Abstract
Purpose:
Cardiovascular disease (CVD) risk factors may contribute to changes in contrast sensitivity (CS) with aging. The purpose of this paper was to evaluate associations between CVD risk factors and the five-year incidence of impaired CS in middle-aged adults.
Methods:
At the baseline examination of the Beaver Dam Offspring Study (BOSS), participants were 21-84 yrs of age (n=3285; 2005-2008). CS was measured with a standardized protocol using the Pelli-Robson chart at the baseline and five-yr follow-up examinations (2010-2012). At baseline, carotid artery ultrasound was used to measure atherosclerosis (mean carotid artery intima-media thickness (IMT) and the number of sites with plaque (range 0-6)), and serum interleukin-6 (IL6) and intercellular adhesion molecule (ICAM1) were measured. Additional CVD risk factors (smoking, hypertension, diabetes, weight, alcohol consumption, etc.) also were measured. Cataract and age-related macular degeneration (AMD) were assessed by grading digital images. Impaired CS was defined as a score of <1.55 log units in the better eye. Analyses excluded people with AMD, cataract or impaired CS at baseline.
Results:
In preliminary analyses of 1708 participants without impaired CS at baseline, the incidence of impaired CS was 17.6%. In multivariable analyses, age (Odds Ratio (OR)=1.26 per five years, 95%Confidence Interval (CI) =1.15,1.37), IMT (OR=1.26 per 0.1 mm, 95%CI=1.13,1.40) and IL6 (OR= 1.65, 95%CI=1.24,2.18; third tertile vs other two) were associated with the risk of impaired CS. Plaque count was also associated with the incidence of impaired CS (adjusted OR= 1.39, 95% CI=1.19,1.61). Including other CVD risk factors in these models did not alter these associations.
Conclusions:
These data suggest that atherosclerosis and inflammation are independently associated with changes in contrast sensitivity. Vascular damage and potential direct effects of inflammation may be involved in changes in neural function associated with aging and contribute to declines in vision.
Keywords: 464 clinical (human) or epidemiologic studies: risk factor assessment •
413 aging •
478 contrast sensitivity