Question

The primary pathophysiological mechanism in type 1 diabetes mellitus is

• A. Insulin resistance in peripheral tissues
• B. Autoimmune destruction of pancreatic β-cells
• C. Impaired incretin secretion
• D. Excess hepatic glucose uptake

Hint:

Diabetes mellitus comes in two main types, and they have completely different root causes.

Answer 1

The Correct Option is B

Step 1: Distinguish Type 1 from Type 2 diabetes.
There are two main types of diabetes mellitus. Type 1 is an autoimmune disease. Type 2 is a metabolic disease driven by insulin resistance. The question asks specifically about Type 1.

Step 2: Evaluate Option 1 (insulin resistance).
Insulin resistance in peripheral tissues is the primary mechanism in Type 2 diabetes mellitus, not Type 1. Rule it out.

Step 3: Evaluate Options 3 and 4.
Impaired incretin secretion is a secondary feature of Type 2 diabetes, not Type 1. Excess hepatic glucose uptake does not describe either type correctly.

Step 4: Focus on Option 2 (autoimmune destruction of beta cells).
In Type 1 diabetes, the body's own immune system attacks and destroys the insulin-producing beta cells of the islets of Langerhans in the pancreas. CD8+ T cells are mainly responsible for this destruction. Once beta cells are gone, the patient can no longer produce insulin at all and must receive it from outside.

Step 5: Confirm the correct answer.
The primary pathophysiological mechanism in Type 1 diabetes mellitus is autoimmune destruction of pancreatic beta cells.

Answer: Option (2) — Autoimmune destruction of pancreatic β-cells