Pre-Cushing's, Cushingoid, Syndrome-X, Hypothyroid and Metabollic SyndromeRecently, researchers have examined this condition more closely and the more specific term Insulin Resistance is now used to describe this metabolic body type. Insulin Resistance (IR) is characterized by a loss of insulin sensitivity at the cellular level. The insulin resistant horse is carbohydrate intolerant and the degree of insulin resistance can be assessed and measured as part of the diagnosis and recovery process.