Jesse L Parker,1 Andrew Vakulin,1,2 Yohannes Adama Melaku,1 Gary A Wittert,3,4 Sean A Martin,3,4 Angela L D’Rozario,2,5 Peter G Catcheside,1 Bastien Lechat,1 Barbara Toson,6 Alison J Teare,1 Sarah L Appleton,1,4,* Robert J Adams1,4,7,* 1Flinders Health and Medical Research Institute, Adelaide Institute for Sleep Health, Flinders University, Adelaide, SA, Australia; 2CIRUS, Centre for Sleep and Chronobiology, Woolcock Institute of Medical Research, University of Sydney, Sydney, NSW, Australia; 3Freemasons Centre for Male Health and Wellbeing, Adelaide Medical School, University of Adelaide, Adelaide, SA, Australia; 4South Australian Health and Medical Research Institute, Adelaide, SA, Australia; 5The University of Sydney, Faculty of Science, School of Psychology, Sydney, NSW, Australia; 6College of Medicine and Public Health, Flinders University, Adelaide, SA, Australia; 7Respiratory and Sleep Services, Southern Adelaide Local Health Network, Adelaide, SA, Australia*These authors contributed equally to this workCorrespondence: Jesse L Parker, Flinders Health and Medical Research Institute, Adelaide Institute for Sleep Health, Mark Oliphant Building, Flinders University, 5 Laffer Drive, Bedford Park, Adelaide, SA, 5042, Australia, Tel +61 0420431392, Email park0769@flinders.edu.auPurpose: Prospective studies examining associations between baseline sleep microarchitecture and future cognitive function recruited from small samples with predominantly short follow-up. This study examined sleep microarchitecture predictors of cognitive function (visual attention, processing speed, and executive function) after 8 years in community-dwelling men.Patients and Methods: Florey Adelaide Male Ageing Study participants (n=477) underwent home-based polysomnography (2010– 2011), with 157 completing baseline (2007– 2010) and follow-up (2018– 2019) cognitive assessments (trail-making tests A [TMT-A] and B [TMT-B] and the standardized mini-mental state examination [SMMSE]). Whole-night F4-M1 sleep EEG recordings were processed following artifact exclusion, and quantitative EEG characteristics were obtained using validated algorithms. Associations between baseline sleep microarchitecture and future cognitive function (visual attention, processing speed, and executive function) were examined using linear regression models adjusted for baseline obstructive sleep apnoea, other risk factors, and cognition.Results: The final sample included men aged (mean [SD]) 58.9 (8.9) years at baseline, overweight (BMI 28.5 [4.2] kg/m2), and well educated (75.2% ≥Bachelor, Certificate, or Trade), with majorly normal baseline cognition. Median (IQR) follow-up was 8.3 (7.9, 8.6) years. In adjusted analyses, NREM and REM sleep EEG spectral power was not associated with TMT-A, TMT-B, or SMMSE performance (all p> 0.05). A significant association of higher N3 sleep fast spindle density with worse TMT-B performance (B=1.06, 95% CI [0.13, 2.00], p=0.026) did not persist following adjustment for baseline TMT-B performance.Conclusion: In this sample of community-dwelling men, sleep microarchitecture was not independently associated with visual attention, processing speed, or executive function after 8 years.Keywords: quantitative EEG, spindles, attention, processing speed, executive function