Diabetes Linked to Memory Problems in Older Adults
糖尿病与健忘症

A new study adds to growing evidence that the complications of diabetes may extend to the brain, causing declines in memory, attention and other cognitive skills.

有越来越多证据表明糖尿病并发症可能会扩大到脑部，造成大脑记忆力、注意力和其他认知功能的下降，而一项新的研究又为此提供了更多依据。

The new research showed that over the course of about a decade, elderly men and women with diabetes -- primarily Type 2, the form of the disease related to obesity and inactivity -- had greater drops in cognitive test scores than other people of a similar age. The more poorly managed their disease, the greater the deterioration in mental function. And the declines were seen not just in those with advanced diabetes. The researchers found that people who did not have diabetes at the start of the study but developed it later on also deteriorated to a greater extent than those without the disease.

这项新研究显示在过去十年里，患有糖尿病的老年人，主要是2型糖尿病患者，在认知测验中的得分下降幅度超过其他年龄相仿的老年人。2型糖尿病与肥胖和缺乏运动有关。患者对病情的控制越差，大脑功能退化就越严重。这种退化不仅出现在严重糖尿病的患者身上，研究人员发现，研究开始时未患糖尿病，而是后来患病的老年人，大脑功能减退的程度也比未患糖尿病者更严重。

"What we've shown is a clear association with diabetes and cognitive aging in terms of the slope and the rate of decline on these cognitive tests," said Dr. Kristine Yaffe, a professor of psychiatry and neurology at the University of California, San Francisco. "That's very powerful."

加州大学旧金山分校(University of California, San Francisco)精神病学及神经病学教授克里斯廷·亚菲博士(Dr. Kristine Yaffe)说：“我们展示出了糖尿病与老年人的认知衰老之间，存在清晰的联系。认知衰老是以认知测验得分下降的坡度和比率衡量的。这个结果非常有力。”
 
While correlation does not equal causation and the relationship between diabetes and brain health needs further study, the findings, if confirmed, could have significant implications for a large segment of the population. Nationwide, nearly a third of Americans over the age of 65, or roughly 11 million people, have diabetes. By 2034, about 15 million Medicare-eligible Americans are expected to have the disease.

尽管相关性并不等同于因果关系，糖尿病和大脑健康之间的关系还需要更进一步研究，然而如果这项发现得到证实，会对许多人产生深远的影响。在美国全国，65岁以上的人口中有三分之一患有糖尿病，总人数大约1100万人。到2034年，预计大约会有1500万享有医疗保险(Medicare)的美国人患有糖尿病。

Previous studies have shown that Type 2 diabetes correlates with a higher risk of Alzheimer's disease and dementia later in life. But how one leads to the other has not been well understood. While some scientists speculate that inflammation and vascular damage caused by chronically high blood sugar levels over many years is the culprit, findings from research have been inconsistent. And until now, little was known about the effect, if any, that newly diagnosed diabetes would have on cognitive function.

此前已有研究显示，2型糖尿病和若干年后患上阿尔茨海默氏症或痴呆的较高风险之间存在相关性。但两者之间的因果关系尚不明确。一些科学家推测，持续多年的慢性高血糖引起的炎症和血管损伤是罪魁祸首，但研究得出的结果并不完全一致。而且直到现在，我们对初诊糖尿病是否会给认知功能造成影响，以及会如何影响仍缺乏了解。

In the new study, published in Archives of Neurology, Dr. Yaffe and her colleagues relied on extensive data from the Health, Aging and Body Composition project, or Health ABC, a long-running study of white and black older adults living in Pittsburgh and Tennessee. The researchers looked at 3,069 people, many of them in their 70s. When the study began, 23 percent of the subjects had diabetes. And 5 percent were free of diabetes at the outset but went on to develop it later.

