Sarcopenia and dynapenia as risk factors for mobility decline in the elderly: an analysis with different cutoff points

Abstract

Mobility, measured by walking speed, is considered the sixth vital sign in the assessment of the elderly. Limiting mobility compromises independence and increases the risk of falls, functional loss, hospitalization and death.The decline in walking speed is a complex process associated with increasing age, low education and income, physical inactivity, smoking, joint disease, diabetes, hypertension, heart disease, lung disease, stroke,depression, cognitive decline as well as the decline in muscle strength (dynapenia) and the reduction in mass, strength and functionality (sarcopenia) as one ages. Although sarcopenia and dynapenia are two important risk factors for mobility decline, the different handgrip strength cutoff points used to define these two conditions may imply distinct effects on this decline over time. For example, in the consensus of the European Working Group on Sarcopenia in Older People published in 2010, the handgrip strength cutoff score to define weakness was < 30 kg for men and < 20 kg for women. However, the consensus reviewin 2019 recommended the cutoff score of handgrip strength < 27 kg for men and < 16 kg for women.Although there are other proposals in the literature for these cutoff points, a recent work by our research group, supported by FAPESP, analyzed 5,783 participants from the Health, Well-Being and Aging Studies (SABE Study) and from EnglishLongitudinal Study of Ageing (ELSA Study) and identified that higher values of handgrip strength such as < 32 kg for men and < 21 kg for women had better accuracy to identify mobility decline than the aforementioned scores.Thus, the opportunity arose to analyze, within this Young Researcher Project, sarcopenia and dynapenia, defined with different cutoff scores for strength, as risk factors for the trajectory of mobility decline in people aged 60 years or more in a follow-up of eight years. This is important, as walking speed is the indicator of severity in the current sarcopenia consensus and early identification of which cutoff points best identify the risk of slowness allow for better chances of successful diagnosis and early interventions. Therefore, the aim of the present study is to analyze sarcopenia and dynapenia, defined with different cutoff points for handgrip strength, as risk factors for mobility decline in the elderly during an eight-year follow-up period.