INS and Hyperglycemia: Previous hypotheses for the development of IR in cats suggested that the long-term consumption of high-carbohydrate diets leads to exhaustion of β cells due to hyperglycemia and ultimately, loss of β cell insulin secretion (Rand et al., 2004), which was observed in cats when hyperglycemia (30 mmol/L) was induced over a 10-d period (Zini et al., 2009).