title: Effect of physical activity on mortality risk among Americans with retinopathy.
abstract: BACKGROUND
  Previous work demonstrates that retinopathy is associated with increased mortality risk, with physical activity inversely associated with retinopathy and all-cause mortality. However, no study has evaluated the effects of physical activity on mortality among those with existing retinopathy, which was this study's purpose.
  
  
  METHODS
  Data from the 2005-2006 National Health and Nutrition Examination Survey were utilized, with follow-up through 2011. Retinopathy was objectively-measured using the Canon Non-Mydriatic Retinal Camera CR6-45NM. Physical activity was objectively-measured via up to 7 days of accelerometry assessment.
  
  
  RESULTS
  Six-hundred and seventy one adults (40-85 years) with complete data on the study variables constituted the analytic sample. During the follow-up period, 91 deaths occurred. In the sample, 35 886 person-months occurred with a mortality incidence rate of 2.5 deaths per1000 person-months. Among participants with mild retinopathy, those who met physical activity guidelines at baseline had a 63% reduced risk of all-cause mortality (HR adjusted = 0.37; 95% CI:0.18-0.75; P = 0.007). Notably, physical activity was not associated with mortality risk among those with moderate/severe retinopathy (HR adjusted = 0.371.72; 95% CI: 0.62-4.76; P = 0.27).
  
  
  CONCLUSIONS
  Physical activity is associated with reduced mortality risk among those with mild retinopathy, but not among those with moderate/severe retinopathy.
authors: Jackson Heart Study Vanguard Center of Oxford, Physical Activity Epidemiology Laboratory, Center for Health Behavior Research, Department of Health, Exercise Science and Recreation Management, The University of Mississippi, University, MS 38677, USA.
authors: Paul D
authors: PD
authors: Loprinzi
keywords: Accelerometry; Epidemiology; Physical activity; Vision