Relation between intake of vitamins C and E and risk of diabetic retinopathy in the Atherosclerosis Risk in Communities Study.
BACKGROUND
The potential protective effect of vitamins C and E against the development of diabetic retinopathy has not been thoroughly evaluated in epidemiologic studies.


OBJECTIVE
The objective was to study the association between prevalent diabetic retinopathy and intake of vitamins C and E in participants of the Atherosclerosis Risk in Communities Study.


METHODS
A total of 1353 subjects with type 2 diabetes diagnosed between 1993 and 1995 or before were included. Nutrient intake was assessed with a food-frequency and supplement questionnaire administered between 1987-1989 and 1993-1995. Prevalent retinopathy (n = 224) was determined in 1993-1995 from graded fundus photographs.


RESULTS
No association of retinopathy with intake of vitamin C or E from food alone or from food and supplements combined was observed. The odds ratios and 95% CIs for retinopathy for quartile 4 compared with quartile 1 of vitamins C and E intakes from food and supplements combined were 1.1 (0.7, 1.9) and 1.3 (0.8, 2.2), respectively, after adjustment for diabetes treatment and serum glucose. There was a significant interaction of the observed relations with serum glucose concentration (P < 0.05). Additionally, a decreased odds of retinopathy was found among users (reported use > or =3 y before 1993-1995) of vitamin C or E supplements or multisupplements compared with reported use of no supplements: 0.5 (0.3, 0.8), 0.5 (0.2, 0.8), and 0.4 (0.2, 0.9), respectively.


CONCLUSIONS
No significant overall associations were observed between risk of retinopathy and intake of major dietary antioxidants. The observed association between risk of retinopathy and supplement use may reflect nondietary factors or a possible benefit of supplementation.
Millen
Amy E
AE
Department of Ophthalmology and Visual Sciences, University of Wisconsin Medical School, 610 North Walnut Street, 405 WARF Building, Madison, WI 53705-2197, USA.
Klein
Ronald
R
Folsom
Aaron R
AR
Stevens
June
J
Palta
Mari
M
Mares
Julie A
JA
D000975:Antioxidants / Q000008:administration & dosage* / Q000378:metabolism; D001161:Arteriosclerosis / Q000453:epidemiology* / Q000517:prevention & control; D001205:Ascorbic Acid / Q000008:administration & dosage* / Q000097:blood; D003924:Diabetes Mellitus, Type 2 / Q000150:complications*; D003930:Diabetic Retinopathy / Q000453:epidemiology* / Q000517:prevention & control; D004032:Diet; D019587:Dietary Supplements; D016021:Epidemiologic Studies; D005260:Female; D006306:Health Surveys; D006801:Humans; D008297:Male; D008875:Middle Aged; D009749:Nutrition Surveys; D016017:Odds Ratio; D015995:Prevalence; D012307:Risk Factors; D011795:Surveys and Questionnaires; D014810:Vitamin E / Q000008:administration & dosage* / Q000097:blood
D000975:Antioxidants; D014810:Vitamin E; D001205:Ascorbic Acid