What characterizes diabetes insipidus?

Diabetes insipidus is characterized by insufficient production of antidiuretic hormone (ADH), which is produced by the pituitary gland. ADH plays a crucial role in regulating the body's water balance by promoting the reabsorption of water in the kidneys. When there is not enough ADH, the kidneys are unable to retain water effectively. This results in excessive production of dilute urine and increased thirst, leading to dehydration if the fluid loss is not adequately compensated.

The other choices relate to different conditions: excessive insulin production is associated with hypoglycemia or conditions like insulinoma; poor response to insulin is a hallmark of diabetes mellitus, particularly type 2; and resistance to glucose pertains to the body’s inability to utilize glucose properly, which is also associated with diabetes mellitus. Thus, the defining feature of diabetes insipidus is the lack of adequate ADH, making the correct choice directly linked to the pathophysiology of the condition.