Date of Award
Master of Science in Kinesiology
Segmental multi-frequency bioelectrical impedance analysis (SMF-BIA) has been shown to be a valid, more portable, and less expensive alternative to dual energy x-ray absorptiometry (DXA) for the measurement of appendicular lean mass (ALM) in several populations. However, few studies have examined the validity of SMF-BIA specifically among populations of older women classified as sarcopenic or dynapenic. The aim of this cross sectional study was to investigate the accuracy of SMF-BIA compared to the gold standard DXA for the measurement of ALM among sarcopenic and/or dynapenic older women. Physical function, ALM, strength, and anthropometric tests were performed to determine the presence of sarcopenia and/or dynapenia in a sample of 25 older (72.3 ± 4.6 years) women using established sarcopenia classification criteria. Estimation of ALM using SMF-BIA and DXA were performed under standardized testing conditions. Both techniques were administered within the same hour with participants adequately hydrated, fasted, following urine elimination, and while wearing hospital scrubs. A Pearson correlation coefficient was used to determine a relationship between the two methods for ALM and agreement between the two techniques was assessed using a Bland-Altman plot method. Statistical significance was set at p < 0.05. A significant and strong correlation was observed between the two techniques with a Pearson’s correlation coefficient of 0.88 (95% CI= 0.75 to 0.95; p < 0.001). The Bland-Altman plot showed a mean difference of 0.5 kg and an indication of overall agreement between techniques. However, SMF-BIA overestimated ALM for one participant (-2.9 kg, 95% CI= -3.76 to -2.03) and underestimated ALM for another participant (1.8 kg, 95% CI= 0.98 to 2.71) compared to DXA. The findings indicate overall agreement between SMF-BIA and DXA for the estimation of ALM among older women with characteristics of sarcopenia, but SMF-BIA may overestimate or underestimate ALM in some individuals. These data suggest that SMF-BIA may be an acceptable alternative to DXA for the assessment of ALM in older women with characteristics of sarcopenia.
Mahoney, Kayla, "Validation of Bioelectrical Impedance Analysis for the Measurement of Appendicular Lean Mass in Older Women" (2016). Open Access Master's Theses. Paper 845.