Association between diabetes and causes of dementia: Evidence from a clinicopathological study

ABSTRACT. Background: Diabetes mellitus is a risk factor for dementia, especially for vascular dementia (VaD), but there is no consensus on diabetes as a risk factor for Alzheimer's disease (AD) and other causes of dementia. Objective: To explore the association between diabetes and the neuropathological etiology of dementia in a large autopsy study. Methods: Data were collected from the participants of the Brain Bank of the Brazilian Aging Brain Study Group between 2004 and 2015. Diagnosis of diabetes was reported by the deceased's next-of-kin. Clinical dementia was established when CDR ≥ 1 and IQCODE > 3.41. Dementia etiology was determined by neuropathological examination using immunohistochemistry. The association of diabetes with odds of dementia was investigated using multivariate logistic regression. Results: We included 1,037 subjects and diabetes was present in 279 participants (27%). The prevalence of dementia diagnosis was similar in diabetics (29%) and non-diabetics (27%). We found no association between diabetes and dementia (OR = 1.22; 95%CI = 0.81-1.82; p = 0.34) on the multivariate analysis. AD was the main cause of dementia in both groups, while VaD was the second-most-frequent cause in diabetics. Other mixed dementia was the second-most-common cause of dementia and more frequent among non-diabetics (p = 0.03). Conclusion: Diabetes was not associated with dementia in this large clinicopathological study.

摘要

背景：糖尿病（Diabetes mellitus）是痴呆的危险因素，尤其与血管性痴呆（vascular dementia, VaD）相关，但目前对于糖尿病是否为阿尔茨海默病（Alzheimer's disease, AD）及其他类型痴呆的危险因素尚无共识。

目的：在一项大型尸检研究中探讨糖尿病与痴呆神经病理病因学之间的关联。

方法：研究数据采集自2004年至2015年巴西老化脑研究组脑库（Brain Bank）的受试者。糖尿病诊断由死者近亲属提供。当临床痴呆评定量表（Clinical Dementia Rating, CDR）评分≥1且老年认知下降知情者问卷（Informant Questionnaire on Cognitive Decline in the Elderly, IQCODE）得分＞3.41时，确诊临床痴呆。通过免疫组织化学（immunohistochemistry）进行神经病理检查以明确痴呆病因。采用多因素logistic回归（multivariate logistic regression）分析探讨糖尿病与痴呆发生风险的关联。

结果：本研究共纳入1037名受试者，其中279名（27%）患有糖尿病。糖尿病组与非糖尿病组的痴呆诊断患病率相近，分别为29%和27%。多因素分析显示，糖尿病与痴呆无显著关联（比值比（odds ratio, OR）=1.22；95%置信区间（95% confidence interval, 95%CI）=0.81-1.82；p=0.34）。两组痴呆的主要病因均为阿尔茨海默病；在糖尿病组中，血管性痴呆为第二常见病因，而非糖尿病组中混合型痴呆为第二常见病因，且其患病率显著更高（p=0.03）。

结论：在这项大型临床病理研究中，糖尿病与痴呆无显著关联。