Macular edema, cardiovascular disease associated in type 2 diabetes

Patients with type 2 diabetes and diabetic macular edema (DME) or proliferative diabetic retinopathy (PDR) had a higher risk of incident and fatal cardiovascular disease (CVD) compared to diabetic patients without these conditions, a meta-analysis found.

To examine the association, authors included 7,604 individuals with type 2 diabetes from eight prospective, population-based studies with data on photographic-based diabetic retinopathy grading, follow-up visits, and well-defined incident CVD end points, including coronary heart disease, stroke, or death from cardiovascular causes. Results were published May 4 by JAMA Ophthalmology.

The prevalence of DME was 4.6%, and the prevalence of PDR was 7.4%. After a mean follow-up of 5.9 years (range, 3.2 to 10.1 years), there were 1,203 incident CVD events, including 916 coronary heart disease cases.

Both DME and PDR were related to an increased risk of first-ever CVD (incidence rate ratios [IRRs], 1.65 [95% CI, 1.24 to 2.19] for DME and 1.28 [95% CI, 1.03 to 1.58] for PDR) and fatal CVD (IRRs, 2.85 [95% CI, 1.43 to 5.68] for DME and 1.85 [95% CI, 1.04 to 3.28] for PDR). The authors noted that the associations were consistent after multivariable adjustment for vascular risk factors, including smoking, systolic blood pressure, use of hypertension medication, total cholesterol level, and body mass index. When duration of diabetes, use of any treatment for diabetes, and HbA1c level were included in the multivariable model, the association between the presence of vision-threatening diabetic retinopathy and fatal CVD remained significant (hazard ratio [HR], 2.20; 95% CI, 1.10 to 4.39).

Also, DME and PDR were related to an increased risk of first-ever coronary heart disease (IRRs, 1.57 [95% CI, 1.16 to 2.14] for DME and 1.39 [95% CI, 1.09 to 1.76] for PDR) and fatal coronary heart disease (IRRs, 3.55 [95% CI, 1.76 to 7.15] for DME and 2.11 [95% CI, 1.19 to 3.76] for PDR). These associations were consistent after multivariable adjustment for vascular risk factors. When duration of diabetes, use of treatment for diabetes, and HbA1c level were included, the association between the presence of vision-threatening diabetic retinopathy (HR, 2.47; 95% CI, 1.21 to 5.06) and fatal coronary heart disease remained significant.

Patients with DME or PDR should be followed more actively to prevent cardiovascular disease, the authors noted. “Our findings suggest that the presence of DME or PDR may be a marker of generalized microvascular disease, which may contribute to the development of CVD in persons with diabetes,” they wrote.