睡眠模式的變化在阿爾茨海默病和其他癡呆症患者中很常見。他們可能在夜間經常醒來，發現很難重新入睡。這些睡眠問題被認為是由影響睡眠-覺醒週期的疾病引起的大腦變化引起的。女人躺在床上伸手拿鬧鐘。
研究表明，生命早期的睡眠模式可能會導致後期患癡呆症的風險。睡眠不足和睡眠時間長於平均水平都與患癡呆症的可能性更大有關。然而，很難確定這些睡眠變化是導致疾病還是僅僅反映了早期症狀。
許多關於睡眠和癡呆症風險的研究對參與者進行了不到十年的跟踪調查，重點關注 65 歲以上的人群。 Inserm 和倫敦大學學院的 Séverine Sabia 博士領導的一項研究調查了生命早期的睡眠模式可能會如何影響幾十年後癡呆症的發作。
該研究部分得到了 NIH 國家老齡化研究所 (NIA) 的支持。研究結果於 2021 年 4 月 20 日發表在 Nature Communications 上。
研究人員從 50 歲開始檢查了來自英國近 8,000 人的數據。參與者接受了各種各樣的評估，包括在 1985 年至 2016 年間六次被問及他們每晚睡了多少小時。為了評估這種自我報告的準確性，一些參與者佩戴了加速度計來客觀地測量睡眠時間。在研究過程中，521 名參與者被診斷出患有癡呆症，平均年齡為 77 歲。
數據分析表明，50 多歲和 60 多歲的人睡眠時間不超過 6 小時，以後患癡呆症的風險更大。與那些獲得正常睡眠（定義為 7 小時）的人相比，每晚休息較少的人被診斷出患有癡呆症的可能性要高 30%。
研究人員調整了他們的模型，以考慮其他已知會影響睡眠模式或癡呆風險的因素，包括吸煙、體力活動、體重指數以及糖尿病和心髒病等疾病。他們還將患有抑鬱症等精神疾病的人區分開來，這些疾病與睡眠障礙密切相關。
研究結果表明，中年期間睡眠時間短可能會增加晚年患癡呆症的風險。需要更多的研究來確認這種聯繫並了解根本原因。
“雖然我們無法確認睡眠不足實際上會增加患癡呆症的風險，但有很多原因可以解釋為什麼睡個好覺對大腦健康有益，”薩比亞說。
眾所周知，優質睡眠在註意力集中和學習以及情緒和整體健康方面發揮著重要作用。
From NIH Research Matters
Changes in sleep patterns are common in people with Alzheimer’s disease and other dementias. They may wake up often during the night and find it hard to get back to sleep. These sleep problems are thought to result from brain changes caused by the disease that affect the sleep-wake cycle.
Studies have suggested that sleep patterns earlier in life may contribute to later dementia risk. Both insufficient sleep and sleeping longer than average have been linked to a greater likelihood of developing dementia. However, it has been hard to determine whether these sleep changes contribute to the disease or simply reflect early symptoms.
Many of the studies on sleep and dementia risk have followed participants for less than a decade and focused on people over the age of 65. A study led by Dr. Séverine Sabia of Inserm and University College London examined how sleep patterns earlier in life may affect the onset of dementia decades later.
The study was supported in part by NIH’s National Institute on Aging (NIA). Findings appeared in Nature Communications on April 20, 2021.
The researchers examined data from nearly 8,000 people in Britain starting at age 50. Participants were assessed on a wide variety of measures, including being asked on six occasions between 1985 and 2016 how many hours they slept a night. To assess the accuracy of this self-reporting, some of the participants wore accelerometers to objectively measure sleep time. Over the course of the study, 521 participants were diagnosed with dementia, at an average age of 77.
Analysis of the data showed that people in their 50s and 60s getting six hours of sleep or less were at greater risk of developing dementia later. Compared to those getting normal sleep (defined as 7 hours), people getting less rest each night were 30% more likely to be diagnosed with dementia.
The researchers adjusted their model to account for other factors known to influence sleep patterns or dementia risk, including smoking, physical activity, body mass index, and medical conditions like diabetes and heart disease. They also separated out people with mental illnesses like depression, which are strongly linked to sleep disturbances.
The findings suggest that short sleep duration during midlife could increase the risk of developing dementia later in life. More research is needed to confirm this connection and understand the underlying reasons.
“While we cannot confirm that not sleeping enough actually increases the risk of dementia, there are plenty of reasons why a good night’s sleep might be good for brain health,” Sabia says.
Quality sleep is known to play an important role in concentration and learning, as well as mood and overall health.
—by Erin Bryant
This research was supported in part by NIA grants R01AG056477 and RF1AG062553.
Reference: Association of sleep duration in middle and old age with incidence of dementia. Sabia S, Fayosse A, Dumurgier J, van Hees VT, Paquet C, Sommerlad A, Kivimäki M, Dugravot A, Singh-Manoux A. Nat Commun. 2021 Apr 20;12(1):2289. doi: 10.1038/s41467-021-22354-2. PMID:33879784.