title: Modifiable predictors of dementia in mild cognitive impairment: a systematic review and meta-analysis.
abstract: OBJECTIVE
  Public health campaigns encouraging early help seeking have increased rates of mild cognitive impairment (MCI) diagnosis in Western countries, but we know little about how to treat or predict dementia outcomes in persons with the condition.
  
  
  METHODS
  The authors searched electronic databases and references for longitudinal studies reporting potentially modifiable risk factors for incident dementia after MCI. Two authors independently evaluated study quality using a checklist. Meta-analyses were conducted of three or more studies.
  
  
  RESULTS
  There were 76 eligible articles. Diabetes and prediabetes increased risk of conversion from amnestic MCI to Alzheimer's dementia; risk in treated versus untreated diabetes was lower in one study. Diabetes was also associated with increased risk of conversion from any-type or nonamnestic MCI to all-cause dementia. Metabolic syndrome and prediabetes predicted all-cause dementia in people with amnestic and any-type MCI, respectively. Mediterranean diet decreased the risk of conversion to Alzheimer's dementia. The presence of neuropsychiatric symptoms or lower serum folate levels predicted conversion from any-type MCI to all-cause dementia, but less formal education did not. Depressive symptoms predicted conversion from any-type MCI to all-cause dementia in epidemiological but not clinical studies.
  
  
  CONCLUSIONS
  Diabetes increased the risk of conversion to dementia. Other prognostic factors that are potentially manageable are prediabetes and the metabolic syndrome, neuropsychiatric symptoms, and low dietary folate. Dietary interventions and interventions to reduce neuropsychiatric symptoms, including depression, that increase risk of conversion to dementia may decrease new incidence of dementia.
authors.affiliation: From the Division of Psychiatry, University College London; and the Department of Psychiatry and Behavioral Sciences, Johns Hopkins Bayview Medical Center, Baltimore.
authors.forename: Claudia
authors.initials: C
authors.lastname: Cooper
authors.forename: Andrew
authors.initials: A
authors.lastname: Sommerlad
authors.forename: Constantine G
authors.initials: CG
authors.lastname: Lyketsos
authors.forename: Gill
authors.initials: G
authors.lastname: Livingston
mesh_terms: D000544:Alzheimer Disease / Q000453:epidemiology*; D060825:Cognitive Dysfunction / Q000453:epidemiology*; D003704:Dementia / Q000453:epidemiology; D003863:Depression / Q000453:epidemiology; D003920:Diabetes Mellitus / Q000453:epidemiology; D038441:Diet, Mediterranean; D018450:Disease Progression; D004522:Educational Status; D005492:Folic Acid / Q000097:blood; D006801:Humans; D008137:Longitudinal Studies; D024821:Metabolic Syndrome / Q000453:epidemiology; D011236:Prediabetic State / Q000453:epidemiology; D065840:Protective Factors; D012307:Risk Factors
chemical_list: D005492:Folic Acid