晚上深度睡眠不夠白天小睡多，都可能是阿茲海默症的症狀
Doctors have warned that decreases in restful, deep sleep in old age could be an early sign of Alzheimer's disease before signs of memory impairment show.
醫生提醒：讓人確實能得到休息的、深度睡眠減少這一情況，對老年人而言，也許是阿茲海默症的一個早期標誌。哪怕這時他們還未出現記憶力衰減的跡象。
US neurologists found volunteers who had less restful sleep had higher levels of the toxic substance tau, an abnormal protein molecule found clumped together in the brains of patients with Alzheimer's.
美國神經學家發現了這樣的志願者，他們的有效睡眠較少，體內有害物質tau的水平更高——阿茲海默症患者的大腦內就堆積着這種異常的蛋白質分子。
Previous research has found links between sleeping less and Alzheimer's but it is “deep” slow-brainwave sleep that is thought to be most important as this is the period where the brain consolidates memories.
早前的研究就發現，缺覺及阿茲海默症之間存在着關聯。然而，“深度的”慢腦波睡眠纔是最重要的，因爲這恰恰是大腦加強記憶的時間段。
“The key is that it wasn't the total amount of sleep that was linked to tau, it was the slow-wave sleep, which reflects quality of sleep,” said Dr Brendan Lucey, director of the Washington University Sleep Medicine Centre.
“關鍵在於，同tau相關聯的並不是睡眠總量，慢波睡眠才反應睡眠質量。”華盛頓大學睡眠醫學中心的布蘭登•露茜博士說到。
“The people with increased tau pathology were actually sleeping more at night and napping more in the day, but they weren't getting as good quality sleep.”
“ tau增高異常的人，實際上卻是晚上睡眠時間更長、白天小睡時間也更長的人。只不過，他們的睡眠質量不好。”
The study, published in the journal Neurology, recruited 119 people and 80 percent of them showed no sign of cognitive decline.
發表在期刊《神經學》上的這篇研究，研究過程中招募了119人，其中80%的人無認知功能衰退跡象。
It used electroencephalograms to monitor the volunteers' brain activity while they slept then measured levels of tau, and another abnormal protein, amyloid beta, using brain scans and spinal taps to draw cerebrospinal fluid.
在志願者睡覺時，使用腦動電流圖監測他們的腦活動，然後測量tau及另一種異常蛋白質——澱粉樣蛋白的水平。同時藉助大腦掃描、脊椎穿刺來抽取腦脊髓液。
Alzheimer's disease is the most common cause of dementia – the progressive collective term for the loss of memory and thinking skills – and affects 520,000 people in the UK.
阿茲海默症是最常見的癡呆症誘因。癡呆症，這一漸進式的集合名詞指代的是記憶力及思考能力的喪失。這一病症目前已影響英國52萬人。
The research cannot tell whether reduced sleep is contributing to Alzheimer's, or if it's an early symptom, but if the link is verified in larger trials then questions about sleep patterns could help spot signs early.
這項研究沒法證明，睡眠減少是促成阿茲海默症的因素，還是說，它只是一個早期症狀。如果能通過大量實驗證實這種關聯，那麼睡眠模式方面的問題或許可以幫助我們較早發現徵兆。
While there are no treatments to stop or slow dementia, being able to detect it before symptoms manifest would be a vital step to identifying people for testing future drugs.
鑑於目前並無可以阻止或減緩癡呆症的治療方法，如果我們能在其症狀顯現前就監測到它。這對於辨認患者、測試未來藥物而言，將是至關重要的一步。
“We know there's a link between sleep and dementia, but there's still a lot to learn about this relationship,” said Dr James Pickett, head of research at the Alzheimer's Society.
“我們知道，睡眠與癡呆症之間有某種關聯。但是就這種關聯，還有太多需要研究。”阿茲海默症協會的研究帶頭人詹姆斯•皮克特博士這樣說。
“It's too soon to say if trying to change our sleep habits might affect our chances of developing dementia, but there's good evidence that being physically active and eating healthily can reduce the risk. So try to choose an apple over the packet of crisps, and get out as much as possible.”
“改變我們的睡眠習慣也許會減少發展爲癡呆症的機率——現在這樣說還爲時尚早。但是確有積極證據表明，體力充沛、飲食健康可減少癡呆症機率。所以，放下薯片，選擇蘋果！儘可能多出門走走。”
翻譯：everaining
