晚上深度睡眠不够白天小睡多，都可能是阿兹海默症的症状

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.

医生提醒：让人确实能得到休息的、深度睡眠减少这一情况，对老年人而言，也许是阿兹海默症的一个早期标志。哪怕这时他们还未出现记忆力衰减的迹象。

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.

美国神经学家发现了这样的志愿者，他们的有效睡眠较少，体内有害物质tau的水平更高——阿兹海默症患者的大脑内就堆积着这种异常的蛋白质分子。

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.

早前的研究就发现，缺觉及阿兹海默症之间存在着关联。然而，“深度的”慢脑波睡眠才是最重要的，因为这恰恰是大脑加强记忆的时间段。

“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.

“关键在于，同tau相关联的并不是睡眠总量，慢波睡眠才反应睡眠质量。”华盛顿大学睡眠医学中心的布兰登•露茜博士说到。

“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增高异常的人，实际上却是晚上睡眠时间更长、白天小睡时间也更长的人。只不过，他们的睡眠质量不好。”

The study, published in the journal Neurology, recruited 119 people and 80 percent of them showed no sign of cognitive decline.

发表在期刊《神经学》上的这篇研究，研究过程中招募了119人，其中80%的人无认知功能衰退迹象。

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.

在志愿者睡觉时，使用脑动电流图监测他们的脑活动，然后测量tau及另一种异常蛋白质——淀粉样蛋白的水平。同时借助大脑扫描、脊椎穿刺来抽取脑脊髓液。

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.

阿兹海默症是最常见的痴呆症诱因。痴呆症，这一渐进式的集合名词指代的是记忆力及思考能力的丧失。这一病症目前已影响英国52万人。

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.

这项研究没法证明，睡眠减少是促成阿兹海默症的因素，还是说，它只是一个早期症状。如果能通过大量实验证实这种关联，那么睡眠模式方面的问题或许可以帮助我们较早发现征兆。

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.

鉴于目前并无可以阻止或减缓痴呆症的治疗方法，如果我们能在其症状显现前就监测到它。这对于辨认患者、测试未来药物而言，将是至关重要的一步。

“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.

“我们知道，睡眠与痴呆症之间有某种关联。但是就这种关联，还有太多需要研究。”阿兹海默症协会的研究带头人詹姆斯•皮克特博士这样说。

“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.”

“改变我们的睡眠习惯也许会减少发展为痴呆症的几率——现在这样说还为时尚早。但是确有积极证据表明，体力充沛、饮食健康可减少痴呆症几率。所以，放下薯片，选择苹果！尽可能多出门走走。”

翻译：everaining