To review the recent studies on intensive glucose control and the risk of cardiovascular disease (CVD) in type 2 diabetes, to discuss potential reasons for discordant results among recent trials, and to comment on implications for clinical practice.
Three large randomized controlled trials on the effect of tight glycemic control (TGC) on CVD in patients with type 2 diabetes have been published within the last year, along with the cardiovascular outcomes from the long-term follow-up of the United Kingdom Prospective Diabetes study. This narrative review of the methods and results of these trials reveals cardiovascular benefit from early institution of TGC, and lack of benefit or potential harm with intensification of glucose control late in the course of type 2 diabetes or after CVD has developed. Also, the benefits of TGC may be outweighed by weight gain and hypoglycemia. All trials had fewer cardiovascular events than anticipated, likely due to improvements in treatment of other cardiovascular risk factors.
In addition to controlling cardiovascular risk factors, patients with type 2 diabetes should aim for good glycemic control (HbA1c<7%) soon after the diagnosis of diabetes to prevent macrovascular as well as microvascular complications. Glycemic targets should be individualized as diabetes progresses, comorbidities develop, and to avoid having the side-effects of therapy (hypoglycemia and weight gain) predominate.
aNewton-Wellesley Hospital, Newton, USA
bMassachusetts General Hospital Diabetes Center and Harvard Medical School, Boston, Massachusetts, USA
Correspondence to Deborah Wexler, Massachusetts Hospital Diabetes Center, Bulfinch 408, Boston, MA 02114, USA Tel: +1 617 726 8767; fax: +1 617 726 6781; e-mail: firstname.lastname@example.org