Investigation of serum IGF-I levels amongst diabetic and non-diabetic cats

Since insulin-like growth factor-I (IGF-I) was first discovered as a mediator of glucose homeostasis, it has been extensively investigated in diabetes research in humans, rodents and primates. To date, however, relatively little work has been carried out on this hormone in the cat, despite the pathophysiological similarities between human and feline diabetes mellitus, as well as the relatively common nature of the disease in cats. This study reports on the IGF-I concentrations of 42 insulin treated diabetic cats and 25 normal cats. Diabetic subjects were grouped according to length of insulin treatment as either short, medium or long term. Analysis of variance (ANOVA) and Fischer's pair-wise comparisons revealed that mean IGF-I levels in short-term diabetic cats were significantly lower than those in normal cats whilst mean levels in long-term diabetics were significantly higher. The direction and extent of these alterations may have implications for our understanding of the pathophysiology of feline diabetes mellitus and for the use of this hormone in the diagnosis of acromegaly in diabetic cats.