Centre for Life Course Health Research, Faculty of Medicine, University of Oulu, Oulu, Finland.
Biocenter Oulu, University of Oulu, Oulu, Finland.
Scand J Prim Health Care. 2020 Sep;38(3):281-290. doi: 10.1080/02813432.2020.1802140. Epub 2020 Aug 10.
Worldwide, we are observing a rising prevalence of dementia and mild cognitive impairments that often co-occur with the heightened incidence of non-communicable diseases in the elderly. It is suggested that type 2 diabetes and defects in glucose metabolism might predispose to poorer cognitive performances and more rapid decline in old age.
to address existing knowledge gaps in this area, we systematically reviewed the literature to identify whether patients with type 2 diabetes (T2DM) and pre-diabetes are at a higher risk of poorer cognitive performance, and whether the risk (if any) might affect specific cognitive abilities. We concentrated the review on elderly individuals (65 years or older) at intake. In total, 3251 original articles were retrieved, of which 17 met our inclusion and quality control criteria, which comprised 12 structured questions used to define the articles.
11 of 17 studies found a statistically significant decline in cognition among individuals who had T2DM or pre-diabetes compared to their non-diabetic counterparts. The association between diabetes and cognitive decline was not always clear, and the extent of the cognitive tests used seemed to have the greatest effect on the results.
Focusing on a population age 65 years and over, we found insufficient evidence to support an association between pre-diabetes stages and mild cognitive impairment. However, there is consistent evidence to support diabetes as an independent risk factor for low cognitive ability in the elderly. Finally, we found insufficient evidence to support effect of T2DM on distinct cognitive ability due to the scarcity of comparable findings.
在全球范围内，我们观察到痴呆症和轻度认知障碍的患病率不断上升，而这些疾病往往与老年人中非传染性疾病发病率的升高同时发生。有研究表明，2 型糖尿病和葡萄糖代谢缺陷可能使老年人的认知表现更差，认知能力下降更快。
为了解决该领域现有知识空白，我们系统地回顾了文献，以确定 2 型糖尿病（T2DM）和糖尿病前期患者的认知表现是否更差，以及这种风险（如果存在）是否会影响特定的认知能力。我们将综述重点放在入组时年龄在 65 岁或以上的老年人身上。总共检索到 3251 篇原始文章，其中 17 篇符合我们的纳入和质量控制标准，这些标准包括用于定义文章的 12 个结构化问题。
17 项研究中有 11 项发现，与非糖尿病患者相比，患有 T2DM 或糖尿病前期的个体认知能力下降具有统计学意义。糖尿病与认知能力下降之间的关联并不总是明确的，并且所使用的认知测试的程度似乎对结果的影响最大。
我们专注于年龄在 65 岁及以上的人群，发现没有足够的证据支持糖尿病前期阶段与轻度认知障碍之间存在关联。然而，有一致的证据支持糖尿病是老年人认知能力低下的独立危险因素。最后，由于缺乏可比的发现，我们发现没有足够的证据支持 T2DM 对特定认知能力的影响。
