Alterations in serum concentrations of visfatin and betatrophin in dogs with hypothyroidism

BACKGROUND: Hypothyroidism in dogs is associated with obesity and altered lipid and carbohydrate metabolism. The adipokines, visfatin, and betatrophin, affect glucose tolerance. Betatrophin is involved in lipid regulation. HYPOTHESIS: Visfatin and betatrophin serum concentrations are altered in hypothyroid dogs. ANIMALS: Dogs with naturally occurring hypothyroidism (n = 25) and healthy dogs (n = 25). METHODS: Insulin, visfatin, and betatrophin serum concentrations were measured in all dogs and 19 of the hypothyroid dogs after 30 days of thyroxine treatment. Body condition score (BCS) was determined (1‐9 scale). RESULTS: Visfatin concentrations were lower in hypothyroid compared with healthy dogs (mean, 95% confidence interval [CI]; 2.0 ng/mL, 1.2‐3.3 vs 5.1 ng/mL, 3.3‐7.8; P = .004) and increased post‐treatment (3.1 ng/mL, 1.9‐4.9 vs 2.6 ng/mL, 1.6‐4.1; P = .05). Betatrophin concentrations were lower in lean to normal (body condition score [BCS], 3‐5) hypothyroid dogs compared to lean to normal healthy dogs (52 pg/mL, 9‐307 vs 597 pg/mL, 216‐1648; P = .03), but were not different between overweight (BCS, 6‐9) hypothyroid and healthy dogs (341 pg/L, 168‐695 vs 178 pg/mL, 77‐415; P = .26), and decreased post‐treatment in overweight dogs (206 pg/mL, 87‐488 vs 268 pg/mL, 112‐640; P = .004). Visfatin concentrations were higher in overweight compared with lean to normal dogs (4.7 ng/mL, 3.3‐6.6 vs 2.2 ng/mL, 1.2‐4.2; P = .04). Betatrophin concentrations were positively correlated with BCS (r = .47, P = .02) and insulin concentrations (r = .48, P = .03) in hypothyroid dogs and negatively correlated with BCS (r = −.47, P = .02) and thyroid stimulating hormone concentrations (r = −.56, P = .01) in healthy dogs. CONCLUSIONS AND CLINICAL IMPORTANCE: Hypothyroidism in dogs is associated with alterations in visfatin and betatrophin concentrations that partially resolve with thyroxine treatment.