Prediction of probable sarcopenia with an alternative method: plantar flexion strength

Sarcopenia is a geriatric syndrome characterized by age-related reduction in muscle mass and strength. Assessment of handgrip strength (HGS) is an essential measurement for the diagnosis of sarcopenia; however, disorders affecting upper limb muscles and joints may pose challenges in assessing handgrip strength. Therefore, the present study aimed to show the validity of plantar flexion strength (PFS) in diagnosing probable sarcopenia and investigating the relations between comprehensive geriatric assessment (CGA) and PFS while determining appropriate cutoff values for PFS.

A total of 304 older participans who underwent CGA were included. The revised criteria of the European Working Group on Sarcopenia in Older People (EWGSOP) were used to determine PFS cutoff values for gender groups. Associations between probable sarcopenia and CGA parameters were investigated using PFS cutoffs.

The mean age was 74.50 ± 7.10, and 170 of the participants (55.9%) were women. The mean HGS was 14.40 ± 5.63 kg in women and 25.08 ± 8.07 kg in men. The mean PFS were 13.17 ± 3.62 and 14.92 ± 3.86 kg respectively. In females, PFS cutoff with sensitivity/specificity; 0.81/0.60 was set at 14.95 kg (AUC 0.69, 95%CI: 0.611-0.772, p < 0.001). In males, PFS cutoff with sensitivity/specificity; 0.80/0.55 was set at 16.80 kg (AUC 0.68, 95%CI: 0.593-0.772, p < 0.001). Probable sarcopenia identified by GMS was associated with basic living activities, mobility, and frailty after adjusting for age and sex (p < 0.001, p = 0.021, and p = 0.011 respectively).

Probable sarcopenia identified by PFS could be associated with CGA. PFS may be useful for evaluating probable sarcopenia in older adults whose HGS cannot be estimated accurately.