Abstract
Aim for glycated haemoglobin lower than 6.5%, but without using highly intensive treatment On 8 February 2008, the glucose lowering arm of a large ongoing randomised controlled trial (ACCORD) of people with type 2 diabetes at high risk of cardiovascular events was stopped 18 months early because of concerns about safety. Intensively lowering blood glucose to a target below current recommendations (glycated haemoglobin (HbA1c) <6.0%) increased the risk of death compared with a less intensive standard treatment strategy (HbA1c 7.0-7.9%). This amounted to an excess of deaths of 3/1000 participant years on a background control rate of 10/1000 participant years.1 So what do these findings mean for clinical practice? Several evidence based or consensus guidelines in recent years have recommended target values of HbA1c <6.5% or <7.0%.2 3 Targets of this kind, however, are rarely tested in clinical trials, which usually compare strategies of different intensity rather than treatment to different targets. Accordingly, the evidence used in target setting is usually secondary—it comes from findings embedded within the results of such treatment trials. This evidence is often supplemented by data from observational studies and within study analyses. For type …