Physical activity and cohabitation status moderate the link between diabetes mellitus and cognitive performance in a community-dwelling elderly population in Germany

Aims/Hypothesis
The increasing number of people with dementia and cognitive impairments makes it essential to detect and prevent modifiable risk factors of dementia. This study focuses on type 2 diabetes mellitus, especially on undiagnosed cases and their increased risk of cognitive impairment. Furthermore, the potential of physical activity and social integration to moderate the relation between diabetes and cognitive impairment is assessed.
Methods
We used cross-sectional data from 1299 participants of the Berlin Aging Study II (BASE-II) aged between 60 to 84 years and performed logistic regression models to analyze the association of diabetes status, physical activity, and cohabitation status with poor cognitive performance. Cognitive performance was measured with the Consortium to Establish a Registry for Alzheimer's Disease (CERAD)-Plus test battery.
Results
Undiagnosed diabetes (odds ratio (OR) = 2.12, p = 0.031), physical inactivity (OR = 1.43, p = 0.008) and non-cohabiting (OR = 1.58, p = 0.002) were associated with an increased likelihood of poor cognitive performance. The highest odds were observed in participants who suffered from undiagnosed or insulin-dependent diabetes and, in addition, were inactive (undiagnosed diabetes: OR = 3.44, p = 0.003; insulin-dependent diabetes: OR = 6.19, p = 0.019) or lived alone (undiagnosed diabetes: OR = 4.46, p = 0.006; insulin-dependent diabetes: OR = 6.46 p = 0.052). Physical activity and cohabiting appeared to be beneficial.
Conclusions/Interpretation
Physical activity and cohabitation status moderate the link between diabetes mellitus and cognitive performance. Special attention should be paid to undiagnosed and insulin-dependent diabetes cases, which have a particularly high risk of poor cognitive performance.

研究目的与假设
随着痴呆症与认知障碍患者群体规模持续扩大，识别并干预痴呆可改变危险因素已成为亟需解决的公共卫生议题。本研究聚焦2型糖尿病（type 2 diabetes mellitus），尤其关注未确诊病例及其认知障碍风险升高的关联；同时评估体力活动与社会融合在调节糖尿病与认知障碍间关系中的潜在作用。

研究方法
本研究采用柏林衰老研究二期（Berlin Aging Study II, BASE-II）中1299名年龄介于60至84岁参与者的横断面数据，通过逻辑回归模型分析糖尿病状态、体力活动与同居状态与认知功能不良的关联。认知功能采用阿尔茨海默病登记建立联盟-附加测试组合（Consortium to Establish a Registry for Alzheimer's Disease (CERAD)-Plus test battery）进行评估。

研究结果
未确诊糖尿病（比值比（odds ratio, OR）=2.12，p=0.031）、体力活动不足（OR=1.43，p=0.008）以及独居状态（OR=1.58，p=0.002）均与认知功能不良风险升高显著相关。其中，同时罹患未确诊或胰岛素依赖型糖尿病且缺乏体力活动的参与者，认知功能不良风险最高：未确诊糖尿病组OR=3.44，p=0.003；胰岛素依赖型糖尿病组OR=6.19，p=0.019。而同时患有上述两类糖尿病且独居的参与者，风险同样显著升高：未确诊糖尿病组OR=4.46，p=0.006；胰岛素依赖型糖尿病组OR=6.46，p=0.052。研究显示，体力活动与同居状态具有保护作用。

结论与阐释
体力活动与同居状态可调节糖尿病与认知功能间的关联。临床与研究工作应重点关注未确诊及胰岛素依赖型糖尿病患者，该群体认知功能不良风险显著升高。