Meta-analysis of modifiable risk factors for Alzheimer's disease

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#aged #aged-80-and-over #alzheimer-disease #humans #life-style

Meta-analysis of modifiable risk factors for Alzheimer's disease

Xu et al., 2015 | J Neurol Neurosurg Psychiatry | Meta Analysis

Citation

Xu Wei, Tan Lan, ... Yu Jin-Tai. Meta-analysis of modifiable risk factors for Alzheimer's disease. J Neurol Neurosurg Psychiatry. 2015-Dec;86(12):1299-306. doi:10.1136/jnnp-2015-310548

Abstract

BACKGROUND: The aetiology of Alzheimer's disease (AD) is believed to involve environmental exposure and genetic susceptibility. The aim of our present systematic review and meta-analysis was to roundly evaluate the association between AD and its modifiable risk factors. METHODS: We systematically searched PubMed and the Cochrane Database of Systematic Reviews from inception to July 2014, and the references of retrieved relevant articles. We included prospective cohort studies and retrospective case-control studies. RESULTS: 16,906 articles were identified of which 323 with 93 factors met the inclusion criteria for meta-analysis. Among factors with relatively strong evidence (pooled population >5000) in our meta-analysis, we found grade I evidence for 4 medical exposures (oestrogen, statin, antihypertensive medications and non-steroidal anti-inflammatory drugs therapy) as well as 4 dietary exposures (folate, vitamin E/C and coffee) as protective factors of AD. We found grade I evidence showing that one biochemical exposure (hyperhomocysteine) and one psychological condition (depression) significantly increase risk of developing AD. We also found grade I evidence indicative of complex roles of pre-existing disease (frailty, carotid atherosclerosis, hypertension, low diastolic blood pressure, type 2 diabetes mellitus (Asian population) increasing risk whereas history of arthritis, heart disease, metabolic syndrome and cancer decreasing risk) and lifestyle (low education, high body mass index (BMI) in mid-life and low BMI increasing the risk whereas cognitive activity, current smoking (Western population), light-to-moderate drinking, stress, high BMI in late-life decreasing the risk) in influencing AD risk. We identified no evidence suggestive of significant association with occupational exposures. CONCLUSIONS: Effective interventions in diet, medications, biochemical exposures, psychological condition, pre-existing disease and lifestyle may decrease new incidence of AD.

Key Findings

16,906 articles were identified of which 323 with 93 factors met the inclusion criteria for meta-analysis. Among factors with relatively strong evidence (pooled population >5000) in our meta-analysis, we found grade I evidence for 4 medical exposures (oestrogen, statin, antihypertensive medications and non-steroidal anti-inflammatory drugs therapy) as well as 4 dietary exposures (folate, vitamin E/C and coffee) as protective factors of AD. We found grade I evidence showing that one biochemical e

Outcomes Measured

  • depression
  • blood pressure
  • diastolic blood pressure
  • inflammatory markers

Population

Field Value
Population See abstract
Sample Size See abstract
Age Range See abstract
Condition depression

MeSH Terms

  • Aged
  • Aged, 80 and over
  • Alzheimer Disease
  • Humans
  • Life Style
  • Motor Activity
  • Preexisting Condition Coverage
  • Risk Factors

Evidence Classification

  • Level: Meta Analysis
  • Publication Types: Journal Article, Meta-Analysis, Systematic Review
  • Vertical: vitamin-e

Provenance

Source extracted via PubMed E-utilities API on 2026-04-09