The association of alcohol consumption with the incidence and progression of diabetic retinopathy.

PURPOSE: To investigate the association of alcohol consumption with the incidence and progression of diabetic retinopathy.
METHODS: The population consisted of a cohort of adult younger-onset (diagnosis received before 30 years of age and taking insulin, n = 439) and older-onset (diagnosis received after 30 years of age, n = 478) persons with diabetes examined from 1984 to 1986 and again from 1990 to 1992. The outcomes were incidence of retinopathy, progression, and progression to proliferative retinopathy. Retinopathy was determined by grading of stereoscopic color fundus photographs. Alcohol consumption was determined by questionnaire and summarized as average or recent consumption. The proportion of heavier drinkers was small, 6% of younger-onset and 4% of older-onset persons.
RESULTS: In the younger-onset group, progression of retinopathy occurred in 62%, 51%, 61%, and 71% of nondrinkers, light, moderate, and heavier drinkers, respectively, based on average intake (P = 0.28). Based on recent intake, 55%, 46%, 63%, and 69% of nondrinkers, light, moderate, and heavier drinkers, respectively, progressed (P = 0.10). A similar trend is seen for incidence of retinopathy, but the sample sizes are small. No association is seen with progression to proliferative diabetic retinopathy. After controlling for age, sex, and glycemia in a logistic regression model, alcohol intake is not associated with progression of retinopathy. In the older-onset group, alcohol intake is not related to the incidence or progression of retinopathy.
CONCLUSION: Alcohol consumption in moderation (< or = 1 oz/day) does not appear to affect the occurrence of diabetic retinopathy.