The impact of sleep quality and its change on the long-term risk of stroke in middle-aged and elderly people: Findings from the English Longitudinal Study of Ageing.

ABSTRACT

OBJECTIVE: This study focused on middle-aged and elderly adults (mean age ≥60 years) in England and aimed to evaluate the impact of sleep quality and change in sleep quality on the long-term risk of stroke. PATIENTS/METHODS: The current prospective study enrolled 6214 participants without stroke from wave 4 (2008-2009) of the English Longitudinal Study Aging (ELSA) dataset. From the ELSA questionnaires, sleep quality scores were calculated and used to evaluate the sleep quality of each participant. Cox proportional hazards regression models were used to assess the association between sleep status and stroke risk. Restricted cubic spline (RCS) was employed for the relationship between sleep quality score and the risk of stroke. RESULTS: During the 8-year follow-up, 130 (2.1%) cases of stroke were recorded. Participants with poor baseline sleep quality had a significantly higher long-term risk of stroke compared with those with good sleep quality (hazard ratio [HR] 2.37, 95% confidence intervals [CI] 1.44, 3.91). For the influence of change in sleep quality on stroke risk, worsened sleep quality was associated with a significant increase in the risk of stroke in the good (HR 2.08, 95% CI, 1.02, 4.26) and intermediate sleep quality groups (HR 2.15, 95% CI, 1.16, 3.98). Moreover, improved sleep quality decreased stroke risk among subjects with poor sleep quality (HR 0.31, 95% CI, 0.15, 0.61). CONCLUSIONS: Poor and worsened sleep quality is associated with an increased risk of stroke. Emphasis should be placed on improving sleep quality in middle-aged and elderly individuals.