Endocrine Abstracts

Skeleton is an emerging target for systemic complications in acromegaly. The GH/IGF-1 excess is believed to cause an increased bone turnover and negative calcium balance. Observations on bone mineral density (BMD) in acromegalic patients are inconsistent, possibly in relation to skeletal site and method of BMD measurement or gonadal status. Reports on skeletal fragility are also conflicting but it is predominantly believed that an increase of vertebral fractures (VFs) risk is present in acromegaly. This results from deterioration of structural and biomechanical properties of bone, despite preserved BMD. VFs are often clinically silent yet associated with decreased survival and increased risk for subsequent vertebral and nonvertebral fractures. Since VFs are among the most invalidating complications of acromegaly, dedicated investigation of bone health is recommend. In patients with acromegaly, two dimensional BMD, measured by dual X-ray absorptiometry (DXA) is insufficient predictor of fracture risk. Osteoarthritic complications in acromegalics and excess cortical bone often cause BMD overestimation. Bone size enlargement potentially causes BMD underestimation. Vertebral morphometry (VFA) provides a useful tool for time and cost effective and low radiation screening for VFs. Comprehensive evaluation and monitoring of bone health is mandatory at diagnosis, through follow-up and even after successful treatment. Prevalence and progression of VFs are expected even after biochemical control of acromegaly. Duration of the disease is a crucial factor. Assessment of bone remodeling, through bone turnover markers is important throughout long term management of acromegaly. Elevated bone turnover markers are expected in the active disease. In cured and controlled patients monitoring of bone markers is needed to detect possible low-turnover osteoporosis, particularly in hypogonadal patients, warranting additional DXA BMD follow-up. Known skeletal health risk in acromegaly requires commitment to investigate and treat additional factors affecting bone in these patients, such as untreated hypogonadism, overreplaced hypocortisolism or concomitant diabetes mellitus.