What is the primary cause of type 1 diabetes mellitus?

The primary cause of type 1 diabetes mellitus is the autoimmune destruction of pancreatic beta cells. In type 1 diabetes, the immune system mistakenly attacks and destroys these insulin-producing cells in the pancreas. As a result, the body is unable to produce sufficient insulin, leading to elevated blood glucose levels. This condition typically arises in childhood or adolescence, although it can occur at any age.

This autoimmune response can be triggered by various factors, including genetic predispositions and possible environmental factors, although the exact cause of the immune system's attack is not fully understood. In contrast, options related to dietary choices, insulin resistance, and obesity are more closely related to type 2 diabetes mellitus, where insulin resistance plays a crucial role. Understanding the distinction between type 1 and type 2 diabetes is essential for appropriate diagnosis and management.