Influence of Diabetes and Cardiovascular Disease on the Long-Term Incidence of Cataract: The Blue Mountains Eye Study

Abstract

Purpose: To assess associations between diabetes and selected cardiovascular risk factors and long-term incident cataract and cataract surgery. Methods: A cohort of initially 3654 elderly Australians were followed over a period of 10 years. Questionnaires ascertained relevant history and fasting blood samples were taken. Impaired fasting glucose (IFG) and metabolic syndrome were defined using World Health Organization criteria. Discrete logistic models were used to assess risk of incident cataract. Results: After controlling for age, sex, and other factors, baseline diabetes predicted nuclear cataract (relative risk, RR, 1.64; 95% confidence interval (CI), 1.02–2.64) and IFG predicted cortical cataract (RR, 2.01; CI, 1.20–3.36). Each standard deviation (SD) increase in glucose was positively associated with cortical cataract (RR, 1.13; CI, 1.01–1.27). Higher body mass index (BMI) was positively associated with posterior subcapsular cataract (RR per SD, 1.20; CI, 1.03–1.41). Persons using anti-hypertensive medication had a higher incidence of cataract surgery (RR, 1.61; CI, 1.18–2.20). Metabolic syndrome was associated with an increased risk of all 3 cataract subtypes. Few other significant associations were found between cardiovascular disease, cardiovascular risk factors, and incident cataract or cataract surgery. Conclusions: We confirmed diabetes as a risk factor for age-related cataract and IFG as a possible risk factor for cortical cataract. BMI and hypertension were also related to incident cataract. Overall, few associations were found between cardiovascular risk factors and long-term incident cataract. A cluster of metabolic abnormalities attributable to insulin resistance appears more likely to contribute to cataract formation than any individual cardiovascular risk factor alone.