Which type of diabetes is characterized by complete insulin deficiency?

Type 1 diabetes mellitus is characterized by complete insulin deficiency due to the autoimmune destruction of the insulin-producing beta cells in the pancreas. This condition usually presents in childhood or adolescence, which is why it is sometimes referred to as juvenile diabetes. In individuals with Type 1 diabetes, the pancreas produces little to no insulin, leading to elevated blood glucose levels and the need for exogenous insulin therapy for survival and management of blood sugar levels.

In contrast, Type 2 diabetes is characterized by insulin resistance and a relative deficiency of insulin, rather than a complete absence of it. Gestational diabetes occurs during pregnancy and is often related to hormonal changes, usually resolving after delivery, while prediabetes indicates a state of higher-than-normal blood glucose levels that do not yet meet the criteria for diabetes but is still significantly associated with later development of Type 2 diabetes. Therefore, the distinctive feature of complete insulin deficiency aligns specifically with Type 1 diabetes mellitus.