Endocrine Abstracts

The skeleton consists of cortical bone and trabecular (cancellous) bone. Cortical bone, which comprises 80% of the skeleton, is designed to provide rigidly and strength and is predominantly found in the long bones, e.g. at the femur. Cancellous bone has a more flexible design with interconnecting trabecles, and is metabolically more active then cortical bone. The balance between formation and resorption is essential for maintaining a normal bone mass and skeletal integrity. Disruptions in the ratio of bone formation and resorption in favour of resorption will ultimately lead to progressive bone loss and increased bone fragility. In daily clinical practice, Bone Mineral Density (BMD) measurements using DXA remain the corner stone for the diagnosis of osteoporosis. BMD has been shown to be a strong predictor for fractures however there is increasing evidence that factors other than BMD determine bone fragility and thus fracture risk. These underlying secondary risk factors for fractures should be taken into account in the assessment of an individual’s fracture risk and are usually present in patients with pituitary diseases. These secondary factors may be identified by medical history and evaluated and confirmed using appropriate laboratory investigations including thyroid, gonadal function. But Cushings disease, Acromegaly or growth hormone deficiency should be considered as well. Besides laboratory examinations, additional radiological evaluation should take place when evaluating these patients. The presence of one or more vertebral fractures has been shown to represent a strong independent predictor for future vertebral and for non-vertebral fractures. Vertebral fractures have been shown to be associated with increased morbidity and mortality. Increased incidence of Vertebral fractures have been reported in patients with Acromegaly and Growth Hormone deficiency where bone mass might even be within the normal range. Therefore other techniques should also be explored to further evaluate fracture risk in patients with pituitary diseases.