Kidney function and glucose metabolism in overweight and obese cats

Abstract

Background In people, obesity and prediabetes mellitus might predispose to chronic kidney disease (CKD). Aims To assess the association of overweight [Body condition score (BCS) >5] and glucose metabolism alterations, with established or potential markers of CKD. In addition, fructosamine and fasted blood glucose were compared as predictors of early abnormal glucose metabolism. Methods 54 clinically healthy cats were included in a cross-sectional study comprising 25 neutered males and 29 (28 neutered) females aged 7.2 (5.5–9.4) years. Two potential markers of CKD, namely urinary free active transforming growth factor-β1-creatinine ratio and urinary retinol binding protein-creatinine ratio were measured along with other parameters to assess CKD. A receiver operating curve was used to identify the best sensitivity and specificity of fructosamine to identify cats with fasting glucose >6.5 mmol/L. Results No association was found between BCS and markers of CKD. Fructosamine was greater in cats with fasting glucose >6.5 mmol/L compared to those with fasting glucose ≤6.5 mmol/L. A fructosamine concentration ≥250 µmol/L was able to detect cats with hyperglycemia with a sensitivity of 77% and a specificity of 65%. Furthermore, fructosamine was more strongly correlated with fasting glucose than albumin-corrected fructosamine (r = 0.43, p = 0.002 vs r = 0.32, p = 0.026). Cats with higher fructosamine had lower serum symmetric dimethylarginine concentrations. Conclusion The present study does not suggest an effect of obesity on renal function in domestic cats. Clinical relevance Fructosamine might be of value for the diagnosis of prediabetes mellitus in cats.