Endocrine Abstracts

Acromegaly is a rare disease, caused by an excessive secretion of growth hormone (GH), and consequently the insulin like growth factor 1 (IGF-1). Patients with acromegaly have an increased risk of fractures, which might be correlated with insufficient quality of bone. It is known that use of FRAX in acromegaly is not validated, however we do not have other useful tools to assess real risk for fractures. The new valuable tool in the assessment of bone structure is the trabecular bone score (TBS) measurement, which provides some information on bone microarchitecture from a routine DXA. The high TBS score reflects better bone structure, whereas a low TBS score indicates impaired bone structure associated with higher fracture risk.

Purpose: The aim of this study was to assess the usefulness of TBS in prediction of fractures in patients with acromegaly.

Materials and methods: We studied 63 patients with acromegaly and 42 healthy controls (CG). Acromegaly patients were divided into three subgroups on the basis of disease activity (AA – active acromegaly, CTA – controlled treatment acromegaly (during somatostatin analogues therapy) and CA – cured acromegaly). In all patients blood samples were obtained to assess the hormonal and metabolic status. The bone mineral density (BMD) of the lumbar spine (LS) (L1-L4), femoral neck (FN) was measured using the dual-energy X-ray absorptiometry (DXA) method by densitometer. All TBS values were analyzed using the TBS iNsight software, (Med-Imaps, Pessac, France) using spine DXA files from the database.

Results: Lumbar spine TBS was significantly lower in the whole acromegaly group (AA + CTA + CA) vs CG (1.22 ± 0.13 vs 1.29 ± 0.10, P = 0.019). In contrast, BMD at all sites did not differ between these groups. Additionally, TBS was significantly higher in CG compared to CTA (1.29 ± 0.10 vs 1.18 ± 0.12, P = 0.00) as well as to CTA + CA (1.29 ± 0.10 vs 1.21 ± 0.14, P = 0.00). Similarly, BMD also did not differ among these groups. The risk of major fractures and hip fractures was significantly higher in the whole acromegaly group as well as in CTA + CA and in CTA compared to CG (P = 0.00 for all).

Conclusions: The present results confirmed the higher risk of fractures in acromegaly patients despite of BMD results. Low TBS score reflects worse bone structure in acromegaly. TBS may be a useful tool for predicting risk of fractures in acromegaly patients.