Abstract
AIM: This study aimed to develop an easy-to-use assessment that can be carried out anywhere by investigating the association between the ability to open a polyethylene terephthalate (PET) bottle cap and locomotive syndrome (LS), frailty and sarcopenia, and the screening ability of this method. METHODS: This cross-sectional study was carried out between July 2022 and February 2024, analyzing 341 community-dwelling Japanese older adults (mean age 80.0 ± 6.9 years). We used odds ratios (OR) and their 95% confidence intervals (CI) to assess the association between the ability to open a PET bottle cap and LS, frailty and sarcopenia, as well as the screening ability of this method. LS was evaluated using the stand-up and two-step tests and Geriatric Locomotive Function Scale-5; frailty was evaluated using the Japanese version of the Cardiovascular Health Study criteria; and sarcopenia was evaluated using grip strength, walking speed and skeletal muscle mass index. RESULTS: After adjusting for age, sex and body mass index, the binary logistic regression analysis showed that the inability to open a PET bottle cap was associated with LS stages 2 and 3 (OR 2.72, 95% CI 1.46-5.07), frailty according to the Japanese version of the Cardiovascular Health Study criteria (OR 3.38, 95% CI 1.23-9.24) and sarcopenia (OR 3.61, 95% CI 1.67-7.79). The receiver operating characteristic curve analysis showed moderate screening ability for LS, frailty and sarcopenia, with a positive predictive value of 97.4% for LS, and 93.9% for pre-frailty and frailty. CONCLUSIONS: Notably, the positive predictive value was high for LS, and pre-frailty/frailty using the PET bottle method. The PET bottle method is "simple" and requires just "one action," and it holds promise for practical social implementation as a comprehensive assessment of LS (stages 2 and 3), frailty and sarcopenia. Geriatr Gerontol Int 2025; 25: 905-910.