Long–term Dietary Carbohydrate Intake and Glycemic Index and Early Cortical and Nuclear Lens Opacities

Abstract

Abstract: : Purpose: In vitro and laboratory animal studies in vivo suggest that dietary carbohydrate intake plays a role in cataractogenesis. However, the association between quality and quantity of long–term dietary carbohydrate intake has never been systemically evaluated with respect to risk for developing early lens opacities. Objective: To test the hypothesis that long–term total carbohydrate intake and dietary glycemic index (GI) are associated with the prevalence of early cortical and nuclear opacities among non–diabetic subjects. Design: In 459 (908 eyes) non–diabetic middle–aged women, we related odds for cortical and nuclear lens opacities (quantified by the Lens Opacities Classification System III, LOCS III) to average energy–adjusted GI and total carbohydrate intake measured four times during a ten year period prior to recruitment into this study. Dietary intake information was gathered using semiquantitative food frequency questionnaires. Multiple logistic regression models, accounting for correlated data, were utilized to evaluate the hypothesis. Results: Women with a greater dietary carbohydrate intake had higher prevalence of cortical opacities (LOCS III > 1.0) than women with the lowest carbohydrate intake (p for trend = 0.05). The odds ratios in the multivariate–adjusted model for cortical opacities among women in the fourth and fifth quintile categories of dietary carbohydrate intake were 2.6 (95 % CI = 1.2 – 5.5) and 2.3 (95 % CI = 1.1 – 4.8), respectively, relative to women in the lowest category. Nuclear opacities (LOCS III > 2.5) were not associated with dietary carbohydrate intake; but showed a marginally significant positive association with GI (p for trend = 0.05) which was independent of total carbohydrate intake. Conclusions: These data suggest that the quantity of dietary carbohydrate intake is positively associated with risk for cortical lens opacities and that the quality (GI) may be an important determinant for nuclear lens opacification in middle–aged non–diabetic women.

Keywords: cataract • clinical (human) or epidemiologic studies: prevalence/incidence • aging