Ophthalmologists play an essential role in mitigating cardiovascular and cerebrovascular risks associated with moderate to severe nonproliferative and proliferative diabetic retinopathy, according to research published in Ophthalmology.
The study shows that diabetic retinopathy is significantly associated with the future risk of cerebrovascular accident, myocardial infarction, congestive heart failure, and death. Higher degrees of retinopathy appear to carry a heightened risk for each outcome, according to researchers.
To evaluate the relationship between diabetic retinopathy severity and the risk for future cardiovascular or cerebrovascular events and all-cause mortality, researchers conducted a retrospective cohort study of patients with type 2 diabetes.
Participants were patients at Kaiser Permanente Southern California. All underwent a diabetic retinopathy screening, with degree of diabetic retinopathy determined via fundus photographs and evaluated at a centralized clinical reading center. The primary study outcome was the 5-year risk of first-time cerebrovascular accident, myocardial infarction, congestive heart failure, and all-cause mortality.
The cohort included 107,218 adults with type 2 diabetes, 104,118 of whom had interpretable fundus photographs. After exclusion, 77,376 were available for analysis (average age, 59.7 years; 53.6% male); of these, 12,756 had minimal nonproliferative diabetic retinopathy, 2620 had moderate to severe nonproliferative diabetic retinopathy, and 607 had proliferative diabetic retinopathy. Those with at least moderate to severe disease were more likely to be Hispanic males with higher HbA1c, low-density lipoprotein cholesterol, urine microalbumin, and creatinine ratio.
Investigators found that higher degrees of retinopathy were associated with higher crude event rates and rate ratios across all 4 outcomes. A multivariable time to event analysis, which controlled for patient demographic and clinical characteristics, found that “the effects of all levels of retinopathy were significant” at the 95% level across all study outcomes, with an increase in effects associated with increased severity of retinopathy.
Specifically, elevated HbA1c values, greater diabetes duration, history of hypertension and/or tobacco use, and higher urine creatinine levels were all significantly associated with a higher risk for all 4 study outcomes. Conversely, being a woman, Hispanic or Asian race, and higher high-density lipoprotein cholesterol and estimated glomerular filtration rate levels were associated with a lower risk of experiencing the study outcomes.
Study limitations include the use of screening program data, which may have under-represented more severe forms of diabetic retinopathy, a potential underestimation of diabetes duration in study participants, and the possibility of unaccounted confounders.
“Ophthalmologists can serve an important conduit for ensuring better diabetes and cardiovascular control given their frequent contact with diabetic patients, especially those with worse diabetic disease,” the research concludes. “These findings highlight the important role ophthalmologists can play in the management of diabetes and the prevention of vascular disease and death.”
Modjtahedi BS, Wu J, Luong TQ, Ghandi NK, Fong DS, Chen W. Severity of diabetic retinopathy and the risk of future cerebrovascular disease, cardiovascular disease, and all-cause mortality. Ophthalmology. Published online December 24, 2020. doi:10.1016/j.ophtha.2020.12.019