and 31.6 ± 15.4 vs 17.0 ± 5.7 ng/mL; P = .001, respectively). One year after IGF-1 normalization, a significant reduction of bone turnover indexes was observed in the group of acromegalic patients surgically cured (osteocalcin decrease of 61.2%, CTX decrease of 60.3%) compared to the ones controlled by medical therapy (osteocalcin decrease of 39%, CTX decrease of 40.7%; P = .01 and P = .001, respectively). Despite these findings, no TBS or BMD variations were observed. Conclusion: Acromegalic patients have impaired bone quality despite normal density. Achieving normal growth hormone secretion rapidly leads to the normalization of bone turnover.