Sarcopenia in Informal Caregivers of Persons Living with Dementia: A Scoping Review

Background/Objectives: Dementia caregiving is associated with psychological stress, but the impact on caregivers’ physical health, particularly sarcopenia—the progressive loss of muscle mass, strength, and function—remains under-explored. Sarcopenia is clinically significant as a predictor of falls and disability and is potentially modifiable through exercise and nutrition. This scoping review aimed to map existing evidence on sarcopenia and its components in informal dementia caregivers. Methods: This review followed Joanna Briggs Institute methodology and the PRISMA-ScR checklist. Five databases (PubMed/MEDLINE, Scopus, PsycINFO, ProQuest Dissertations & Theses, medRxiv) were searched from 2000 to July 2025 for studies of adult informal caregivers of persons with dementia reporting at least one sarcopenia domain (muscle mass, muscle strength, or physical performance). Screening and data charting were performed independently by two reviewers. No formal critical appraisal or meta-analysis was undertaken because the review aimed to map the extent, characteristics and methodological gaps of the available evidence. Results: Six sources were included: four cross-sectional studies, one retrospective cohort and one prospective cohort. No study used consensus definitions (EWGSOP2/AWGS); most examined surrogate markers such as handgrip strength or gait speed. Findings were heterogeneous: some studies suggested impaired physical function, frailty, and endurance deficits among caregivers, while others reported mixed results. Nutritional risk was evident in one study, with 23% malnourished and 41% at risk. No interventional studies were identified. Conclusions: The evidence base on sarcopenia in dementia caregivers is sparse and inconsistent, relying largely on proxy measures and cross-sectional data. Preliminary findings suggest that informal caregivers, especially older spousal caregivers, may be vulnerable to declines in muscle health and function. Future research should adopt standardised sarcopenia criteria, employ longitudinal designs, and test interventions such as resistance exercise and nutritional supplementation to mitigate risk.