Study Indicates Link Between Severity of Diabetic Retinopathy, Subclinical CVD

The presence and severity of diabetic retinopathy (DR) may be independently associated with subclinical cardiovascular disease (CVD) in patients with type 2 diabetes (T2D), suggesting the need for a rationalized screening for coronary artery disease in patients with (T2D) and DR.

A study, published in BMJ Open Diabetes Research and Care, included 200 subjects with T2D who did not have a history of clinical CVD, as well as 60 age-matched non-diabetic subjects. In order to determine subclinical CVD, the researchers examined 2 parameters:

• Calcium coronary score (CACs)
• Composite of CACs>400UA, carotid plaque ≥3mm, carotid intima—media thickness ratio >1, or the presence of electrocardiogram (ECG) changes suggestive of previous asymptomatic myocardial infarction

The researchers also performed coronary angio-CT and assessed DR through slit-lamp biomicroscopy and retinography.

“Once coronary artery disease manifests clinically, diabetic patients continue to have a worse prognosis compared with non-diabetic patients, both during acute ischemic events and during long-term follow-up. However, the increase in CVD risk is not homogeneous in patients with DM,” the authors said.

“In fact, a significant number of these patients will never experience CV complications, and current guidelines consistently advise against the routine use of prophylactic aspirin in patients with DM. Therefore, the early identification of diabetic patients at risk of developing CVD remains a challenge.”

The subjects with T2D demonstrated higher CACs than the non-diabetic control subjects, according to the results. Moreover, age, male gender, and the presence of DR were independently related to CACs over 400.

“In addition, an inverse relationship was observed between the degree of DR and CACs <10 area under the receiver operating characteristic curve (AUROC). The variables independently associated with the composite measurement of subclinical CVD were age, diabetes duration, the glomerular filtration rate, microalbuminuria, and the presence of DR (AUROC 0.71),” authors explained. “A relationship (P <.01) was observed between the presence and degree of DR and coronary stenosis.”

The study concluded that DR is an independent risk factor for identifying subclinical cardiovascular disease. Additionally, DR confers a higher risk of subclinical cardiovascular disease than factors contained in contemporary risk equations, researchers explained.

“The detection and grading of diabetic retinopathy permit us to identify a high-risk subset of diabetic population who might benefit most from tight control of cardiovascular risk factors. In addition, given that these patients are more prone to develop cardiovascular disease, they could be used to enrich the cohorts for future intervention trials, thus reducing sample size, duration, and costs of studies,” concluded the authors.

Reference:

Simó R, Bañeras J, Hernández C, et al. Diabetic retinopathy as an independent predictor of subclinical cardiovascular disease: baseline results of the PRECISED study [published online November 11, 2019]. BMJ Open Diabetes Res Care. doi:10.1136/bmjdrc-2019-000845.