EN02 - Dehydroepiandrosterone Sulfate (DHEAS) as a Potential Biomarker of the Etiology of Canine Cushing’s Syndrome

Abstract:

Background: In humans, dehydroepiandrosterone sulfate (DHEAS) measurement is an alternative biomarker to endogenous ACTH (eACTH), commonly used to identify Cushing’s Syndrome (CS) etiology, being normal/increased in pituitary-dependent hypercortisolism (PDH) and decreased in adrenal-dependent hypercortisolism (ADH). In dogs, information about DHEAS is scarce.

Objectives: To assess the role of DHEAS concentrations in determining CS etiology in dogs. Animals: Thirty-eight client-owned cushingoid dogs with established diagnosis (PDH versus ADH) based on functional endocrine tests, eACTH measurement and diagnostic imaging.

Methods: Multicenter, retrospective, cross-sectional study. Dogs were grouped according to CS etiology and thereafter based on sex and neutered status. DHEAS was measured with a species-specific ELISA kit using stored serum samples (-80ºC).

Results: Of the 38 dogs, 33/38 (87%) were diagnosed with PDH and 5/38 (13%) with ADH. There were 19 females and 19 males, of which 16 and 9 were neutered, respectively. Median DHEAS concentrations were significantly higher in intact males (2.45 ng/mL; interquartile range 1.02-7.80 ng/mL) than in neutered males (0.68 ng/mL; interquartile range 0.42-2.03 ng/mL; p = 0.017). Females showed a positive correlation between DHEAS and eACTH levels (r = 0.588; p = 0.008). ROC curve analysis demonstrated poor ability of DHEAS to differentiate PDH from ADH (AUC 0.430) and the Mann-Whitney test showed no significant differences in DHEAS levels between these two causes (p = 0.645). Conclusions and Clinical Importance: Despite some differences arising from sex and neutered status, DHEAS measurement does not appear to be a relevant biomarker for differentiating PDH from ADH in dogs with CS.