OR32-6 Pre-Surgical GH Levels Predict the Risk of Morphometric Vertebral Fracture, Which Is an Early and Frequent Event in the Natural History of Acromegaly

Abstract

Introduction. Acromegalic osteopathy is an emerging complication of the disease, characterized by increased bone turnover, deterioration in bone microarchitecture and high risk of vertebral fractures (VFs). However, the prediction of VFs in this clinical setting is still a matter of uncertainty, since the pathogenesis of acromegalic osteopathy is multifactorial and fractures may occur even in presence of normal bone mineral density. Purpose of the study. We aimed at evaluating the prevalence and determinants of VFs in a cohort of patients (pts) with acromegaly at hospital admission for transsphenoidal (TNS) surgery. Patients & Methods. We retrospectively enrolled 65 pts (34M/31F; age 50.4±11.7yrs) attending the Neurosurgery Unit before TNS surgery. All pts had a confirmed diagnosis of acromegaly (nadir GH during OGTT 75gr > 0.4 ng/mL and IGF-I above age-standardized upper normal limit), in whom all parameters of other pituitary axes (TSH, fT3, fT4, ACTH, cortisol, PRL, LH, FSH, E2/Testosterone) and a thoracic X-ray carried out for anesthesiological reasons were available. We performed a vertebral morphometric evaluation of the thoracic spine on X-ray images (MTRx), according to Genant grading. Data are presented as mean±SD; normally distributed continuous variables were analyzed with Student-t test; categorical data were analyzed with Fisher’s exact test. Results. Medical pre-treatment with SRLs was prescribed in 37 pts (56.9%, 19M/18F). At morphometric evaluation, 21 pts (32.3%, 11M/10F) presented with VFs (14 pts with mild VFs, 7 pts with moderate VFs). The fractured pts showed significantly higher GH levels when compared to non-fractured (20.1±28.0 ng/mL vs. 7.5±7.0 ng/mL; p<0.01). Conversely, no significant differences in thyroid, adrenal and gonadal parameters, as well as IGF-I and PRL levels between the two groups were observed. In multiple logistic regression analysis, GH was independently associated with the risk of any fracture (OR 1.09, 95%CI 1.01-1.17; p=0.03) and severity of VFs (1.04, 95%CI 1.01-1.07; p=0.03). Conclusions. For the first time, we observed that VFs are a very frequent, early and sometimes severe complication of acromegaly. Our findings also showed that pre-surgical GH levels were able to predict the risk and the severity of VFs at MTRx in patients with acromegaly.