O070 Longitudinal associations of sleep microarchitecture with future cognitive function in middle-aged and older men from a community-based cohort study

Abstract

Abstract Study objectives Prospective studies examining associations of sleep microarchitecture with future cognitive function predominantly recruited from small samples with relatively short follow-up. Therefore, this study examined sleep microarchitecture predictors of cognitive function (visual attention, processing speed, and executive function) after 8–10 years in community-dwelling middle-aged and older men. Methods Of 433 Florey Adelaide Male Ageing Study participants who underwent home-based polysomnography (2010–2011), 157 completed baseline and follow-up cognitive testing. Whole-night F4-M1 sleep EEG recordings were processed following artefact exclusion, and quantitative EEG features obtained using validated algorithms. Trail-making tests A (TMT-A) and B (TMT-B) were administered at baseline (2007–2010) and follow-up (2018–2019) examinations. Linear regression models were adjusted for baseline obstructive sleep apnea, demographic, biomedical, and behavioural factors, and cognitive performance. Results At baseline, participants were aged mean (SD) 58.9 (8.9) years with normal cognition. In unadjusted models only, lower REM sleep delta and higher alpha power were associated with worse TMT-A performance at follow-up (delta, B= -0.02, 95% CI [-0.04, -0.001], p=0.042; alpha, B=0.08, 95% CI [0.01, 0.15], p=0.024). Lower overall and slow sleep spindle density in N2 and N3 were associated with worse TMT-A performance at follow-up (all p<0.05). The association of higher fast spindle density in N3 with worse TMT-B performance (B =1.06, 95% CI [0.13, 2.00], p=0.026) was not significant after adjustment for baseline cognition. Conclusions In this sample of community-dwelling middle-aged and older men with normal baseline cognition, sleep microarchitecture parameters were not independently associated with cognitive function after 8–10 years.