From the Division of Epidemiology (W.S., T.A., J.B.B.), Department of Family Medicine and Population Health, and Division of Adult Neurology (M.A.), Sleep Medicine, Vascular Neurology, Department of Neurology; and Department of Biostatistics (R.P.), Virginia Commonwealth University, School of Medicine, Richmond.
Neurology. 2023 Aug 1;101(5):e475-e488. doi: 10.1212/WNL.0000000000207449. Epub 2023 Jun 7.
Insomnia is a common condition affecting more than a third of the US population. However, the link between insomnia symptoms and stroke is understudied and the underlying mechanism remains unclear. This study aimed to investigate the relationship between insomnia symptoms and the incidence of stroke.
The Health and Retirement Study, a survey of Americans older than 50 years and their spouses, from 2002 to 2020 was used as the data source. Only those who were stroke-free at baseline were included in this study. The exposure variable was insomnia symptoms and was derived from self-reported sleep-related factors including difficulty initiating sleep, difficulty maintaining sleep, waking up too early, and nonrestorative sleep. Repeated-measures latent class analysis was used to identify insomnia trajectories over time. To investigate the relationship between insomnia symptoms and stroke events reported during the follow-up period, Cox proportional hazards regression models were used. Mediation analyses of comorbidities were performed using causal mediation within a counterfactual framework.
A total of 31,126 participants were included with a mean follow-up of 9 years. The mean age was 61 years (SD = 11.1) and 57% were females. Insomnia symptom trajectories remained constant over time. Compared with those with no insomnia symptoms, an increased risk of stroke was observed for those with insomnia symptom scores ranging from 1 to 4 and 5 to 8 (hazard ratio (HR) = 1.16, 95% confidence interval (CI) 1.02-1.33) and (HR = 1.51, 95% CI 1.29-1.77), respectively, indicating a dose-response relationship. The association was stronger in participants younger than 50 years (HR = 3.84, 95% CI 1.50-9.85) than in those aged 50 years and older (HR = 1.38, 95% CI 1.18-1.62), comparing those with insomnia symptoms ranging from 5 to 8 with those with no insomnia symptoms. This association was mediated by diabetes, hypertension, heart disease, and depression.
Insomnia symptoms were associated with an increased risk of stroke, especially in adults younger than 50 years, and the risk was mediated by certain comorbidities. Increased awareness and management of insomnia symptoms may contribute to the prevention of stroke occurrence.
失眠是一种常见病症，影响着超过三分之一的美国人口。然而，失眠症状与中风之间的关联研究较少，其潜在机制仍不清楚。本研究旨在探讨失眠症状与中风发病之间的关系。
本研究使用了 2002 年至 2020 年期间针对 50 岁以上美国人和其配偶进行的健康与退休研究（Health and Retirement Study）作为数据来源。仅纳入基线时无中风病史的人群。暴露变量为失眠症状，源自包括入睡困难、睡眠维持困难、早醒和睡眠质量差等与睡眠相关的因素的自我报告。采用重复测量潜在类别分析来识别随时间推移的失眠轨迹。为了研究随访期间报告的失眠症状与中风事件之间的关系，采用 Cox 比例风险回归模型。使用反事实框架内的因果中介分析对合并症进行中介分析。
共纳入 31126 名参与者，平均随访时间为 9 年。参与者的平均年龄为 61 岁（标准差=11.1），其中 57%为女性。失眠症状轨迹随时间保持不变。与无失眠症状的参与者相比，失眠症状评分为 1 至 4 分和 5 至 8 分的参与者发生中风的风险增加（风险比（HR）=1.16，95%置信区间（CI）1.02-1.33）和（HR=1.51，95%CI 1.29-1.77），呈剂量-反应关系。在年龄小于 50 岁的参与者中，这种关联更强（HR=3.84，95%CI 1.50-9.85），而在年龄为 50 岁及以上的参与者中，这种关联较弱（HR=1.38，95%CI 1.18-1.62），与失眠症状评分为 5 至 8 分的参与者相比，无失眠症状的参与者。这种关联由糖尿病、高血压、心脏病和抑郁症等合并症介导。
失眠症状与中风风险增加相关，尤其是在年龄小于 50 岁的成年人中，并且这种风险由某些合并症介导。提高对失眠症状的认识并加以管理，可能有助于预防中风的发生。
