In a global prospective study of patients with relatively early-stage diabetes, microvascular and macrovascular complications were common and were associated with increased risk of subsequent hospitalization and death.
•The strongest predictor of incident complications was the known atherosclerosis or heart failure at enrollment.
•Poor glucose control and smoking were also associated with increased risk of new complications.
•These findings suggest an increased need for risk factor modification even in patients with early-stage diabetes.
Micro- and macrovascular complications are a major cause of morbidity and mortality in people with type 2 diabetes (T2D). We sought to understand the global incidence rates and predictors of these complications.
We examined the incidence of vascular complications over 3 years of follow-up in the DISCOVER study—a global, observational study of people with T2D initiating second-line glucose-lowering therapy. Hierarchical Cox proportional hazards regression models examined factors associated with development of micro- and macrovascular complications during follow-up.
Among 11,357 people with T2D from 33 countries (mean age 56.9 ± 11.7 years, T2D duration 5.7 ± 5.1 years, HbA1c 8.4 ± 1.7%), 19.0% had a microvascular complication at enrolment (most commonly neuropathy), and 13.2% had a macrovascular complication (most commonly coronary disease). Over 3 years of follow-up, 16.0% developed an incident microvascular complication, and 6.6% had an incident macrovascular complication. At the end of 3 years of follow-up, 31.5% of patients had at least one microvascular complication, and 16.6% had at least one macrovascular complication. Higher HbA1c and smoking were associated with greater risk of both incident micro- and macrovascular complications. Known macrovascular complications at baseline was the strongest predictor for development of new microvascular complications (HR 1.40, 95% CI 1.21-1.61) and new macrovascular complications (HR 3.39, 95% CI 2.84-4.06).
In this global study, both the prevalence and 3-year incidence of vascular complications were high in patients with relatively short T2D duration, highlighting the need for early risk-factor modification.