Abstract
Abstract: :
Purpose: We previously reported an increased risk (RR 2.64) of progression of AMD among current female cigarette smokers and similar non-significant risks were seen for males (Cote J, ARVO Abstract #4391, 2002). We now report the impact of overall obesity and abdominal adiposity as assessed by body mass index (BMI) and waist-hip (W/H) ratio. Data were obtained from our Progression of Age-Related Macular Degeneration Study, a longitudinal study designed to identify risk and protective factors for the onset and progression of advanced AMD. Methods: A total of 254 individuals were included in these prospective analyses, 102 males and 152 females. All participants were at least 60 years of age at baseline, with no reported history of cancer. Average follow-up time was 4.8 years. A five-grade classification scale of AMD was used. Progression of AMD was defined as either eye progressing from a grade of less than 4 (extensive small or large drusen) to grades 4 (geographic atrophy) and 5 (neovascular AMD), or progressing from grade 4 to grade 5, at any follow-up visit. We adjusted for age, sex, education, systolic blood pressure, smoking status (current, past, never), baseline AMD grade, baseline dietary calorie-adjusted carotenoid intake, calories (continuous), and alcohol intake (continuous). Cox proportional models were used to assess increased risk of advanced AMD for men and women according to BMI based on measurements of height and weight and W/H measurements. Results: Higher BMI significantly increased risk of progression of AMD, [relative risk (RR) 2.4, 95% Confidence interval (CI) 1.3,4.6, p = 0.005] for BMI ≥30 and [RR 2.3, 95% CI 1.3,4.1, p=0.005] for BMI 25-29, compared with the lowest level (<25). The test for trend for BMI was also significant, p-value = 0.006. Current increased W/H ratio was also a significant predictor of AMD progression. The highest tertile (≥1 for men and ≥0.897 for women) had a 2-fold increased risk of progression of AMD [RR 2.0, 95%CI 1.1,3.5, p=0.016] compared to the lowest tertile (<.947 for men and <.848 for women) and a smaller non-significant effect was seen for the middle tertile [RR 1.3, 95%CI 0.7,2.3, p=0.38] versus the lowest tertile. The test for trend for W/H ratio was significant, p= 0.012. Conclusions: Obesity, as measured by BMI and W/H ratio, is independently related to the progression of AMD in this study. These results provide new information regarding modifiable factors associated with progression of AMD and add insights regarding the management of AMD.
Keywords: age-related macular degeneration • clinical (human) or epidemiologic studies: ris