The effect of intensive glycaemic control on cardiovascular outcomes

The relationship between glycaemia and cardiovascular disease remains controversial. For patients with type 1 diabetes in the Diabetes Control and Complications Trial, intensive glycaemic control reduced microvascular outcomes and, on longer term follow-up, a significant reduction in macrovascular events was observed. For patients with recently diagnosed type 2 diabetes, the findings in the United Kingdom Prospective Diabetes Study were similar; intensive glycaemic control reduced microvascular events during the intervention phase of the study, and a reduction in macrovascular events was observed on longer follow-up. More recently, the Action in Diabetes and Vascular Disease: Preterax and Diamicron Modified Release Controlled Evaluation study showed a microvascular benefit of more intensive blood glucose control in patients with longstanding diabetes, whereas the Action to Control Cardiovascular Risk in Diabetes study showed harm if this was performed rapidly, with increase in weight, hypoglycaemia and mortality. Collectively, these studies suggest that slow and steady intensive control of glycaemia improves outcomes in people with diabetes, and that to reduce mortality this should be commenced early in the management of patients with type 2 diabetes.