Alterations in serum concentrations of visfatin and betatrophin in dogs with diabetes mellitus

Canine diabetes mellitus (DM) is associated with hyperglycemia and hyperlipidemia. Visfatin and betatrophin are adipokines involved in the pathophysiology of insulin resistance and deranged lipid metabolism, and are also altered in obesity. We hypothesized that visfatin and betatrophin serum concentrations are altered in diabetic dogs, irrespective of their body condition. The study included 23 newly-diagnosed DM (NDDM) dogs, 34 insulin-treated DM (ITDM) dogs and 24 healthy dogs. Body condition score was determined and fasted serum samples were collected for measurement of betatrophin, visfatin and insulin serum concentrations. Visfatin concentrations (mean, 95% CI) were lower in overweight NDDM (4.5 ng/mL, 2.5-8.1, P=0.05) and ITDM (2.8 ng/mL 1.8-4.3, P=0.006) than healthy (7.7 ng/mL, 5.0-11.7) dogs, but were not different among lean dogs, and were negatively correlated to betahydroxybutyric acid in ITDM dogs (r=-0.59, P=0.05). Betatrophin concentrations were lower in NDDM (69 pg/mL, 43-112, P<0.001) and ITDM (53 pg/mL, 34-84, P<0.001) than healthy (267 pg/mL, 167-426) dogs. Among NDDM dogs, betatrophin concentrations were higher in those with concurrent liver disease (203 pg/mL, 49-844) than those with no evidence of liver disease (19 pg/mL, 4-90, P=0.007), and were negatively correlated with glucose concentrations (r=-0.44, P=0.04) and creatinine (r=-0.60, P=0.003). Insulin concentrations were not different among NDDM and healthy dogs. Among NDDM dogs, insulin concentrations were negatively correlated to concentrations of betahydroxybutyric acid (r=-0.65, P=0.002) and were lower in dogs with concurrent kidney disease (5.6 mU/L, 2.1-15.3) compared to those with no evidence of kidney disease (20.6 mU/L, 8.0-53.2, P=0.018). In conclusion, DM in dogs is associated with alteration in visfatin and betatrophin concentrations that are not resolved by insulin treatment.