The association between bouted and non-bouted physical activity on retinopathy prevalence

Objective We evaluated the specific differential association between non-bouted, lifestyle physical activities (vs. structured exercise; i.e., bouted physical activity) on retinopathy prevalence among a national sample of the broader U.S. adult population. Methods Data from the 2005–2006 National Health and Nutrition Examination Survey (NHANES) was used to identify 1501 adults, between 40 and 85 years. Bouted and non-bouted physical activities were assessed using objective accelerometer monitoring. A 10-minute bout was defined as 10+ consecutive minutes above the moderate-to-vigorous physical activity (MVPA) cut-point, with the allowance of 1–2-minute interruption intervals. Non-bout MVPA was determined by the number of MVPA minutes not accrued in a bout. Participants were screened for non-proliferative retinopathy using Early Treatment Diabetic Retinopathy Study grading criteria, as well as objective retinal imaging assessments using the Canon Non-Mydriatic Retinal Camera CR6-45NM. Individuals were excluded if they had been diagnosed with coronary artery disease, congestive heart failure, heart attack or stroke. Results Participants with worse retinopathy engaged in less bouted and non-bouted physical activity, had a higher BMI and were more likely to have diabetes and hypertension. For every 1 min/day increase in non-bouted MVPA, participants had a 7% reduced odds of moderate-to-severe retinopathy compared to no retinopathy (OR = 0.93; 95% CI: 0.87–0.99; P = 0.04); results were similar in an unadjusted model (OR = 0.93; 95% CI: 0.89–0.97; P = 0.007). Bouted MVPA was not associated with retinopathy prevalence in the multivariate model. Conclusion In this nationally representative sample of adults, those who engaged in non-bouted physical activity had reduced odds of a diagnosis of moderate-to-severe retinopathy.