Background: Adrenomegaly is a common finding on ultrasound in cats with chronic kidney disease (CKD). However, it is unclear if this translates into changes in adrenal or kidney function. Hypothesis/
Objectives: We propose adrenal size on ultrasound is correlated with cortisol reserves, kidney size and biomarkers of kidney function in cats with CKD.
Methods: A prospective study was performed after ethical approval. Twenty-six (n = 26) cats with CKD were recruited from the pool of patients referred to a veterinary teaching hospital. Adrenal caudal pole thickness and kidney size were measured by ultrasound. A complete blood biochemistry panel and adrenocorticotrophic hormone (ACTH) stimulation test using 125 µg tetracosactide (Cosacthen) administered intramuscularly were performed. Resting cortisol (T0) and post-ACTH cortisol (T1) were measured by chemiluminescence (IMMULITE® 1000). Data was log-transformed to ensure normality and Pearson’s correlation coefficient was used to assess the link between variables.
Results: Right adrenal size was correlated with left kidney size (LK) (r = -0.317, p = 0.032), T1 (r = 0.407, p = 0.039), delta-cortisol (T1-T0) (r = 0.478, p = 0.018) and serum creatinine (r = 0.436, p = 0.026). Left adrenal size was correlated with LK (r = -0.376, p = 0.010), serum creatinine (r = 0.525, p = 0.006), phosphate (r = 0.404, p = 0.041), blood urea nitrogen (r = 0.391, p = 0.048) and symmetric dimethylarginine (r = 0.556, p = 0.004). Conclusions and clinical importance: Adrenal size appears to be linked to cortisol-release capability and kidney function in cats with CKD.
