EN10 - Effect of Hypercortisolism on Bone Mineral Density Assessed by Computed Tomography

Abstract:

Background: Clinically significant osteoporosis and vertebral fractures are common in humans but rare in dogs with naturally occurring hypercortisolism (NOH). Decreased bone mineral density (BMD) has been reported in a small cohort of eight dogs with NOH but only in comparison to healthy dogs. Hypothesis/

Objectives: To assess BMD by quantitative CT in a larger cohort of dogs with NOH compared to those with adrenal masses unrelated to NOH and a hospital control group. Animals: 18 dogs with NOH (Group 1), 18 dogs with unrelated adrenal masses (Group 2) and 18 dogs with non-adrenal illness (Group 3) sex-, age- and weight-matched to those with NOH.

Methods: Retrospective case record analysis including dogs where abdominal CT (SOMATOM Scope, Siemens) had been performed and contained L3 and/or L2 vertebrae and excluding those receiving exogenous glucocorticoids or having a disease impacting bone or calcium metabolism. An asynchronous phantom was used for measuring BMD.

Results: Group 1 had significantly (p = 0.021) lower BMD at L2 than Group 3. However, there was no significant difference in either vertebra in nine dogs with pituitary-dependent hypercortisolism (PDH) compared to the other groups. Dogs with a functional adrenal tumour (FAT) had significantly lower BMD at L2 than Group 3 (p = 0.025) and at L3 than Group 2 and Group 3 (p = 0.021 and 0.046, respectively). Conclusions and Clinical Importance: Dogs with FAT, but not those with PDH, have decreased BMD on quantitative CT. The clinical relevance and pathways remain unclear and further studies are warranted.