Sarcopenia and coexistent risk factors detected using the ‘Yubi-wakka’ (finger-ring) test in adults aged over 65 years in the public annual health check-up in Tama City, Tokyo: a cross-sectional study

OBJECTIVES: To examine the positive rate of sarcopenia using the ‘Yubi-wakka’ (finger-ring) test and associated risk factors among adults aged 65 years and older. DESIGN: Cross-sectional study. SETTING: We used the Yubi-wakka test, which has been developed and validated as a predictor of sarcopenia, frailty, disability and mortality. A positive test result is indicated by a smaller calf circumference than the finger-ring. The test was administered during annual health check-ups among residents of Tama City, Japan. PARTICIPANTS: During the 2019 fiscal year, 12 894 individuals aged 65 years and older underwent the Yubi-wakka test at primary care clinics. INTERVENTIONS: Examinees conducted the test themselves in a seated position. They formed a ring around their calf using both thumbs and index fingers and judged whether their calf was larger, the same or smaller than their finger-ring. PRIMARY AND SECONDARY OUTCOME MEASURES: We compared anthropometric and serological data between the positive (smaller calf) and negative (larger calf) test result groups. RESULTS: The positive rate was 15.4% among men and 18.5% among women. The prevalence of a positive result was higher in those aged ≥80 years than in younger age groups in both sexes (men: 22.8%; women: 28.8%). Multivariate logistic regression analysis showed that a diagnosis of metabolic syndrome was a risk factor for detecting a positive test result in women aged 65–74 years (OR 3.445; 95% CI 1.44 to 8.29) and ≥75 years (OR 3.37; 95% CI 1.97 to 5.78). CONCLUSIONS: Because the Japanese population is healthy and lives long, interventions against sarcopenia are important, especially for older adults aged >75 years. The presence of metabolic syndrome may be a risk factor for sarcopenia (as detected by the Yubi-wakka test) and future frailty, and requires closer attention, especially among women.