Pathophysiology of Prediabetes Hyperinsulinemia and Insulin Resistance in the Cardiovascular System

Hyperinsulinemia refers to an elevated level of circulating insulin (80 and 100 µU/mL), often leading to metabolic disorders such as obesity, insulin resistance, and type 2 diabetes (T2D). There is no precise and universally accepted definition of hyperinsulinemia and insulin resistance. The literature in the field remains unclear regarding whether insulin resistance precedes the development of hyperinsulinemia. Recently, a new hypothesis has been proposed suggesting that chronic hyperinsulinemia precedes and causes insulin resistance. The causes of the initiation of hyperinsulinemia, insulin resistance, and type 2 diabetes are multifactorial. Thus, it is not easy to define in general. Recent work demonstrates that the main prediabetic factor leading to insulin resistance is chronic hyperinsulinemia. However, recent work in the literature proposes that relatively long-term hyperinsulinemia does precede insulin resistance and already promotes cardiovascular remodeling. This later may lead to the development of vascular diseases such as hypertension. Thus, defining hyperinsulinemia and insulin resistance, as well as their signaling pathways implicated in the development of type 2 diabetes (T2D), needs to be clarified.