What is one of the primary causes of hyperglycemia in diabetes?

In diabetes, hyperglycemia, or elevated blood glucose levels, is primarily caused by insulin resistance. Insulin resistance occurs when the body's cells become less responsive to insulin, a hormone that facilitates the uptake of glucose from the bloodstream into cells. When insulin is ineffective, glucose remains in the bloodstream, leading to elevated blood sugar levels.

This condition is particularly common in type 2 diabetes, where the body might produce sufficient insulin, but the cells do not respond to it as they should. Over time, this resistance can lead to progressively higher blood glucose levels, resulting in complications associated with diabetes.

While all body systems work together in glucose metabolism, the other options do not directly lead to hyperglycemia in the same way. Excess production of insulin would typically decrease blood glucose levels rather than increase them, and insufficient glucagon (which raises blood sugar when low) does not directly contribute to the hyperglycemic state. Decreased thyroid hormone can affect metabolism, but it is not a primary cause of hyperglycemia in diabetes. Hence, insulin resistance is the most significant factor leading to this condition.