Assessing Framingham cardiovascular risk scores in subjects with diabetes and their correlation with diabetic retinopathy: Comment

Dear Editor,

I read with interest the original article, “Assessing Framingham cardiovascular risk scores in subjects with diabetes and their correlation with diabetic retinopathy.”[1] I commend the authors on a well-conducted study. I however wish to bring the following errors to your notice.

In the results, it is stated that the risk factors in the high-risk and low-risk groups for diabetic retinopathy and sight-threatening retinopathy were macroalbuminuria, microalbuminuria and anemia. These are features of diabetic kidney disease, and the kidney disease is attributed to diabetes if proteinuria and diabetic retinopathy are present.[2] Diabetic retinopathy precedes diabetic nephropathy so much so that the dictum in medicine is “In diabetics with microalbuminuria and without diabetic retinopathy, look for other causes of kidney disease.”[3] Hence, macroalbuminuria, microalbuminuria and anemia cannot be considered as a risk factors for, or predictors of, diabetic retinopathy. They are the only associations of diabetic retinopathy seen in those who have diabetic retinopathy and have developed nephropathy. In the study quoted, those subjects who had microalbuminuria, macroalbuminuria and anemia were patients of diabetic kidney disease and, in all probability, had diabetic retinopthy.

This being a prospective cohort study, the conclusions would have been more valid if patients of diabetic nephropathy were excluded from the study.

Therefore, it cannot be concluded that the Framingham risk score, a global risk assessment tool for predicting the 10-year risk of developing cardiovascular risk can also predict the occurrence of diabetic retinopathy.