Endocrinology Unit, Centre for Cardiovascular Science, Queen's Medical Research Institute, University of Edinburgh, Edinburgh, UK.
Diabetes Care. 2010 Apr;33(4):714-20. doi: 10.2337/dc09-1796. Epub 2010 Jan 22.
People with type 2 diabetes are at increased risk of cognitive impairment but the mechanism is uncertain. Elevated glucocorticoid levels in rodents and humans are associated with cognitive impairment. We aimed to determine whether fasting cortisol levels are associated with cognitive ability and estimated lifetime cognitive change in an elderly population with type 2 diabetes.
This was a cross-sectional study of 1,066 men and women aged 60-75 years with type 2 diabetes, living in Lothian, Scotland (the Edinburgh Type 2 Diabetes Study). Cognitive abilities in memory, nonverbal reasoning, information processing speed, executive function, and mental flexibility were tested, and a general cognitive ability factor, g, was derived. Prior intelligence was estimated from vocabulary testing, and adjustment for scores on this test was used to estimate lifetime cognitive change. Relationships between fasting morning plasma cortisol levels and cognitive ability and estimated cognitive change were tested. Models were adjusted for potential confounding and/or mediating variables including metabolic and cardiovascular variables.
In age-adjusted analyses, higher fasting cortisol levels were not associated with current g or with performance in individual cognitive domains. However, higher fasting cortisol levels were associated with greater estimated cognitive decline in g and in tests of working memory and processing speed, independent of mood, education, metabolic variables, and cardiovascular disease (P < 0.05).
High morning cortisol levels in elderly people with type 2 diabetes are associated with estimated age-related cognitive change. Strategies targeted at lowering cortisol action may be useful in ameliorating cognitive decline in individuals with type 2 diabetes.
2 型糖尿病患者认知障碍的风险增加，但机制尚不确定。啮齿动物和人类的皮质醇水平升高与认知障碍有关。我们旨在确定空腹皮质醇水平是否与认知能力相关，并在 2 型糖尿病老年人群中评估其一生中的认知变化。
这是一项横断面研究，纳入了居住在苏格兰洛锡安区（爱丁堡 2 型糖尿病研究）的 1066 名年龄在 60-75 岁之间的 2 型糖尿病男性和女性。测试了他们的记忆、非言语推理、信息处理速度、执行功能和心理灵活性等认知能力，并得出了一个一般认知能力因素 g。通过词汇测试估计了之前的智力水平，并对该测试的分数进行了调整，以估计一生中的认知变化。测试了空腹晨血浆皮质醇水平与认知能力和估计认知变化之间的关系。模型调整了代谢和心血管变量等潜在混杂和/或中介变量。
在年龄调整分析中，较高的空腹皮质醇水平与当前 g 或个别认知领域的表现无关。然而，较高的空腹皮质醇水平与 g 以及工作记忆和处理速度测试中的估计认知下降相关，独立于情绪、教育、代谢变量和心血管疾病（P < 0.05）。
2 型糖尿病老年患者清晨皮质醇水平较高与估计的与年龄相关的认知变化有关。针对降低皮质醇作用的策略可能对改善 2 型糖尿病患者的认知下降有用。
