P030 Associations between objectively measured sleep and neurovascular coupling: preliminary results

Abstract Introduction Habitual poor sleep is linked to cerebrovascular disease. Impairments in neurovascular coupling (NVC) are thought to precede cerebrovascular disease, however, the effect of sleep on NVC is poorly understood. Methods Total sleep time (TST) and time in deep sleep (N3) were quantified during three home sleep assessments using an electroencephalography-based device (Somfit) in 35 participants (22 female, age 10.5–73.6 years). Blood velocity through the middle (MCAv) and posterior (PCAv) cerebral arteries was measured using transcranial Doppler ultrasound. Percent change in PCAv from eyes closed to peak PCAv during visual stimuli was taken to represent NVC. Hierarchical multiple regressions were used to explore the associations between NVC, age and sleep. Results Sleep duration ranged from 5.46–9.65 hours, and time in N3 from 22–200 minutes. Resting MCAv and PCAv ranged from 47–104 cm/s, and 28–65 cm/s respectively. NVC responses ranged from 6.8–44.4%. Age was associated with resting MCAv (R²=0.243, P=0.003), however, adding TST (F change=0.932) or time in N3 (F change=0.644) did not improve the model. Age was not associated with resting PCAv, and this did not change when TST or N3 sleep were added to the model (all R²<0.100, P>0.05). Similarly, no associations were found between NVC, age and TST/time in N3 (all R²<0.006, P>0.05. Conclusions Preliminary analyses reveal that resting MCAv decreases with age, while NVC does not. However, neither relationship was mediated by habitual sleep. Further data collection is being performed to capture a wider range of sleep patterns and ages.