Prospective study of cataract extraction and risk of coronary heart disease in women

Oxidative damage to proteins in the human lens is believed to be important in the etiology of age-related cataract, Because free radical-mediated oxid ative damage to lipoproteins may accelerate atherosclerosis, the authors hy pothesized that the development of cataract might be a marker for such dama ge and therefore might be associated with future risk of coronary heart dis ease (CHD). The authors followed 60,657 women aged 45-63 years and without known coronary disease, stroke, or cancer in 1984. During 10 years of follo w-up (674,283 person-years), the authors documented 887 incident cases of C HD and 2,322 deaths. After adjustment for age, smoking, and other coronary risk factors, cataract extraction was significantly associated with higher risk of CHD (relative risk (RR) = 1.88, 95% confidence interval (CI): 1.41, 2.50) for total CHD, 2.44 (95% CI: 1.54, 3.89) for fatal CHD, and 1.63 (95 % CI: 1.14, 2.34) for nonfatal myocardial infarction). The positive associa tion between cataract extraction and total CHD was stronger among women wit h a history of diabetes (RR = 2.80, 95% CI: 1.77, 4.42) than among those wi thout reported diabetes (RR = 1.51, 95 percent CI: 1.04, 2.18). In multivar iate analyses; cataract extraction was associated with significantly increa sed overall mortality (RR = 1.37, 95 percent CI: 1.13, 1.66), which was ent irely explained by the increased mortality from cardiovascular disease (RR = 1.84, 95% CI: 1.29, 2.64). These findings are compatible with current hyp otheses relating oxidative damage and tissue aging to the development of ca taract and CHD.