Comparing the incidence of major cardiovascular events and severe microvascular complications in patients with type 2 diabetes mellitus: A systematic review and meta-analysis

Abstract

Type 2 diabetes mellitus (T2DM) causes both macrovascular and microvascular complications. However, currently, selection of glycemic measures and their thresholds to diagnose T2DM, and efficacy outcomes in evaluation of anti-diabetic drugs is predominantly informed by the relation of T2DM to microvascular complications. We can be severely mistaken on T2DM by neglecting macrovascular complications which are generally more severe, if they also occur more commonly than microvascular complications. To compare the incidence of major cardiovascular events (MACEs) and severe microvascular complications (SMICs) in T2DM patients. MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials were searched from inception to September 2017. Cohort studies or trials of T2DM patients aged 18 years or older that reported incidence of both MACEs and SMICs were included. MACEs were defined as nonfatal myocardial infarction and stroke, and cardiovascular death, while SMICs included serious retinopathy, nephropathy and diabetic disorder. The relative risk (RR) was estimated as the incidence of MACEs divided by that of SMICs in same patients and combined with meta-analysis in a random-effect model. Twelve studies with a total of 16 cohorts and 387376 patients were included, and the combined RR was 2.02 (95%CI: 1.46–2.79). The higher incidence of MACEs remained in various subgroup and sensitivity analyses. Patients with T2DM are much more likely to develop MACEs than SMICs. By taking more serious consequences and relatively higher incidence into consideration, macrovascular complications deserve more emphasis in developing the diagnostic criteria of T2DM and in evaluating the efficacy of anti-diabetic drugs.