RETINOPATHY IN AFRICAN-AMERICANS AND WHITES WITH INSULIN-DEPENDENT DIABETES-MELLITUS

Background: The development and progression of dia betic retinopathy i n African Americans with insulin-dependent diabetes mellitus is not kn own. Methods: Two hundred subjects with insulin-dependent diabetes mel litus with duration of diabetes 16 years or less at first visit were s tudied; 58 were African Americans and 142 were whites. All had gradabl e stereoscopic color fundus photographs (seven standard fields) from a t least two visits (mean time between first and second visit was 4.1 y ears). Subjects with hemoglobinopathy or proliferative retinopathy or subjects who had evidence of treatment for proliferative retinopathy a t first visit were excluded. Masked grading of photographs was conduct ed using the modified Airlie House classification scheme. Results: Afr ican Americans were older, heavier, had higher systolic blood pressure (all P<.05), and margin-ally higher hemoglobin A(1) (HbA(1)) values ( P=.06) than the whites at first visit. African Americans had a lower r ate of two steps or more progression from preexistent retinopathy (19% ) than whites (43%). Progression to proliferative retinopathy or treat ment was similar by race. Multivariate analysis predicting development or progression of retinopathy, while controlling for length of follow up, found higher HbA(1) (odds ratio [OR]=2.15), longer duration of ins ulin-dependent diabetes mellitus (OR=1.63), higher serum creatinine co ncentration (OR=1.55,), and white race (OR=2.62) to be independent ris k factors. Conclusions: These data suggest a previously unsuspected re duction in the adjusted risk for development and progression of retino pathy in African Americans. The reason for this apparently reduced ris k are not known.