title: An updated meta-analysis of cohort studies: Diabetes and risk of Alzheimer's disease.
abstract: BACKGROUND
  In recently, several large longitudinal population-based studies have shown that the rate of cognitive decline is accelerated in elderly people with diabetes mellitus. But the relation between diabetes and AD is still an area of controversy. The objective of this review was to update the evidence for or against diabetes as a risk factor of AD.
  
  
  METHODS
  We searched the literature from their inception to May 2016 without restriction of language. We included all longitudinal population-based studies examining the association between diabetes and risk of AD. The meta-analysis was conducted using Stata software.
  
  
  RESULTS
  A total of 17 studies involving 1,746,777 individuals were included. After pooling these 17 studies, subjects with diabetes had significant higher incidence of AD than those without diabetes (RR: 1.53, 95% CI: 1.42-1.63). When stratified by ethnicity, five cohorts were identified as Eastern populations, twelve were identified as Western populations. The Relative risk of AD in Western populations and Eastern populations were 1.36(1.18-1.53) and 1.62(1.49-1.75).
  
  
  CONCLUSIONS
  The risk of AD is higher among people with diabetes than in the general population, especially in Eastern populations. So the necessary treatment measures should be taken in order to decrease the risk of AD.
authors.affiliation: Fuzhou Medical College of Nanchang University, Fuzhou 344000, China.
authors.forename: Jieyu
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Fuzhou Medical College of Nanchang University, Fuzhou 344000, China.
authors.forename: Chunxiang
authors.initials: C
authors.lastname: Chen
authors.affiliation: Fuzhou Medical College of Nanchang University, Fuzhou 344000, China.
authors.forename: Shuizhen
authors.initials: S
authors.lastname: Hua
authors.affiliation: Fuzhou Medical College of Nanchang University, Fuzhou 344000, China.
authors.forename: Hairong
authors.initials: H
authors.lastname: Liao
authors.affiliation: Fuzhou Medical College of Nanchang University, Fuzhou 344000, China.
authors.forename: Meixiang
authors.initials: M
authors.lastname: Wang
authors.affiliation: Fuzhou Medical College of Nanchang University, Fuzhou 344000, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Xiong
authors.affiliation: Fuzhou Medical College of Nanchang University, Fuzhou 344000, China. Electronic address: cdfycaofei@outlook.com.
authors.forename: Fei
authors.initials: F
authors.lastname: Cao
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000453:epidemiology* / Q000209:etiology*; D003072:Cognition Disorders / Q000453:epidemiology / Q000209:etiology; D015331:Cohort Studies; D003920:Diabetes Mellitus / Q000453:epidemiology*; D005260:Female; D006801:Humans; D015994:Incidence; D012307:Risk Factors
keywords: Alzheimer's disease; Diabetes; Meta-analysis