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 85years. 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 1min/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.