Abstract
Purpose: :
Studies of visually impaired adults have shown that visual impairment is associated with increased mortality, increased length of hospital stay, and risk of falls. How visual impairment impacts these events is not well understood and may be an effect of reduced physical activity. Visual impairment has been associated with reduction in a variety of daily living activities. The purpose of this project is to evaluate the relationship of vision reduction to caloric expenditure.
Methods: :
The current study consists of 955 subjects who had visual acuity measured as part of the UAB Study of Aging (UABSOA). The UABSOA is a community–based longitudinal study of 1000 subjects enrolled from Medicare beneficiary lists. Participants are drawn from 3 rural and 2 urban counties in Alabama. The population is 50.8% white, 50.5% male, with 51% living in rural communities. Measurements include an interview based questionnaire and in–home performance based testing. Visual acuity was measured in home using an illuminated ETDRS chart. Kilocalorie expenditure per week was calculated from the 15 item Leisure Time Physical Activity Questionnaire. This questionnaire asks about specific activities performed and over what time frame for a two week period.
Results: :
Kcal expenditure was negatively correlated with increasing acuity (rho –.16, p <.001), self report of poor vision (rho –.107,p=.001) and self report of glaucoma (rho –.063, p=.048). In a multivariate model controlling for age, gender, race, body mass index, geriatric depression scale score, MMSE score, Charlson index, and number of medications taken, visual acuity remains a negatively associated independent predictor of kilocalorie expenditure(p=.008).
Conclusions: :
Reduced visual acuity is associated with lower levels of caloric expenditure as estimated by the Leisure Time Physical Activity Questionnaire. These results suggest that visual impairment among older adults is associated with an overall reduction in total physical activity.
Keywords: visual acuity • clinical (human) or epidemiologic studies: outcomes/complications • clinical (human) or epidemiologic studies: risk factor assessment