The "Yubi-wakka" or the finger-ring test was developed and validated to predict sarcopenia, disability and even mortality. The present study was conducted to elucidate the prevalence of frailty defined by this test and the relationship between other indexes.

Overall, 5405 subjects aged 65 to 74 years were included in this study. The participants surrounded their calf with their own finger-ring and it was assessed whether the calf was larger, just fit, or smaller than the finger-ring.

Nearly 38.8% of the subjects calves were "larger", 45.6% were "just fit" and 15.6% were "smaller", which was the positive test result. The positive rate was found to be different among different medical facilities. Comparing the "larger" and "smaller" groups, body weight, red blood cell count, serum lipids, uric acid and liver enzymes were found to differ significantly. Metabolic syndrome was more common in the "larger" group. Low body mass index represented an independent risk factor in both males and females. Additionally, the risk factors for positive test results among males included positive urinary glucose, higher aspartate aminotransferase, systolic blood pressure and low alanine transaminase. Smoking, high level of hemoglobin and old age were risk factors for positive test results among females.

This simple and feasible test for the primary care setting does not require the use of any devices. However, the positive rate differed among various clinics. The test could possibly identify subjects without metabolic syndrome and fatty liver.

Source: Fujii H, Kodani E, Kaneko T, et al. "Yubi-wakka" (Finger-Ring) Test: A Tool to Detect Prefrailty in Elderly Populations, a Pilot Study. J Clin Med Res. 2019 Sep;11(9):623-628.