Insulin Pump for Type 2 Diabetes

Progressive hyperglycemia in type 2 diabetes results from a progressive β-cell failure together with a state of insulin resistance (1). Insulin deficiency worsens with the natural progression of type 2 diabetes, explaining the escape from oral antihyperglycemic agents and the need for exogenous insulin therapy (2).

The use of external pumps in patients with type 2 diabetes is a recent practice compared with that in type 1 diabetes, and its use is still debated. In only a few countries, such as in France and Israel, continuous subcutaneous insulin infusion (CSII) using an external pump is an alternative in type 2 diabetes that the health authorities have allowed for reimbursement. The rationale for using pump therapy was first suggested by its use in case reports of type 2 diabetes with extreme insulin resistance and poor glycemic control (3–6). In such patients, insulin was administered transiently by intravenous insulin infusion allowing lower mean glucose level despite a 40% reduction of insulin requirements. The sequential use of 4-week intravenous insulin infusion followed by 1-year CSII in a group of patients with type 2 diabetes patients poorly controlled despite very high insulin requirements allowed a dramatic reduction of HbA_1c (−3%, −9 mmol/mol), while insulin requirements were reduced by one-third. Such beneficial effects of CSII were attributed to increased insulin sensitivity assessed by the hyperinsulinemic-euglycemic clamp study (7). These observations raised the question as to whether insulin continuous administration by a pump device gives an advantage compared with the conventional approach of insulin intensification by multiple daily injections (MDIs). The evidence base is still under debate and will be discussed in this review.