Targets for blood glucose: What have the trials told us

The challenges of diabetes treatment are to prevent or delay microangiopathic complications and macrovascular disease. Early, effective and sustained glycaemic control is advocated by all diabetes guidelines to mitigate the risks of prolonged hyperglycaemia. The post-hoc analyses of the large randomised glucose intervention trials and the long-term results of these trials have shown clearly that intensive glycaemic control may have more favourable cardiovascular effects when initiated earlier in the course of diabetes, particularly among in patients without cardiovascular disease. Based on the intervention trials a haemoglobin A1c level of less than 7.0% (<53 mmol/mol) is a generally accepted target to reduce microvascular disease and should be initiated early in the course of the diabetes. However, haemoglobin A1c targets should be individualised. Achieving a good glycaemic control without detrimental effect and preferably with benefit to the cardiovascular system and to renal function is an important challenge. When targeting a tight glycaemic control, avoidance of hypoglycaemia is crucial particularly in patients with coronary artery disease and in patients with heart failure. The cardiovascular outcomes trials performed to test the cardiovascular safety of the new glucose-lowering therapies offer compelling evidence in favour of the role of these drugs for cardiovascular prevention. Thus, both the glycaemic target and the choice of therapies should now be defined on an individual basis.