Diabetic retinopathy predicts heart problems in type 1 diabetes

Among individuals with type 1 diabetes, diabetic retinopathy (DR) is independently associated with prevalent and incident cardiovascular disease (CVD), as reported in a study.

Researchers conducted a registry-based matched case–cohort study that included 16,547 adult patients with type 1 diabetes (median age 44.5 years, 57.6 percent men, 7.6 percent had CVD at baseline). Each patient was matched based on age and sex to five individuals without diabetes, with a total of 82,399 controls.

Of the patients, 56.5 percent had no DR, 26.8 percent had level 1 DR, 6.7 percent had level 2 DR, 1.3 percent had level 3 DR, and 8.7 percent had level 4 DR. Those with higher levels of DR were more likely to be older, have a higher Charlson comorbidity index score, and use blood pressure- and cholesterol-lowering drugs.

CVD prevalence was higher among patients with a higher level of DR (8.0 percent in level 1 vs 9.6 percent in level 2 vs 8.2 percent in level 3 vs 16.3 percent in level 4; p<0.001).

Multivariable models showed that type 1 diabetes patients not only had greater odds of having prevalent CVD (odds ratio [OR], 1.29, 95 percent confidence interval [CI], 1.20–1.38) but also had a higher risk of future CVD (within 5 years: hazard ratio [HR], 1.19, 95 percent CI, 1.08–1.30). Of note, the risk of incident CVD increased with higher levels of DR (level 1: HR, 1.33; level 2: HR, 1.95; level 3: HR, 1.71; level 4: HR, 2.39).

Meanwhile, patients without DR had a lower risk of incident CVD compared with controls (HR, 0.84, 95 percent CI, 0.72–0.97).

Finally, type 1 diabetes patients with CVD at the time of the first screening had a higher risk of incident DR during follow-up (HR, 1.23, 95 percent CI, 1.02–1.49).