Dysfunctional β cells

In type 2 diabetes (T2D) , the pancreas initially retains β-cell capacity, resulting in insulin levels that vary from above normal to below normal. However, with time, the β cell becomes increasingly dysfunctional and fails to secrete enough insulin to correct the prevailing hyperglycemia. For example, insulin levels are high in typical, obese, T2D patients but not as high as in similarly obese individuals who do not have diabetes. Thus, the natural progression of the disease results in a declining ability to control hyperglycemia with endogenous secretion of insulin (Fig. 1). Deterioration of β-cell function may be accelerated by the toxic effects of sustained hyperglycemia and elevated FFA and a proinflammatory environment.

Figure 1: Typical progression of type 2 diabetes.