Effect of intensive glycemic control on cardiovascular outcomes and all-cause mortality in type 2 diabetes: Overview and metaanalysis of five trials

Abstract

More intensive diabetes control prevents microangiopathy in patients with both type 1 diabetes and type 2 diabetes. The data related to prevention of macrovascular disease in patients with type 2 diabetes are controversial. The data confirming benefit of the HbA(1c) levels below 6.5% came almost exclusively from epidemiological studies. The following article reviews the data from five large clinical randomized trials which compared the more intensive glucose lowering strategy with the standard antidiabetic treatment i.e. UKPDS, PROactive, ACCORD, ADVANCE and VADT. Metaanalysis of five trials showed a highly significant reduction of the incidence of non fatal myocardial infarction [OR 0.84 (95% CI 0.75-0.93), p = 0.001] in patients with intensive glycemic control. No significant differences were observed by combined analysis for the non-fatal stroke, cardiovascular mortality and all-cause mortality between the compared groups. The reason for the discordance of the results of the epidemiological and interventional studies is not clear. The possible explanations could include short duration of the trials to show effect of glucose lowering, as well as attenuating of the beneficial effect of better glycemic control by increased hypoglycemia-related mortality in patients with preexisting cardiovascular disease.