How important is blood glucose control in diabetes?

Abstract

Diabetes is now a common condition, with rapidly increasing prevalence globally. Individuals with diabetes have a two to three-fold increased risk of developing macrovascular complications such myocardial infarction and stroke, compared with those without diabetes. Premature morbidity and mortality in people with diabetes is also associated with microvascular complications, including retinopathy and kidney disease. In 2008, the results of three large-scale randomised trials of intensive blood glucose control failed to provide evidence in the reduction of macrovascular disease in people with type 2 diabetes; indeed in one trial, intensive glucose control was associated with poorer outcomes. These findings were unexpected, in light of the epidemiological associations between blood glucose levels and both microvascular and macrovascular disease. Some proposed that the absence of benefits (or presence of harm) from intensive blood glucose lowering might reflect adverse effects of excess severe hypoglycaemia, or the concept of “metabolic memory”, whereby any beneficial effects may be observed only several years after the onset of tight blood glucose control. In this presentation I will provide an overview of the trial evidence relating to blood glucose control in people with type 2 diabetes, including recently reported data on long-term follow-up in the pivotal trials, ostensibly addressing the issue of “metabolic memory”.