Which statement best distinguishes Type 1 diabetes from Type 2 diabetes?

• A. Type 1 autoimmune beta-cell destruction leading to absolute insulin deficiency
• B. Type 1 is primarily obesity-related insulin resistance
• C. Type 1 results from impaired glucagon production
• D. Type 1 is characterized by excess hepatic glucose production

Answer: (A)

Type 1 is defined by autoimmune attack on pancreatic beta cells, which leads to absolute insulin deficiency. Because the body stops producing insulin altogether, people with Type 1 require insulin therapy from diagnosis and often present with rapid onset, sometimes in youth, and may have detectable autoantibodies.

This makes the statement about autoimmune beta-cell destruction the best way to distinguish Type 1 from Type 2. Type 2, by contrast, is mainly driven by insulin resistance with relative insulin deficiency that develops over time, and it is more closely linked to obesity and metabolic factors. The idea of impaired glucagon production isn’t a defining feature of Type 1, and excess hepatic glucose production occurs in both types when insulin is insufficient, so those descriptions don’t uniquely separate Type 1 from Type 2.