A LONGITUDINAL-STUDY OF BODY-MASS INDEX AND LENS OPACITIES - THE FRAMINGHAM STUDIES

Objective: The purpose of the study was to determine whether body mass index (BMI) is an independent risk factor for the development of nucl ear, cortical, or posterior subcapsular lens opacities. Design: A coho rt study. Participants and Methods: Eye examinations were conducted on surviving members of the Framingham Heart Study Cohort from 1973 to 1 975 (Framingham Eye Study I) and again from 1986 to 1989 (Framingham E ye Study II). Data from the Framingham Heart Study, including weight m easurements collected biennially from 1948, were used to examine assoc iations between BMI (mean BMI across examinations, slope of BMI over t ime, and fluctuations in BMI) and the development of lens opacities. T his analysis included 714 individuals, aged 52-80 years, who were free of lens opacities at the first eye examination. Main Outcome Measures : Development of nuclear, cortical, and posterior subcapsular lens opa cities. Results: A total of 444 persons developed lens opacities durin g the approximately 13 years between eye examinations. In logistic reg ression analyses that controlled for age, sex, education, diabetes, an d smoking, the risk of developing cortical opacity increased with high er BMI at the time of the first eye examination (P = 0.002), Risk of c ortical opacities also increased, at a borderline level of significanc e, with higher average BMI (P = 0.09) across examinations and increasi ng BMI levels over time (P = 0.10). There was a strong association bet ween increasing BMI over time and the development of posterior subcaps ular lens opacities (P = 0.002). No associations were found for nuclea r lens opacities. Conclusions: Although the mechanism explaining the a ssociation is unclear, these findings suggest that BMI, a potentially modifiable characteristic, is associated with the development of corti cal and posterior subcapsular lens opacities.