Evaluation of beta-cell sensitivity to glucose and first-phase insulin secretion in obese dogs

Am J Vet Res. 2011 Mar;72(3):357-66. doi: 10.2460/ajvr.72.3.357.


Objective: To compare beta-cell sensitivity to glucose, first-phase insulin secretion, and glucose tolerance between dogs with naturally occurring obesity of > 2 years' duration and lean dogs.

Animals: 17 client-owned obese or lean dogs.

Procedures: Frequently sampled IV glucose tolerance tests were performed with minimal model analysis on 6 obese dogs and matched controls. Glucagon stimulation tests were performed on 5 obese dogs and matched controls.

Results: Obese dogs were half as sensitive to the effects of insulin as lean dogs. Plasma glucose concentrations after food withholding did not differ significantly between groups; plasma insulin concentrations were 3 to 4 times as great in obese as in lean dogs. Obese dogs had plasma insulin concentrations twice those of lean dogs after administration of glucose and 4 times as great after administration of glucagon. First-phase insulin secretion was greater in obese dogs.

Conclusions and clinical relevance: Obese dogs compensated for obesity-induced insulin resistance by secreting more insulin. First-phase insulin secretion and beta-cell glucose sensitivity were not lost despite years of obesity-induced insulin resistance and compensatory hyperinsulinemia. These findings help explain why dogs, unlike cats and humans, have not been documented to develop type 2 diabetes mellitus.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Blood Glucose / metabolism*
  • Dog Diseases / physiopathology*
  • Dogs
  • Glucagon / metabolism*
  • Glucose Tolerance Test / veterinary*
  • Insulin / blood
  • Insulin / metabolism*
  • Insulin Resistance
  • Insulin Secretion
  • Insulin-Secreting Cells / physiology*
  • Obesity / physiopathology
  • Obesity / veterinary*


  • Blood Glucose
  • Insulin
  • Glucagon