Evaluation of insulin resistance in two kinds of South American camelids: Llamas and alpacas

Insulin resistance was evaluated in South American camelids, Ilamas and alp acas, by use of the minimal model test and the insulin tolerance test. Anim als were catheterized for long-term studies and tamed to minimize stress du ring evaluation, Results indicated a low insulin sensitivity index (S-I) = 0 to 0,97, median = 0.39 x 10(-4) min/uIU x mi, about a fifth the value in other mammals and humans. The K-ITT was between 1.43 and 3.19 %/min, also s ignificantly lower than that reported for humans. Glycosylated hemoglobin c oncentration was 6%, and Hb(A1c) concentration was 5.5%; red blood cell lif etime, as measured by use of the Cr-51 method, was 120 days, similar to the value in humans. We concluded that Ilamas and alpacas have naturally highe r blood glucose concentration than do humans and other mammals during the g lucose tolerance test, Using the same mathematical tools to evaluate glucos e metabolism as those used in people, South American camelids appear to be resistant to insulin. Thus, the South American camelid may be a useful new animal model for the study of sugar metabolism and various facets of diabet es mellitus, especially protection from the deleterious effects of glycosyl ation.