Which hormone is primarily deficient in type 1 diabetes?

• A. Insulin
• B. Glucagon
• C. Cortisol
• D. Adrenaline

Answer: (A)

Insulin is the hormone primarily deficient in type 1 diabetes because the disease results from autoimmune destruction of pancreatic beta cells that produce insulin. Without insulin, the body's cells can’t take up glucose from the blood, so glucose builds up in the bloodstream while cells run low on fuel. Glucagon isn’t deficient; it’s the hormone that raises blood glucose by signaling the liver to release stored glucose, and in type 1 diabetes its effect is unopposed by the missing insulin. Cortisol and adrenaline influence glucose levels but are not the missing hormone responsible for the condition. So the deficiency driving type 1 diabetes is insulin, which is why insulin therapy is essential for survival.