Associations between Genetic Polymorphisms of Insulin-like Growth Factor Axis Genes and Risk for Age-Related Macular Degeneration

摘要: Age-related macular degeneration (AMD) is the major cause of irreversible vision loss in Western world,1 affecting approximately 15% elderly. At present, there no widely practicable treatment for AMD. It believed that AMD a multifactorial disease, and risk determined by multiple genetic environmental (including nutritional) factors.2,3 In recent studies, we observed link between glycemic index (GI) increased two American cohorts: Nutrition Vision Project (NVP) substudy Nurses' Health Study (NHS) Age-Related Eye Diseases (AREDS).4–6 Both studies indicate consuming diets higher blood glucose loads (i.e., with [GI]) associated otherwise healthy, nondiabetic individuals. The findings were also replicated Blue Mountain (BMES) cohort, Australia.7 The GI physiological measure “glycemic quality” carbohydrate-containing foods.8 Intake high-GI foods results rapid elevation postprandial levels relative to low-GI foods. clinical public health implication it can help people choose dietary (dGI) each subject was calculated as Σ (GIi × Wi)/W: weighted average values food item i (GIi) amount carbohydrate consumed from weight Wi/W.9 Thus, dGI be thought description pattern describes quality diet. Our evaluations indicated better correlate than total intake (quantity).4–6 analyses found association stronger individuals bilateral progression (more susceptible progression).6 Since suggests influence, hypothesized variants play epistatic or modifier role novel risk.6 Specifically, speculate gene–carbohydrate interactions are etiologic factors AMD.3 this study, investigated roles insulin-like growth factor (IGF)–related (often referred IGF axis) genes because nutrition has been shown affect circulating IGFs their responses10–12 several mechanistic have related these choroidal neovascularization, late-stage manifestation AMD.13–15 To test our hypothesis, used candidate gene approach evaluate whether polymorphisms specific IGF-axis alter