The effect of intensive glucose control on all-cause and cardiovascular mortality, myocardial infarction and stroke in persons with type 2 diabetes mellitus: a systematic review and meta-analysis

We performed a meta-analysis of studies evaluating the effect of intensive glucose control on major adverse cardiovascular events in patients with type 2 diabetes from 1990 to 2009. A search of the published literature and the Cochran Central Register for Controlled Trials was performed using pre-specified inclusion criteria consisting of randomised controlled trials evaluating intensive glycaemic control and reporting the individual endpoints of all-cause mortality, non-fatal myocardial infarction, and non-fatal stroke. Incident rate ratios for these endpoints were calculated using standard meta-analytic techniques of pooled data from eligible trials. Six reports from four randomised trials including 27,544 patients met the pre-specified inclusion criteria. Mean follow-up was 5.4 years; haemoglobin A(1C) at study end was 6.6% vs. 7.4% in patients randomised to intensive compared with conventional glucose control. Intensive glucose control did not affect the incident rate ratio for all-cause mortality (1.01, 95% confidence interval 0.86-1.18, p=0.54) or stroke (1.02, 95% confidence interval 0.88-1.20, p=0.62). However, there was a statistically significant 14% reduction in non-fatal myocardial infarction in patients randomised to intensive glucose control (0.86, 95% confidence interval 0.77-0.97, p=0.015). Although intensification of glucose control did not affect mortality or non-fatal stroke, the risk for non-fatal myocardial infarction was significantly reduced in patients with type 2 diabetes.