Inflammatory markers associated with dementia: a systematic review and meta-analysis

Area of Science:

• Neuroscience
• Immunology
• Gerontology

Background:

• Dementia is linked to modifiable risk factors, including mental illness.
• The inflammatory-mediated neurodegeneration hypothesis suggests mental illness triggers inflammation, leading to dementia.
• Previous meta-analyses have not examined inflammatory markers across major dementia subtypes.

Purpose of the Study:

• To investigate if Alzheimer's disease (AD), vascular dementia (VaD), dementia with Lewy bodies (DLB), and fronto-temporal dementia (FTD) show increased inflammation compared to controls.
• To determine if these associations persist independently of other inflammatory conditions.
• To explore similarities in inflammatory profiles across dementia subtypes.

Main Methods:

• A systematic meta-analysis was conducted.
• Searches were performed across PubMed, EMBASE, PsycINFO, and CINAHL databases.
• 41 eligible studies were included in the analysis.

Main Results:

• Alzheimer's disease (AD) is clearly associated with an inflammatory response.
• Tentative evidence suggests vascular dementia (VaD), dementia with Lewy bodies (DLB), and fronto-temporal dementia (FTD) are also linked to inflammation.
• The inflammatory response patterns appear distinct among these dementia conditions.

Conclusions:

• Data for VaD, DLB, FTD, and specific inflammatory markers were limited.
• AD, VaD, DLB, and FTD may involve distinct inflammatory processes not explained by common comorbidities.
• The causal role of inflammation in dementia development and its link to prior mental illness require further investigation.