Relationship of hyperlipidemia and gallbladder sludge scores in dogs with hyperadrenocorticism

Hyperadrenocorticism (HAC) and hyperlipidemia have been identified as the causes of cholestatic disease in dogs. However, the possibility of direct association of HAC with a cholestatic disease or secondary hyperlipidemia-induced cholestatic disease in dogs with HAC has not been elucidated. This study aimed to evaluate the differences in serum triglyceride (TG), total cholesterol (TC) and basal cortisol (BC) concentrations based on the gallbladder (GB) sludge score in dogs with HAC. This study was a retrospective cohort study. In total, 36 dogs with pituitary-dependent hyperadrenocorticism (PDH) were divided into six groups (GB scores 0-5) based on the ultrasonographic evaluation of the GB at the time of diagnosing HAC. Serum concentrations of TG, TC and BC were measured and compared among the six groups. Additionally, correlation analysis was conducted to determine the relationships between the variables. The median serum TG concentration was significantly higher (P = 0.003) in the cholestatic disease group (GB score 1- 5) (median, 102.0 [range, 36.0-1121] mg/dL) than that in the normal group (GB score 0) (median, 50.0 [range, 50.0-56.0] mg/dL). There was a positive correlation between serum TG concentrations and the GB sludge score (P = 0.035, rs = 0.353). Furthermore, there was no significant difference in serum TC and BC concentrations among the groups and no correlation between serum TC or BC concentration and the GB sludge score was observed. Our results suggest that an increased serum TG concentration could be associated with the severity of cholestatic disease in dogs with HAC.