Professor Ohio State University Columbus, OH, United States
Abstract: Background – Leptin is a satiety-inducing hormone secreted by adipose tissue and eliminated by the kidney. Renal dysfunction has been shown to increase serum leptin concentrations, which may cause appetite dysregulation. Studying appetite regulating hormones, such as leptin, will improve our understanding of inappetence in chronic kidney disease (CKD) cats. Objectives/Hypothesis – To evaluate serum leptin concentrations in cats with and without CKD. We hypothesized that serum leptin concentrations will be significantly higher in cats with CKD compared to clinically normal cats. Animals – 30 cats with stable CKD (IRIS Stages 1-4) and 12 normal cats. Methods – Serum biochemistry, CBC, T4 and urinalysis were performed to confirm health status and IRIS stage. Exclusion criteria included administration of an appetite stimulant (mirtazapine, gabapentin) within the past 24 hours, a body score condition >7/9, and diabetes, or other uncontrolled systemic disease. Fasted serum samples were collected and analyzed using a Rat Leptin ELISA Kit (RAB0335, Millipore) according to assay instructions. This kit was validated for feline use. Results – Serum leptin concentrations were significantly higher in cats with CKD (median = 13.0 ng/mL, range = 0.104 ng/mL – 162 ng/mL) compared to clinically normal cats (median = 2.3 ng/mL, range = 0.065 ng/mL – 90.6 ng/mL) (p = 0.03). Serum leptin concentrations were not significantly correlated with serum creatinine (r = 0.246, p = 0.12). Conclusion – Increased serum leptin concentrations in cats with CKD could result in appetite dysregulation and may contribute to weight loss and decreased appetite.
