ACE and diabetic retinopathy: For diabetic nephropathy analysis, sex, age, BMI, systolic and diastolic blood pressure, duration of diabetes, diabetic retinopathy stage, HbA1c, history of LEA, history of tobacco smoking, use of lipid lowering, antihypertensive and angiotensin converting enzyme inhibitor (ACE-I) or angiotensin 2 receptor blocker (ARB) drugs, and cohort membership were entered in the model as independent covariates.