What is the basic difference between Type 1 and Type 2 diabetes?

• A. Type 1 is caused by lifestyle factors leading to insulin resistance.
• B. Type 2 is autoimmune destruction of insulin-producing cells.
• C. Type 1 causes insulin resistance.
• D. Type 1 is autoimmune destruction of insulin-producing cells; Type 2 involves insulin resistance and often decreased insulin production.

Answer: (D)

The key difference is where the problem lies with insulin. In Type 1 diabetes, an autoimmune process destroys the insulin-producing beta cells in the pancreas, so there is an absolute lack of insulin. In Type 2 diabetes, the body's cells become resistant to insulin, meaning glucose can’t enter cells effectively despite the presence of insulin; over time, insulin production can also decline, but the initial issue is resistance rather than a complete absence.

This distinction explains the typical treatment approach: Type 1 requires lifelong insulin replacement because the body can’t produce insulin on its own, while Type 2 is often managed first with lifestyle changes and medications that improve insulin sensitivity, with insulin added later if needed.

Statements that attribute Type 1 to lifestyle factors or insulin resistance, or that describe Type 2 as autoimmune destruction, mix up the underlying mechanisms and aren’t accurate.