326 Pre-morbid sleep disturbance and its association with stroke severity: results from the international INTERSTROKE study

Abstract

Abstract Background We have previously shown that disturbances in sleep to be associated with acute stroke, but their association with stroke severity is less certain. In the INTERSTROKE study, we evaluated the association of pre-morbid sleep disturbance with stroke severity and functional outcome in acute stroke patients. Methods INTERSTROKE was an international case–control study of first acute stroke. This analysis comprised cases who completed a standardised questionnaire concerning nine symptoms of sleep disturbance (sleep onset latency, duration and quality, nocturnal awakening, napping, snoring, snorting and breathing cessation) in the prior month (n = 2,361). Two indices were derived representing sleep disturbance (range 0–9) and Obstructive Sleep Apnoea (OSA; range 0–3) symptoms. The modified-Rankin score (m-RS) was used to measure stroke severity at initial assessment and functional outcome at 1-month follow-up. Severe stroke was defined as an m-RS of >3, and functional deterioration was defined as an increase in m-RS at 1-month. Logistic regression was used to estimate the magnitude of association between symptoms and stroke severity. Results The mean age of participants was 62.9 years, with 42% female, 80% diagnosed with ischaemic stroke and 17% reporting >5 sleep symptoms. On multivariable analysis, there was a graded association between increasing number of sleep disturbance symptoms and initially severe stroke (2–3: Odds Ratio [OR]:1.44; 95% CI [Confidence Interval]:1.07–1.94, 4–5: OR:1.66; CI:1.23–2.25, >5: OR:2.58; CI:1.83–3.66). Having >5 sleep disturbance symptoms was associated with a significant increased odds of functional deterioration at 1-month (OR:1.54; CI:1.01–2.34). A higher OSA score (2–3 vs 0–1) was also associated with a significant increased odds of initially severe stroke (OR:1.48; CI:1.20–1.83) but not functional deterioration at 1-month (OR:1.19; CI:0.93–1.52). Conclusion Symptoms of sleep disturbance were common and associated with an increased odds of severe stroke and functional deterioration at 1-month. Interventions to modify sleep disturbance may help prevent disabling stroke/improve functional outcome after stroke, and should be the subject of future research.