Effects of intensive glucose control on incidence of cardiovascular events in patients with type 2 diabetes: A meta-analysis

Background. The effects of intensive glucose control over conventional glucose control on cardiovascular outcomes of patients with type 2 diabetes remain uncertain. Methods. We searched MEDLINE, EMBASE, and the Cochrane database to identify randomized controlled trials that compared the effects of intensive glucose control and conventional glucose control, on cardiovascular events in patients with type 2 diabetes. Results. Seven trials involving 34,144 participants with type 2 diabetes were included. Intensive glucose control significantly reduced major cardiovascular events by 10% (relative risk (RR) 0.90, 95% CI 0.85-0.96; P - 0.0006), and non-fatal myocardial infarction by 16% (0.84, 95% CI 0.76-0.93; P = 0.0006) at the expense of increased incidence of severe hypoglycemia (2.30, 95% CI 1.74-3.03; P < 0.00001), while all-cause mortality, cardiovascular death, non-fatal stroke, and heart failure were similar between the two groups. Subgroup analyses showed that patients with longer follow-up duration, shorter diabetic duration, less glycosylated hemoglobin (HbA1c) reduction, higher HbA1c concentration at follow-up, and lower base-line HbA1c benefited more from intensive glucose control. Conclusion. An intensive glucose control strategy can effectively reduce the risk of major cardiovascular events but at the expense of a significantly increased risk of severe hypoglycemia in patients with type 2 diabetes.