title: Risk factors for predicting progression from mild cognitive impairment to Alzheimer's disease: a systematic review and meta-analysis of cohort studies.
abstract: OBJECTIVE
  We sought to identify the risk factors for predicting the progression from mild cognitive impairment (MCI) to Alzheimer's disease (AD).
  
  
  METHODS
  We searched 6 electronic databases for cohort studies published from January 1966 to March 2015. Eligible studies were required to be relevant to the subject and provide sufficient data for our needs.
  
  
  RESULTS
  60 cohort studies with 14,821 participants from 16 countries were included in the meta-analysis. The strongest positive associations between risk factors and the progression from MCI to AD were found for abnormal cerebrospinal fluid (CSF), phosphorylated τ (p-τ) (relative risk (RR)=2.43, 95% CI=1.70 to 3.48), abnormal CSF τ/Aβ1-42 (RR=3.77, 95% CI=2.34 to 6.09), hippocampal atrophy (RR=2.59, 95% CI=1.95 to 3.44), medial temporal lobe atrophy (RR=2.11, 95% CI=1.70 to 2.63) and entorhinal atrophy (RR=2.03, 95% CI=1.57 to 2.62). Further positive associations were found for the presence of apolipoprotein E (APOE)ε4ε4 and at least 1 APOEε4 allele, CSF total-τ (t-τ), white matter hyperintensity volume, depression, diabetes, hypertension, older age, female gender, lower mini-mental state examination (MMSE) score and higher AD assessment scale cognitive subscale (ADAS-cog) score. Negative associations were found for high body mass index (RR=0.85, 95% CI=0.76 to 0.96) and higher auditory verbal learning test delay score (RR=0.86, 95% CI=0.77 to 0.96).
  
  
  CONCLUSIONS
  Patients with MCI with APOEε4, abnormal CSF τ level, hippocampal and medial temporal lobe atrophy, entorhinal atrophy, depression, diabetes, hypertension, older age, female gender, lower MMSE score and higher ADAS-cog score, had a high risk for the progression to AD.
authors.affiliation: Department of Neurology, Qingdao Municipal Hospital, School of Medicine, Qingdao University, Qingdao, China.
authors.forename: Jie-Qiong
authors.initials: JQ
authors.lastname: Li
authors.affiliation: Department of Neurology, Qingdao Municipal Hospital, School of Medicine, Qingdao University, Qingdao, China Department of Neurology, Qingdao Municipal Hospital, Nanjing Medical University, Qingdao, China College of Medicine and Pharmaceutics, Ocean University of China, Qingdao, China.
authors.forename: Lan
authors.initials: L
authors.lastname: Tan
authors.affiliation: Department of Neurology, Qingdao Municipal Hospital, Nanjing Medical University, Qingdao, China.
authors.forename: Hui-Fu
authors.initials: HF
authors.lastname: Wang
authors.affiliation: College of Medicine and Pharmaceutics, Ocean University of China, Qingdao, China.
authors.forename: Meng-Shan
authors.initials: MS
authors.lastname: Tan
authors.affiliation: College of Medicine and Pharmaceutics, Ocean University of China, Qingdao, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Tan
authors.affiliation: Department of Neurology, Qingdao Municipal Hospital, School of Medicine, Qingdao University, Qingdao, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Xu
authors.affiliation: Department of Neurology, Qingdao Municipal Hospital, School of Medicine, Qingdao University, Qingdao, China.
authors.forename: Qing-Fei
authors.initials: QF
authors.lastname: Zhao
authors.affiliation: Department of Neurology, Qingdao Municipal Hospital, School of Medicine, Qingdao University, Qingdao, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Neurology, Qingdao Municipal Hospital, Nanjing Medical University, Qingdao, China.
authors.forename: Teng
authors.initials: T
authors.lastname: Jiang
authors.affiliation: Department of Neurology, Qingdao Municipal Hospital, School of Medicine, Qingdao University, Qingdao, China Department of Neurology, Qingdao Municipal Hospital, Nanjing Medical University, Qingdao, China College of Medicine and Pharmaceutics, Ocean University of China, Qingdao, China Department of Neurology, Memory and Aging Center, University of California, San Francisco, California, USA.
authors.forename: Jin-Tai
authors.initials: JT
authors.lastname: Yu
mesh_terms: D000544:Alzheimer Disease / Q000134:cerebrospinal fluid / Q000150:complications / Q000209:etiology* / Q000235:genetics / Q000473:pathology / Q000523:psychology; D060825:Cognitive Dysfunction / Q000134:cerebrospinal fluid / Q000150:complications / Q000235:genetics / Q000473:pathology / Q000523:psychology; D015331:Cohort Studies; D018450:Disease Progression; D006801:Humans; D009483:Neuropsychological Tests; D012307:Risk Factors; D012727:Sex Characteristics
keywords: ALZHEIMER'S DISEASE; META-ANALYSIS; SYSTEMATIC REVIEWS