Should inpatient hyperglycaemia be treated?

Two large scale randomised controlled trials in the 1990s were the first such trials to show that the control of blood glucose helped to prevent long term complications in people with types 1 and 2 diabetes.1 2 Glucose concentrations can rise not only in people with pre-existing diabetes, but also, for short periods, in people without the condition—in particular, during times of acute illness, when it is called stress hyperglycaemia.3 As discussed below, data show that raised blood glucose concentrations in people with and without a previous diagnosis of diabetes are associated with short term harm. However, whereas the benefits of good glycaemic control over a long period in people with diabetes are well established, uncertainty remains about whether treating transient hyperglycaemia, in particular in hospital inpatients, makes any difference to short term outcomes.

Sometimes the question is moot and treating hyperglycaemia is crucial—for example, in diabetic ketoacidosis or hyperosmolar hyperglycaemic states4 or in patients who are symptomatic from their hyperglycaemia. This article does not discuss these states.