Why, when and how to initiate insulin therapy in patients with type 2 diabetes.

Type 2 diabetes is characterised by insulin resistance and progressive beta-cell deterioration. As beta-cell function declines, most patients with type 2 diabetes will require insulin therapy. Clinical studies show that tight control of blood glucose levels prevents the development of the microvascular and macrovascular complications caused by diabetes. Insulin is the most potent drug currently available to achieve tight glycaemic control; however, often it is not used early or aggressively enough for patients to achieve the glycaemic targets needed to prevent chronic complications. New basal insulin analogues and premixed insulin analogues, which have more physiological time-action profiles compared with human insulin formulations, offer flexibility and convenience, thereby improving quality of life. It is crucial that doctors initiate insulin therapy as soon as other diabetes therapies are no longer effective. This article reviews the improvements provided by basal insulin analogues, premixed insulin analogues, and insulin delivery systems; provides sample algorithms for initiating and titrating the various insulin analogue preparations; and discusses how to individualise treatment regimens to maximise outcomes in patients with type 2 diabetes.