Dataset Information

Vitamin D status, cognitive decline and incident dementia: the Canadian Study of Health and Aging.

ABSTRACT:

Objective

Vitamin D could prevent cognitive decline because of its neuroprotective, anti-inflammatory and antioxidant properties. This study aimed to evaluate the associations of plasma 25-hydroxyvitamin D (25(OH)D) concentrations with global cognitive function and incident dementia, including Alzheimer's disease (AD).

Methods

The Canadian Study of Health and Aging is a 10-year cohort study of a representative sample of individuals aged 65 years or older. A total of 661 subjects initially without dementia with frozen blood samples and follow-up data were included. Global cognitive function was measured using the validated Modified Mini-Mental State (3MS) examination. A consensus diagnosis of all-cause dementia and AD was made between the physician and the neuropsychologist according to published criteria. Cognitive decline for a 5-year increase in age at specific 25(OH)D concentrations was obtained using linear mixed models with repeated measures. Hazard ratios of incident dementia and AD were obtained using semi-parametric proportional hazards models with age as time scale.

Results

Over a mean follow-up of 5.4 years, 141 subjects developed dementia of which 100 were AD. Overall, no significant association was found between 25(OH)D and cognitive decline, dementia or AD. Higher 25(OH)D concentrations were associated with an increased risk of dementia and AD in women, but not in men.

Conclusion

This study does not support a protective effect of vitamin D status on cognitive function. Further research is needed to clarify the relation by sex.

SUBMITTER: Duchaine CS

PROVIDER: S-EPMC7351937 | biostudies-literature | 2020 Jun

REPOSITORIES: biostudies-literature

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Publications

Vitamin D status, cognitive decline and incident dementia: the Canadian Study of Health and Aging.

Duchaine Caroline S CS Talbot Denis D Nafti Mohamed M Giguère Yves Y Dodin Sylvie S Tourigny André A Carmichael Pierre-Hugues PH Laurin Danielle D

Canadian journal of public health = Revue canadienne de sante publique 20200203 3

<h4>Objective</h4>Vitamin D could prevent cognitive decline because of its neuroprotective, anti-inflammatory and antioxidant properties. This study aimed to evaluate the associations of plasma 25-hydroxyvitamin D (25(OH)D) concentrations with global cognitive function and incident dementia, including Alzheimer's disease (AD).<h4>Methods</h4>The Canadian Study of Health and Aging is a 10-year cohort study of a representative sample of individuals aged 65 years or older. A total of 661 subjects i ...[more]

PMID: 32016921

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Project description:INTRODUCTION:The global burden of dementia is rising, emphasising the urgent need to develop effective approaches to risk reduction. Recent evidence suggests that common bacterial infections may increase the risk of dementia, however the magnitude and timing of the association as well as the patient groups affected remains unclear. We will review existing evidence of the association between common bacterial infections and incident cognitive decline or dementia. METHODS AND ANALYSIS:We will conduct a comprehensive search of published and grey literature from inception to 18 March 2019. The following electronic databases will be searched; MEDLINE, EMBASE, Global health, PsycINFO, Web of Science, Scopus, Cochrane Library, the Cumulative Index to Nursing and Allied Health Literature, Open Grey and the British Library of Electronic Theses databases. There will be no restrictions on the date, language or geographical location of the studies. We will include longitudinal studies with a common clinically symptomatic bacterial infection as an exposure and incident cognitive decline or dementia as an outcome. Study selection, data extraction and risk of bias will be performed independently by two researchers. We will assess the risk of bias using the Cochrane collaboration approach. The overall quality of the studies will be assessed using the Grading of Recommendations, Assessment, Development and Evaluations criteria. We will explore the heterogeneity of relevant studies and, if feasible, a meta-analysis will be performed, otherwise we will present a narrative synthesis. We will group the results by exposure and outcome definitions and differences will be described by subgroups and outcomes. ETHICS AND DISSEMINATION:Ethical approval will not be required as this is a systematic review of existing research in the public domain. Results will be disseminated in a peer-reviewed journal and presented at national and international meetings and conferences. PROSPERO REGISTRATION NUMBER:CRD42018119294.

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Dataset Information

Vitamin D status, cognitive decline and incident dementia: the Canadian Study of Health and Aging.

Objective

Methods

Results

Conclusion

Publications

Vitamin D status, cognitive decline and incident dementia: the Canadian Study of Health and Aging.

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