Sleep, self‐reported ocular health, and cognition in the Hispanic Community Health Study/Study of Latinos (HCHS/SOL) and SOL‐Investigation of Neurocognitive Aging (SOL‐INCA)

Abstract

Abstract/ProposalBackgroundVisually impaired individuals may experience increased frequency of sleep/wake disorders, fragmented sleep, insomnia, and short sleep duration. Visual impairment and sleep disorders can have downstream effects on cognitive functioning.MethodSample included n = 590 (unweighted) HCHS/SOL Miami Field Center participants ages 45‐74 at baseline who returned for cognitive examination on average 7‐years later (SOL‐INCA). Participants completed validated ocular (National Eye Institute Visual Functioning Questionnaire; NEI‐VFQ), validated sleep questionnaires for sleepiness, insomnia, sleep duration and objective measures of sleep apnea visit‐1 (2008‐2011). They also completed a battery of neurocognitive tests for verbal episodic learning and memory (Brief Spanish English Verbal Learning Test), verbal fluency (Controlled Oral Word Association), processing speed and executive function (Digit Symbol Substitution) at visit‐1 and at SOL‐INCA. Two additional measures of processing speed/executive functioning were added at SOL‐INCA(Trails‐A, ‐B). We examined global cognitive performance and change using a regression‐based reliable change index, adjusting for the time lapse between visit 1 and SOL‐INCA (all measured in z‐score units). We used regression models to test whether (1) participants with sleep disorders have an increased risk for visual impairment, (2a) ocular health is associated with worse baseline and average 7‐years cognitive function and/or cognitive decline, and (2b) sleep attenuates any of these associations.ResultSleepiness (β = 0.04; p<0.01) and insomnia (β = 0.03; p<0.001) were linked to worse ocular health, and the associations were robust to adjustment for sociodemographic characteristics, acculturation, behavioral risk measures, and health conditions. Worse ocular health was linked to lower global cognitive function at baseline (β = ‐0.14; p<0.001) and on average 7‐years later (β = ‐0.16; p<0.01). The associations were consistent across all considered cognitive domains and robust to demographic adjustments. Ocular health was also associated with a change in verbal fluency (β = ‐0.17; p<0.05), but no change was observed in other cognitive domains. Sleep disorders did not attenuate any of the reported associations.ConclusionSelf‐reported ocular health was independently associated with worse language, memory, and executive function and predicted 7‐year cognitive decline in the language domain.