In diabetic ketoacidosis, absence of insulin leads to which metabolic change?

• A. Increased glucose uptake by cells
• B. Decreased lipolysis
• C. Increased insulin secretion
• D. Fat breakdown with ketone production

Answer: (D)

Insulin normally signals cells to take up glucose for use or storage and keeps fat breakdown in check. When insulin is absent, glucose uptake by many cells decreases, so cells can’t utilize glucose effectively and the body relies on other fuel sources. At the same time, the lack of insulin removes inhibition on lipolysis in adipose tissue, and hormones like glucagon and catecholamines promote fat breakdown. The liver then converts the liberated fatty acids into ketone bodies, which accumulate in the blood and cause metabolic acidosis. This combination of rapid fat breakdown and ketone production is what characterizes diabetic ketoacidosis.