A review of basal insulins.

Tight glycaemic control (ideally, HbA1c<7%) is central to reducing the risk of long-term complications of diabetes. This approach, for both Type 1 and Type 2 diabetes, commonly involves the use of basal insulin, and must be achieved with minimal risk of hypoglycaemia (particularly nocturnal episodes). Indeed, concern around hypoglycaemia is a major barrier to achieving tight glycaemic control, and is a common problem with those protracted-acting insulins most frequently used in clinical practice for basal insulin supply. Other drawbacks include inter- and intra-patient variability that compromises dosing reproducibility and unsuitability for single daily dosing. New long-acting human insulin analogues with action profiles designed to overcome these problems are now available in clinical practice or are under evaluation in clinical trials. Clinical evidence suggests efficacy and safety advantages for these analogues over NPH insulin (the most commonly used basal insulin), and may bring closer the goal of tight glycaemic control in patients with diabetes.