这项新研究发表在《神经病学档案》(Archives of Neurology)上。亚菲博士和她的同事是根据健康ABC项目中的大量数据进行的这项研究。健康ABC全称健康、衰老和身体成分(Health, Aging and Body Composition)项目，该项目长期对居住在匹兹堡和田纳西州的老年白人和黑人进行研究。 研究人员调查了3069人，其中很多人的年龄在70至79之间。研究开始时，23%的研究对象患有糖尿病。5%的研究对象在研究开始时没有糖尿病，但后来患病。

While the researchers did not distinguish between Type 1 and Type 2 diabetes, they said that given the average age of the subjects, about 74, most if not all had Type 2 diabetes.

尽管研究人员并未区分1型糖尿病和2型糖尿病，但他们说，考虑到研究对象的平均年龄已达74岁，其中绝大多数人都患有2型糖尿病。

Over the course of the research, the subjects were repeatedly given cognitive tests that looked at things like their memory, their coordination, dexterity and ability to concentrate, as well as their overall mental health. At the start of the study, those who already had diabetes had slightly lower baseline scores than the subjects who did not have the disease.

在整个研究过程中，研究对象反复接受认知测验，检查他们的记忆力、协调性、灵敏度和集中精力的能力，以及他们总体的心智健康。在研究开始时，已经患有糖尿病的研究对象的基准得分比非患者略低。

But nine years later, the gap in cognitive test scores had widened significantly between those with and without diabetes. The differences remained even after the researchers adjusted their results for the effects of age, race, sex and education. They also found that the subjects who were free of diabetes at the beginning of the study but developed it later on had scores that fell between those of the other two groups.

然而九年以后，糖尿病患者和非患者之间的测验得分差距显著扩大。即使研究人员根据年龄、种族、性别和教育程度的影响对结果进行调整后，差距依然存在。研究人员还发现，初期未患病，但后期成为患者的研究对象的测试结果处在开始即患病的对象和未患病对象之间。

The researchers then delved further by looking at the effect of poor glucose control. In this case, they took measures of something called glycosylated hemoglobin. Unlike traditional blood sugar tests, which provide a momentary snapshot of a person's glucose levels, glycosylated hemoglobin gives doctors a much broader picture, providing an idea of blood sugar management over the course of weeks. It is considered one of the best ways for doctors to assess the progress of diabetes treatment.

研究人员还对葡萄糖控制不佳的效果进行了更深入的研究。在这一研究中，他们对糖化血红蛋白水平进行了衡量。传统的血糖检查只反映人体内一瞬间的葡萄糖水平，与之不同的是，糖化血红蛋白检查则能对医生展示更全面的图景，反映数周时间里的血糖管理状况。糖化血红蛋白检查被认为是医生衡量糖尿病治疗进展的最好方法之一。

In the new study, higher measures of the compound, which indicate poorer control of blood glucose levels, were the best predictor of cognitive decline.

这次的新研究显示，较高的糖化血红蛋白水平能最好地预测认知能力的下降。糖化血红蛋白水平较高表明血糖的控制不佳。

The findings suggest that more aggressive approaches to managing and especially preventing diabetes in midlife or before may help stave off mental declines in large segments of the population. But Dr. Yaffe warned that doctors should be cautious about lowering blood sugar levels too far in elderly diabetics, since they are especially vulnerable to the effects of hypoglycemia.

研究结果显示，采取更积极的措施控制糖尿病，尤其避免在中年或之前患上糖尿病，能帮助大部分人避免脑力下降。不过亚菲博士警告医生们要保持谨慎，不要把老年糖尿病患者的血糖降得太低，因为他们尤其容易受到低血糖的影响。

"There's this idea that the better your glucose control, the better off you are in terms of trying to prevent complications of diabetes," she said. "But in older people it's a slippery slope. The elderly are more sensitive to hypoglycemia, they've got other medications that may interact, and they've got other conditions."

“人们有这样一种想法认为，葡萄糖控制得越好，就越容易防止糖尿病并发症。”她说，“但对老年人而言这是一种危险的做法。老年人对低血糖更敏感，要服用其他药品可能会产生相互作用，而且还患有其他病症。”

"When you lower their blood sugar levels too aggressively," she added, "you might do more harm than good."