What is a common cause of hyperglycemia in clients with Cushing syndrome?

Cushing syndrome is characterized by an excessive production of cortisol, a glucocorticoid hormone. This condition can arise from various causes, such as pituitary adenomas, adrenal tumors, or ectopic production of adrenocorticotropic hormone (ACTH). The presence of elevated glucocorticoids in the body plays a profound role in glucose metabolism.

Excess glucocorticoids lead to insulin resistance, which means that the body's cells become less responsive to the action of insulin. Insulin's primary role is to facilitate the uptake of glucose from the bloodstream into the cells, especially in muscle and adipose tissues. When cells are resistant to insulin's action due to high levels of glucocorticoids, glucose remains elevated in the blood, resulting in hyperglycemia.

Additionally, glucocorticoids promote gluconeogenesis in the liver, further contributing to increased blood glucose levels. They also inhibit glucose uptake in peripheral tissues and stimulate lipolysis, which releases free fatty acids that can influence glucose metabolism. Therefore, the link between Cushing syndrome and hyperglycemia is primarily due to the excess levels of glucocorticoids that disrupt normal glucose regulation and lead to elevated blood sugar levels.