Endocrine Abstracts

Introduction: Acromegalic bone disease is characterized by an increased prevalence of fragility vertebral fractures (VFs). However, an effective, non-invasive and cost-efficient imaging technique that can diagnose early bone alterations in this category of patients is yet to found. The use of bone mineral density (BMD) is not as useful as in other causes of osteoporosis as excess GH leads to specific microarchitectural alteration of trabecular bone, which don’t translate to an important decrease in BMD. Trabecular bone score (TBS) is a more novel technique proposed for use in these patients.

Methods: We performed a cross-sectional study on 71 acromegalic patients, with either controlled, cured or uncontrolled disease. The turnover markers evaluated for both groups were alkaline phosphatase, osteocalcin, the C-terminal telopeptide of type I collagen and total procollagen type 1 amino-terminal propeptide (P1NP) and the imaging techniques performed were dual x-ray absorptiometry to evaluate BMD, T and Z scores of the lumbar spine (LS), femoral neck (FN) and total hip (TH), TBS and x-ray scans of the thoracic and lumbar spine.

Results: The patients had a prevalence of moderate of severe VFs of 29.6%, mild fractured not having been taken into consideration. Acromegaly subjects with and without hypogonadism had no significant differences in terms of BMD (LS: 1.07±0.176 vs. 1.129±0.23 g/cm2, P=0.229, FN: 0.999±0.151 vs. 0.954±0.124 g/cm2, P=0.198, TH: 1.03±0.148 vs. 0.996±0.148 g/cm2, P=0.349), TBS (1.182±0.148 vs. 1.141±0.183, P=0.308), or VFs prevalence (31.81% vs. 25.92%, P=0.597). Acromegaly patients with VFs had significantly lower osteocalcin and P1NP levels than those without VFs, as well as lower BMD at all skeletal sites (LS: 1.015±0.18 vs. 1.124±0.199 g/cm2, P=0.034; FN: 0.904±0.117 vs. 1.015±0.14 g/cm2, P=0.002; TH: 0.933±0.13 vs. 1.052±0.141 g/cm2, P=0.001). Nonetheless, TBS did not present significant differences in fractured compared to non-fractured patients (1.131±0.171 vs. 1.181±0.158, P=0.238). Furthermore, males and females with acromegaly did not have statistically significant differences in BMD, TBS of VFs frequency. Also, disease activity did not influence BMD, TBS or VFs prevalence.

Conclusions: According to our results, vertebral fractures are frequent in acromegaly, with a prevalence of around 30%, and are associated with lower BMD but not with TBS. Moreover, the presence of hypogonadism does not influence BMD, TBS or VFs prevalence in these patients and neither do gender or disease activity.