Meta-analysis on the interrelationship between sarcopenia and mild cognitive impairment, Alzheimer's disease and other forms of dementia.
Level 3 - non-randomized controlled study
Systematic review and meta-analysis of predominantly observational (cross-sectional and cohort) studies.
PubMed 38715252 · doi:10.1002/jcsm.13485
What was done
A systematic review and meta-analysis (PROSPERO CRD42022366309) searched eight databases and ClinicalTrials.gov up to June 8, 2023, following PRISMA 2020 guidelines. Eligible studies included observational (cross-sectional, cohort) and interventional designs evaluating the association or prevalence of sarcopenia in adults aged ≥50 years with mild cognitive impairment (MCI), Alzheimer's disease (AD), or other dementias. A total of 77 studies (92,058 participants: 71 cross-sectional, 4 cohort, 2 interventional) were qualitatively synthesized, and 26 studies were meta-analyzed using fixed- or random-effects models to calculate pooled odds ratios (OR) with 95% confidence intervals (CI).
What was found
Sarcopenia was significantly associated with each neurocognitive condition evaluated: - Mild cognitive impairment (MCI): pooled OR = 1.58 (95% CI 1.42–1.76; 14 studies). - Alzheimer's disease (AD): pooled OR = 2.97 (95% CI 2.15–4.08; 3 studies). - Non-AD dementia: pooled OR = 1.68 (95% CI 1.09–2.58; 9 studies). Subgroup analyses demonstrated that the magnitude and statistical significance of associations varied according to study design, study population, sarcopenia criteria, and cognitive assessment instruments.
Why it matters
This review demonstrates a consistent statistical association between sarcopenia and several stages of neurocognitive impairment in older adults. The findings highlight the potential value of screening for and managing sarcopenia in geriatric populations experiencing cognitive dysfunction.
Limits
The evidence base is dominated by cross-sectional designs (71 of 77 studies), precluding conclusions regarding causality or temporal directionality (only three cohorts examined incident MCI and one examined incident sarcopenia). Included studies had substantial heterogeneity in the diagnostic criteria for both sarcopenia and cognitive disorders. Geographic representation was skewed toward Asian community-dwelling older adults (n = 38), and 21 studies did not specify the etiology of dementia.
Cited by
- supports A 2024 meta-analysis found a 56% increased risk of mild cognitive decline and an almost 300% increased risk for Alzheimer's dementia in people with the highest levels of sarcopenia.