Ketoacidosis results from deficiency of which hormone?

• A. Insulin
• B. Epinephrine
• C. Glucagon
• D. Thyroxine

Answer: (A)

Insulin deficiency drives ketoacidosis. Insulin normally inhibits fat breakdown and ketone production. Without it, hormone-sensitive lipase in adipose tissue stays active, releasing free fatty acids into the blood. The liver converts these fatty acids to acetyl-CoA and, because carbohydrate availability is limited, diverts excess acetyl-CoA into ketone body production (acetoacetate and beta-hydroxybutyrate). These ketones accumulate and lower blood pH, causing metabolic acidosis. Other hormones like glucagon or epinephrine can promote ketogenesis, but the fundamental trigger for ketoacidosis is the lack of insulin. Thyroxine isn’t driving this process.