Abstract
Purpose::
The epidemiological and clinical evidence on selenium’s protective role as an anti-oxidant in the development of age-related eye diseases have been inconclusive. The present cross-sectional study examines the relationship between supplement intake of selenium and severe cataract in older ambulatory women who participated in the Study of Osteoporotic Fractures (SOF).
Methods::
Lens photographs from a random sample of women at the year 10 (visit 6) clinic visits in SOF in 1997-9 were graded. Cataract status was independently assessed by two masked, trained graders using the Age-Related Eye Disease Study (AREDS) lens opacity grading system, adapted from Wisconsin lens opacity grading protocol. The discrepancies between two graders were adjudicated. Status of aphakia/IOL was also determined for all women with gradable external and/or lens photographs. Daily intake of selenium from supplements was calculated based on the Block Food Frequency Questionnaires (FFQ). Relationship between the supplement use of selenium and IOL in at least one eye was evaluated using the Fisher’s exact test and further analyzed using logistic regression models, adjusted for potential confounders: study site, age, race, smoking status, alcohol consumption, body mass index (BMI), education, walk for exercise, self-rated health status, and the presence of diabetes, hypertension, and age-related macular degeneration.
Results::
Among 1,274 women in the random sample, 1,190 (93%) had known lens status and completed FFQ. 479 (40%) women had IOL in at least one eye. 35 (3%) women took daily selenium from supplements, and they were less likely to have IOL compared with those who did not take selenium from supplements in the adjusted analysis (odds ratio [OR]=0.44, confidence interval [CI]=0.20-0.99, p=0.047).
Conclusions::
Our finding suggests that higher intake of selenium may be associated with decreased risk for progression to severe cataract in older women. This is consistent with the anti-oxidative effect of selenium in delaying cataract development, as demonstrated in previously published studies on animal models and epidemiologic data.
Keywords: cataract • antioxidants • clinical (human) or epidemiologic studies: risk factor assessment