Dataset Information

Combining modifiable risk factors and risk of dementia: a systematic review and meta-analysis.

ABSTRACT:

Objective

To systematically review the literature relating to the impact of multiple co-occurring modifiable risk factors for cognitive decline and dementia.

Design

A systematic review and meta-analysis of the literature relating to the impact of co-occurring key risk factors for incident cognitive decline and dementia. All abstracts and full text were screened independently by two reviewers and each article assessed for bias using a standard checklist. A fixed effects meta-analysis was undertaken.

Data sources

Databases Medline, Embase and PsycINFO were searched from 1999 to 2017.

Eligibility criteria

For inclusion articles were required to report longitudinal data from participants free of cognitive decline at baseline, with formal assessment of cognitive function or dementia during follow-up, and an aim to examine the impact of additive or clustered comorbid risk factor burden in with two or more core modifiable risk factors.

Results

Seventy-nine full-text articles were examined. Twenty-two articles (18 studies) were included reporting data on >40?000 participants. Included studies consistently reported an increased risk associated with greater numbers of intraindividual risk factors or unhealthy behaviours and the opposite for healthy or protective behaviours. A meta-analysis of studies with dementia outcomes resulted in a pooled relative risk for dementia of 1.20 (95% CI 1.04 to 1.39) for one risk factor, 1.65 (95% CI 1.40 to 1.94) for two and 2.21 (95% CI 1.78 to 2.73) for three or more, relative to no risk factors. Limitations include dependence on published results and variations in study outcome, cognitive assessment, length of follow-up and definition of risk factor exposure.

Conclusions

The strength of the reported associations, the consistency across studies and the suggestion of a dose response supports a need to keep modifiable risk factor exposure to a minimum and to avoid exposure to additional modifiable risks. Further research is needed to establish whether particular combinations of risk factors confer greater risk than others.

Prospero registration number

42016052914.

SUBMITTER: Peters R

PROVIDER: S-EPMC6352772 | biostudies-literature | 2019 Jan

REPOSITORIES: biostudies-literature

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Publications

Combining modifiable risk factors and risk of dementia: a systematic review and meta-analysis.

Peters Ruth R Booth Andrew A Rockwood Kenneth K Peters Jean J D'Este Catherine C Anstey Kaarin J KJ

BMJ open 20190125 1

<h4>Objective</h4>To systematically review the literature relating to the impact of multiple co-occurring modifiable risk factors for cognitive decline and dementia.<h4>Design</h4>A systematic review and meta-analysis of the literature relating to the impact of co-occurring key risk factors for incident cognitive decline and dementia. All abstracts and full text were screened independently by two reviewers and each article assessed for bias using a standard checklist. A fixed effects meta-analys ...[more]

PMID: 30782689

Similar Datasets

Project description:BackgroundCognitive impairment, including dementia, is a major health concern with the increasing aging population. Preventive measures to delay cognitive decline are of utmost importance. Alzheimer's disease (AD) is the most frequent cause of dementia, increasing in prevalence from <1% below the age of 60 years to >40% above 85 years of age.MethodsWe systematically reviewed selected modifiable factors such as education, smoking, alcohol, physical activity, caffeine, antioxidants, homocysteine (Hcy), n-3 fatty acids that were studied in relation to various cognitive health outcomes, including incident AD. We searched MEDLINE for published literature (January 1990 through October 2012), including cross-sectional and cohort studies (sample sizes > 300). Analyses compared study finding consistency across factors, study designs and study-level characteristics. Selecting studies of incident AD, our meta-analysis estimated pooled risk ratios (RR), population attributable risk percent (PAR%) and assessed publication bias.ResultsIn total, 247 studies were retrieved for systematic review. Consistency analysis for each risk factor suggested positive findings ranging from ~38.9% for caffeine to ~89% for physical activity. Education also had a significantly higher propensity for "a positive finding" compared to caffeine, smoking and antioxidant-related studies. Meta-analysis of 31 studies with incident AD yielded pooled RR for low education (RR = 1.99; 95% CI: 1.30-3.04), high Hcy (RR = 1.93; 95% CI: 1.50-2.49), and current/ever smoking status (RR = 1.37; 95% CI: 1.23-1.52) while indicating protective effects of higher physical activity and n-3 fatty acids. Estimated PAR% were particularly high for physical activity (PAR% = 31.9; 95% CI: 22.7-41.2) and smoking (PAR% = 31.09%; 95% CI: 17.9-44.3). Overall, no significant publication bias was found.ConclusionsHigher Hcy levels, lower educational attainment, and decreased physical activity were particularly strong predictors of incident AD. Further studies are needed to support other potential modifiable protective factors, such as caffeine.

Dataset Information

Combining modifiable risk factors and risk of dementia: a systematic review and meta-analysis.

Objective

Design

Data sources

Eligibility criteria

Results

Conclusions

Prospero registration number

Publications

Combining modifiable risk factors and risk of dementia: a systematic review and meta-analysis.

Similar Datasets

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