The Need for a New Cut-off Value to Increase Diagnostic Performance of Bioelectrical Impedance Analysis Compared with Dual-Energy X-ray Absorptiometry to Measure Muscle Mass in Indonesian Elderly.

BACKGROUND: the use of bioelectrical impedance analysis (BIA) is affected by the population setting, the type of BIA, and the cut-off point being used. The aim of this study was to determine the diagnostic performance of BIA to measure muscle mass in Indonesian elderly outpatients aged 60 years or more. METHODS: a cross-sectional study was conducted at the Geriatric Clinic of Cipto Mangunkusumo Hospital from April to June 2018. The muscle mass was measured using BIA Tanita MC-780MA (Tokyo, Japan) with dual-energy x-ray absorptiometry (DXA) as the reference test. Analysis on the cut-off point was performed based on the Asian Working Group of Sarcopenia (AWGS) criteria and the new cut-off point. RESULTS: from 120 subjects, 74 were female (61.7%). The diagnostic performance of BIA based on AWGS criteria only showed sensitivity and specificity of 79.2% and 66.7%. The diagnostic performance of BIA based on the new cut-off point showed sensitivity and specificity of 75% and 92.7%. The new cut-off point using BIA was found to be <6.9 kg/m2 in males (sensitivity 70.6%; specificity 82.8%) and <5 kg/m2 in females (sensitivity 85.7%; specificity 97%). CONCLUSION: the diagnostic performance of BIA Tanita MC-780MA (Tokyo, Japan) was good to measure muscle mass in Indonesian elderly outpatients using a new cut-off point of <6.9 kg/m2 for males and <5 kg/m2 for females.

Diagnostic Performance of Calf Circumference, Thigh Circumference, and SARC-F Questionnaire to Identify Sarcopenia in Elderly Compared to Asian Working Group for Sarcopenia's Diagnostic Standard.

BACKGROUND: sarcopenia is one of many geriatric problems that may lead to major clinical outcomes. Calf and thigh circumference have good correlation with muscle mass, whereas SARC-F questionnaire is very predictive of muscle function. There has not been a study that evaluates the diagnostic performance of calf and thigh circumference in combination with SARC-F questionnaire in detecting sarcopenia. The aim of this study was to investigate the diagnostic performance of calf and thigh circumference in combination with SARC-F questionnaire compared to standard diagnostic methods of sarcopenia according to the Asian Working Group for Sarcopenia (AWGS) to predict sarcopenia in patient aged 60 years or older. METHODS: this cross-sectional study was conducted in Geriatric Clinic Cipto Mangunkusumo Hospital, Jakarta, Indonesia during April-June 2018. Analysis was performed using receiver operating characteristic (ROC) curve to determine the cut-off point as well as sensitivity (Sn), specificity (Sp), positive and negative predictive value (PPV and NPV), positive and negative likelihood ratio (LR+ and LR-) of calf and thigh circumference as an indicator of low muscle mass, and SARC-F questionnaire score to detect decreased muscle function. RESULTS: from 120 participants, there were 46 men (38.3%) and 74 women (61.7%). The combination of calf circumference with cut-off point below 34 cm in men and below 29 cm in women, thigh circumference below 49 cm in men and below 44 cm in women with SARC-F questionnaire score of ≥4 have Sn, Sp, PPV, NPV, LR+, and LR- of 15.79%; 99.01%; 75.00%; 86.21%; 15.95; and 0.85 respectively. CONCLUSION: combination of calf and thigh circumference with SARC-F questionnaire showed good diagnostic accuracy in predicting sarcopenia in elderly outpatients.