What is the mechanism of Type 1 diabetes?

• A. Autoimmune destruction of pancreatic beta cells
• B. Insulin resistance
• C. Diet deficiency
• D. Viral infection causing insulin deficiency

Answer: (A)

Type 1 diabetes results from an autoimmune attack that destroys the pancreatic beta cells that produce insulin, leading to an absolute deficiency of insulin. This loss of insulin means glucose cannot enter many cells, causing high blood glucose and requiring lifelong insulin therapy. The autoimmune process is often revealed by autoantibodies against beta-cell proteins and a T-cell–mediated attack. This distinguishes it from insulin resistance seen in Type 2 diabetes, and from a diet deficiency as a cause; while a viral infection can sometimes act as a trigger, it is not the direct mechanism underlying the majority of Type 1 cases.