Utility of handgrip strength cut-offs for identification of weakness and disability in community-dwelling older people with mild cognitive impairment and Alzheimer’s disease

Objectives To evaluate the utility of handgrip strength cut-offs for the identification of weakness and Instrumental Activities of Daily Living (IADL) disability in elderly people with neurocognitive disorders. Methods Cross-sectional study of community-dwelling elderly individuals with Alzheimer’s disease (AD, n = 40) and mild cognitive impairment (MCI, n = 22); healthy individuals (n = 36) were recruited as controls. Handgrip cut-offs included European Working Group for Sarcopenic Older People (EWGSOP2), Cardiovascular Healthy Study (CHS) and the Frailty in Brazilian Older People Study from Rio de Janeiro (FIBRA RJ) cut-offs. Handgrip strength indexes were calculated by dividing handgrip strength values by cut-off values and the weakness prevalence for each cut-off value was compared among groups. Correlation analyses were employed to evaluate the relationship between Lawton Scale and handgrip strength (crude value and indexes). Results All handgrip strength indexes were lower in the AD group (p < 0.05), whereas the prevalence of weakness was significantly higher in the AD group only when the CHS cut-off was applied (AD = 47.5%, MCI and control = 18.2%, p < 0.01). Significantly positive correlations were identified between the Lawton ADL scale and handgrip indexes for all cut-offs (p < 0.05), but not between Lawton scale and crude handgrip (p = 0.75). Conclusions Only the CHS cut-off allowed proper differentiation of the weakness prevalence between groups. In addition, adjusting handgrip strength values according to cut-offs was necessary to determine the correlation between strength and disability in cognitively impaired elderly individuals.