Decrease in the usual walking speed and body fat percentage associated with a deterioration in long-term care insurance certification levels.

Abstract

In Japan, the number of older adults requiring long-term care insurance (LTCI) is increasing and the cost is becoming a social problem. In these fields, the role of geriatric rehabilitation includes maintaining the physical function and LTCI certification levels. The prevalence of sarcopenia is high among older adults requiring LTCI certification, and there are many opportunities to assess the handgrip strength, walking speed, and muscle mass. This study aimed to identify sarcopenia-related assessments sensitive to transitions in LTCI certification levels and determine cut-off values to predict them. This prospective cohort study analyzed 98 daycare users (mean age±standard error: 78.5±0.8 years) between March 2019 and 2023. The participants received LTCI certification before the study, and their levels were renewed between baseline and follow-up (six months later). The measurements included handgrip strength, usual walking speed, body composition, and SARC-F score. Participants were classified into maintenance, deterioration, and improvement groups according to the changes in their LTCI certification levels. We identified factors contributing to the deterioration of LTCI certification levels using baseline and before and after comparisons, multivariate analyses, and receiver operating characteristic analyses. No significant differences were observed in the baseline data among the groups. Only the deterioration group showed significant changes in the usual walking speed (baseline: 0.64±0.25 m/s, follow-up: 0.53±0.21 m/s, P = 0.008) and body fat percentage (baseline: 29.2±9.9%, follow-up: 27.7±10.3%, P = 0.047). Binomial logistic regression showed that changes in usual walking speed (P = 0.042) and body fat percentage (P = 0.011) were significantly associated with the deterioration of LTCI certification levels, even after adjustment. The cutoff values of change to discriminate the deterioration of LTCI certification levels were -0.14 m/s at the usual walking speed (P = 0.047) and -1.0% for body fat percentage (P = 0.029). Decreases in usual walking speed and body fat percentage may predict worse certification levels in older adults requiring LTCI.