Abstract
Purpose: :
Visual impairment (VI) is among most common causes of disability in the United States. About fourteen million individuals suffer from VI in the U.S. VI due to diabetic retinopathy (DR) affects the economic productivity of U.S. working-aged adults. Recent data from the National Health and Nutrition Examination Survey (NHANES) indicate approximately 32% of U.S. adults are obese. We investigated obesity’s association with VI using data extracted from continuous NHANES 2005-2008 data.
Methods: :
NHANES is an ongoing nationally representative survey of the US non-institutionalized population conducted by the National Center for Health Statistics, Centers for Disease Control and Prevention. Visual acuity and objective refraction/keratometric evaluation were measured for each eye using model ARK-760A. VI defined as presenting distance acuity of 20/50 or worse in the better-seeing eye that improved with objective refraction. Stratification methodological approach for diabetes and DR was employed in this study to explore the question of interest. Analyses were performed with use of SAS software (version 9.2; SAS Institute Inc, Cary, NC) to account for complex sampling design. Results with P<0.05 for 2-tailed tests were considered statistically significant.
Results: :
20497 individuals participated in NHANES 2005-2008, 7081 were >=40yrs, 557 NHANES participants with VI (weighted prevalence, 6.4%; 95%CI, 5.8%-7.0%) and 710 with DR. Age-adjusted prevalence of VI in persons was 3.1% (2.9-3.3). Prevalence of VI highest in persons ≥ 80yrs (21.9%), <high school (11.6%), below poverty line (10.4%), non-diabetics (10.3%) and undiagnosed diabetes (12.3%). Prevalence of DR highest in persons ≥ 80yrs (16.2%),non-Hispanic Blacks (15.9%), male (11.3%),<high school (13.9%),below poverty line (12.3%), current smokers (11.0%),obese (11.3%),no high BP (12.9%), and no hyperlipidemia (12.0%). In diabetic persons with DR, hyperlipidemia significant risk factor for VI (OR=4.6 (1.4-16.1) p-value=0.02). BMI not significant predictor of VI in non-diabetics (OR=1.0 (0.8-1.1), diabetics without DR (OR=1.0 (0.9-1.0) and diabetics with DR (OR=1.1 (1.0-1.2)
Conclusions: :
The results of this study are conclusive on available evidence that obesity does not raise the risk of visual impairment independent of its effect on diabetic retinopathy through diabetes.
Keywords: diabetic retinopathy • visual impairment: neuro-ophthalmological disease • diabetes