Age-Related Maculopathy (ARM) in a Randomized Trial of Beta-Carotene in Men

Abstract

Abstract: : Purpose: To evaluate whether beta-carotene affects ARM in a randomized trial of apparently healthy U.S. male physicians.Methods: The Physicians’ Health Study I was a randomized, double-blind, placebo-controlled trial of beta-carotene (50 mg. every other day) and low-dose aspirin conducted among 22,071 U.S. male physicians age 40 to 84 years in 1982. The beta carotene component ended as scheduled on December 31, 1995, at which time compliance was 78 percent in the group assigned beta carotene, and only 6% of those assigned placebo reported using beta-carotene or vitamin A supplements. A total of 21,216 participants did not report ARM at baseline, were followed up for at least 7 years, and were included in this analysis. Main outcome measures were total ARM, defined as a self-report confirmed by medical record evidence of an initial diagnosis subsequent to randomization, and ARM with vision loss, defined as total ARM with vision to 20/30 or worse attributable to this condition. Results: During an average of 12 years of treatment and follow-up, a total of 532 cases of ARM were confirmed, including 332 cases responsible for vision loss to 20/30 or worse. For the endpoint of total ARM, there were 261 cases in the beta-carotene group and 271 in the placebo group (relative risk [RR], 0.97; 95% confidence interval [CI], 0.82-1.15). For ARM with vision loss, there were 160 cases in the beta-carotene group and 172 in the placebo group (RR, 0.95; 95% CI, 0.76-1.17). Conclusions: These randomized trial data from a large population of apparently healthy men indicate that 12 years of beta-carotene supplementation has no appreciable effect on ARM during the treatment period. The width of the 95% CI suggests that this large-scale randomized trial can reliably exclude benefit or harm greater than 15-25%.

Keywords: age-related macular degeneration • clinical (human) or epidemiologic studies: tre • antioxidants