Glycaemic status and cardiovascular disease in type 2 diabetes mellitus: re-visiting glycated haemoglobin targets for cardiovascular disease prevention.

Cardiovascular disease (CVD) is the leading cause of death among people with type 2 diabetes. Recent attention has focused on chronic hyperglycaemia as an additional risk factor in people with diabetes since their excess CVD risk is not entirely explained by traditional cardiovascular risk factors. Clinical trials of intensive glucose control to reduce CVD events have been equivocal, but recent epidemiological studies have shown that HbAlc, a measure of chronic hyperglycaemia, predicts incident cardiovascular events. This review, which focuses on type 2 diabetes, summarizes (i) the epidemiological literature examining the relation between glycaemic status, as assessed by glycated haemoglobin (HbAlc) and CVD, (ii) the controversy regarding treatment goals for HbAlc in terms of preventing microvascular disease vs. macrovascular disease and (iii) on-going clinical trials of intensive glycaemic control for CVD prevention.