AB0882 ACROMEGALY DO NOT INCREASE THE RISK OF VERTEBRAL FRACTURES : A RETROSPECTIVE AND PROSPECTIVE STUDY ON 50 PATIENTS

Abstract

Background Patients with acromegaly appear to be at an increased risk of vertebral fractures (VFs) despite normal bone mineral density (BMD)1. However, these patients could have several endocrine deficits as hypogonadism known to increase the fracture risk risk independently of the GH effects. The physiopathology of GH excess on bone is unclear. In addirion, patients with acromegaly have radiological deformations of the spine, called Erdheim’s syndrome, which can overestimate the radiological vertebral fractures. Objectives Investigate the prevalence of VFs in our cohort of patients with acromegaly. Methods It was a monocentric, retrospective and prospective study. The rheumatologic evaluation was less than 3 years for all patients. For 40% of patients, this evaluation was prospective after the begin of the sudy. Acromegaly patients younger than 80 and followed at the Nantes University hospital in January 2018 were included. Patients were excluded if they had a rheumatologic or endocrinologic disease interfering with the results. The prevalence of radiological vertebral fractures was evaluated on conventional lombar and thoracic spine radiographs using Genant’s semi-quantitative assessment. We also assessed qualitative abnormalities of the spine using 3 criteria : osteophytes, disc space narrowing and cuneiform aspect of vertebrae. The X-rays were read by two rheumatologists independently. We analyzed BMD at lumbar spine and total hip, endocrine status and quality of life through 3 questionnaires (AcroQol, specific of acromegaly; Oswestry evaluating the functional impact of pain; HAQ evaluating the functional capacity). Results We included 56 patients. 6 patients were excluded : 3 declined, 1 had bone metastasis and 2 had another endocrinologic disease (adrenocortical and panhypopituitarism). We analyzed the prevalence of VFs in 50 patients (19 females, 31 males, median age 53, range 28-79). The average of time between the diagnosis of acromegaly and the last rheumatologic evaluation was 9.1 years. 3 patients (6.1%) had a VF : 1 grade 1 and 2 grade 2 of Genant’s assessment. 28% patients were osteopenic and 12% were osteoporotic. Among fractured patients, 2 were osteoporotic and 1 osteopenic. 26% were hypogonadal (100% substituted), 16% had central adrenal insufficiency (100% substituted). 14 women were menopaused (74% of women). Thoracic spine was deformed in 31 patients (61%) and lombar spine in 21 patients (43%), for at leat one of the 3 criteria. Patients with spine deformation were older (p=0.043), with higher BMI (p=0.004) and had a trend to be more hypogonadal (p=0.06). Concerning quality of life, AcroQoL’s average was 70.9% (score 0 to 100, maximal quality of life =100, range 32-98), HAQ’s average was 0.18 (score 0 to 3, maximal quality of life 0, range 0-1.38) and Oswestry’s average was 9.8 (score 0 to 100, maximal quality of life 0, range 0-44). Conclusion This study shows fort the first time that acromegaly patients are not at an increased risk of vertebral fractures. This result differs from the literature that reported more than 30% of VF in this population. Our study bring several points of explanation. First, the vertebral abnormalities were frequent in our patients and can overestimate the VFs without a qualitative analysis of the X-ray. Secondly, the right endocrine balance plays an important role in osteoporosis. Our patients were well supplemented, it can reduce the risk of osteoporosis. More studies are needed to confirm this new hypothesis. Reference [1] Claessen and al. 2016. « Bone and Joint Disorders in Acromegaly ». Neuroendocrinology 103 (1):86–95. Disclosure of Interests charlotte plard: None declared, Clarisse Hochman: None declared, Delphine Drui: None declared, Bertrand Cariou: None declared, Yves Maugars: None declared, Benoit Le Goff Speakers bureau: Abbvie, BMS, Janssen, MSD, Pfizer, Sanofi-Genzyme, UCB, Novartis, pascale Guillot: None declared