Characterization and comparison of insulin resistance induced by Cushing Syndrome or diestrus against healthy control dogs as determined by euglycemic- hyperinsulinemic glucose clamp profile glucose infusion rate using an artificial pancreas apparatus.

Euglycemic-hyperinsulinemic glucose clamp (EHGC) method is a gold standard for assessing insulin resistance in humans. However, this method has yet to be commonly used with dogs, due to the requirement of frequent blood sampling for glucose measurement and adjusting glucose infusion rate (GIR). The purpose of this study was to evaluate insulin resistance, induced either by Cushing Syndrome (CS) or diestrus in dogs, as determined by GIR by EHGC, using an artificial pancreas apparatus. Twenty animals were used in this study with ten (7 females and 3 males) serving as healthy controls, four (3 females, 1 male) diagnosed with CS, and six (all females) undergoing diestrus. A higher GIR value indicates increased insulin sensitivity and lower insulin resistance. GIR of healthy control animals was determined to be within a reference range of [10.6-21.3] with a median of 15.2 mg/kg/min. In comparison, the CS group had a median of 5.4 mg/kg/min; whereas the diestrus group exhibited a median of 8.9 mg/kg/min. Insulin resistant animals suffering from CS and undergoing diestrus demonstrated reductions of 65 and 40% in GIR, respectively; thus indicating differences in degree of insulin insensitivity can be discerned using the EHGC method.

Supplementing transglucosidase with a high-fiber diet for prevention of postprandial hyperglycemia in streptozotocin-induced diabetic dogs.

Indigestible oligosaccharides have been shown to normalize blood glucose and insulin concentration thereby promoting good health and preventing diseases, such as diabetes. Transglucosidase (TG, alpha-glucosidase, enzyme code (EC) 3.2.1.20) is an enzyme capable of converting starch to oligosaccharides, such as iso-malto-oligosaccharides from maltose, via the action of amylase. The aim of this study was to evaluate whether oral administration of TG with maltose or dextrin is capable of reducing post-prandial serum glucose concentration in experimentally streptozotocin (STZ)-induced diabetic dogs fed on a high-fiber diet. Five healthy and five STZ-induced diabetic dogs were employed in this study. TG supplementation with dextrin or maltose had no detrimental effect in healthy dogs. In fact, TG and dextrin exhibited a flatlined serum glucose pattern, while reducing mean post-prandial serum insulin and glucose concentration as compared to control diet alone. When TG supplementation was tested in STZ-induced diabetic dogs under the context of a high fiber diet, a 13.8% and 23.9% reduction in mean glucose concentration for TG with maltose and dextrin, respectively was observed. Moreover, TG with dextrin resulted in a 13% lower mean post-prandial glucose concentration than TG with maltose, suggesting that dextrin may be a more efficient substrate than maltose when used at the same concentration (1 g/kg). Our results indicate that TG supplementation with diet can lead to lower postprandial glucose levels versus diet alone. However, the efficacy of TG supplementation may depend on the type of diet it is supplemented with. As such, TG administration may be useful for preventing the progression of diabetes mellitus and in its management in dogs.

Serum glycated albumin as a glycemic control marker in diabetic cats.

Measurements of glycated proteins such as serum fructosamine, glycated hemoglobin, and glycated albumin (GA) are increasingly used to complement serum glucose concentration for better management of diabetes mellitus. For example, the degree of glycemic control in diabetic cats can be determined by evaluating fructosamine concentration. Unfortunately, fructosamine tests are currently not performed in Japan, and as such, the measurement of GA may serve as a replacement test. The objectives of the current study were 2-fold. First, serum GA and fructosamine level were evaluated for positive correlation in cats as a preliminary gauge on whether serum GA use is applicable. Second, a GA percentage reference range was determined from healthy control cats for possible future diagnostic use. A positive correlation was determined for fructosamine and GA in both normal and diabetic cats. Moreover, the serum GA percentage reference interval based on control cats was determined to be 7.5-13.9% (95% nonparametric interfractile interval). Interestingly, no significant difference in serum GA percentages was observed between samples from diabetic cats with excellent glycemic control and control cats. However, good, fair, and poor glycemic control diabetic cats resulted in a significant increase in serum GA percentages in comparison to control cats. Therefore, these results indicate that serum GA may be a useful glycemic control indicator that could substitute for fructosamine to monitor glycemic control in diabetic cats.