DIABETES-MELLITUS IN DOGS - RELATIONSHIP OF OBESITY TO GLUCOSE-TOLERANCE AND INSULIN-RESPONSE

  • 1 January 1984
    • journal article
    • research article
    • Vol. 45  (1) , 98-103
Abstract
The i.v. glucose-tolerance test was performed in 71 diabetic dogs (fasting glycemia > 6.70 mmol/l) and in 20 healthy dogs. All diabetic dogs were characterized by various degrees of glucose intolerance as expressed by an abnormal glucose disappearance coefficient. On the basis of the fasting plasma insulin concentration (Io), insulin peak response (IPR), the insulinogenic index (.DELTA.I/.DELTA.G) and the total insulin secretion (TIS), the diabetic dogs were classified, as follows: Type I dogs (n = 32) which had the severe clinical signs of diabetes and an absence of certain diagnostic responses: Io, IPR, .DELTA.I/.DELTA.G and TIS. Type II dogs (n = 15) which also had marked diabetic signs and an absence of IPR, .DELTA.I/.DELTA.G and TIS responses. The dogs were further subdivided into obese and nonobese groups; the Io was within acceptable limits in the nonobese group (n = 8), but was markedly increased in the obese group (n = 7). Type III dogs (n = 24) had no diabetic signs and a fasting plasma glucose < 12 mmol/l. They were also subdivided into obese and nonobese groups. The nonobese dogs (n = 13) had Io values within acceptable limits and decreased IPR, .DELTA.I/.DELTA.G and TIS. In contrast, the obese dogs had increased Io, IPR, .DELTA.I/.DELTA.G and TIS. Statistical analyses indicated that the TIS and Io were highly significant linear functions of obesity. Obesity was the most important factor accounting for the variations in insulin responses among all types of diabetic dogs, as well as within each type.