BACKGROUND: To date, the accuracy of bio-impedance (BIA) to assess body composition & sarcopenia in persons aged 80 and over remains unclear.OBJECTIVE: We aimed to evaluate the agreement between dual energy X-ray absorptiometry (DXA) and BIA equations to determine lean mass, as well as their suitability to identify sarcopenia.DESIGN: 174 community dwelling well-functioning persons (83 women, 91 men) aged 80 and over were included. Appendicular lean mass (ALM) was predicted using BIA-based equations available in literature, and compared to DXA outcomes. Through cross-validation and stepwise multiple linear regression, a new ALM-formula was generated suitable for this population.RESULTS: Literature-based BIA equations systematically overestimated ALM. The new prediction formula that we propose for the 80+ is: ALM = 0,827+(0,19*Impedance Index)+(2,101*Sex)+(0,079*Weight); R2 = 0,888; SEE = 1,450 kg. Sarcopenia classification based on our new BIA equation for ALM showed better agreement with DXA (k ≥ 0,454) compared to literature-based BIA equations (k < 0,368).CONCLUSIONS: Despite the high correlation between both methods, literature-based BIA equations consistently overestimate ALM compared to DXA in persons aged 80 and over. We proposed a new equation for ALM, reaching higher agreement with DXA and thus improving the accuracy of BIA for this specific age group.
Vermeiren, S, Beckwée, D, Vella-Azzopardi, R, Beyer, I, Knoop, V, Jansen, B, Delaere, A, Antoine, A, Bautmans, I, Scafoglieri, A & Gerontopole Brussels Study group 2019, 'Evaluation of appendicular lean mass using bio impedance in persons aged 80+: A new equation based on the BUTTERFLY-study', Clinical Nutrition, vol. 38, no. 4, pp. 1756-1764. https://doi.org/10.1016/j.clnu.2018.07.029
Vermeiren, S., Beckwée, D., Vella-Azzopardi, R., Beyer, I., Knoop, V., Jansen, B., Delaere, A., Antoine, A., Bautmans, I., Scafoglieri, A., & Gerontopole Brussels Study group (2019). Evaluation of appendicular lean mass using bio impedance in persons aged 80+: A new equation based on the BUTTERFLY-study. Clinical Nutrition, 38(4), 1756-1764. https://doi.org/10.1016/j.clnu.2018.07.029
@article{d9f2e1f96fbe44aeacfb810f032a30da,
title = "Evaluation of appendicular lean mass using bio impedance in persons aged 80+: A new equation based on the BUTTERFLY-study",
abstract = "BACKGROUND: To date, the accuracy of bio-impedance (BIA) to assess body composition & sarcopenia in persons aged 80 and over remains unclear.OBJECTIVE: We aimed to evaluate the agreement between dual energy X-ray absorptiometry (DXA) and BIA equations to determine lean mass, as well as their suitability to identify sarcopenia.DESIGN: 174 community dwelling well-functioning persons (83 women, 91 men) aged 80 and over were included. Appendicular lean mass (ALM) was predicted using BIA-based equations available in literature, and compared to DXA outcomes. Through cross-validation and stepwise multiple linear regression, a new ALM-formula was generated suitable for this population.RESULTS: Literature-based BIA equations systematically overestimated ALM. The new prediction formula that we propose for the 80+ is: ALM = 0,827+(0,19*Impedance Index)+(2,101*Sex)+(0,079*Weight); R2 = 0,888; SEE = 1,450 kg. Sarcopenia classification based on our new BIA equation for ALM showed better agreement with DXA (k ≥ 0,454) compared to literature-based BIA equations (k < 0,368).CONCLUSIONS: Despite the high correlation between both methods, literature-based BIA equations consistently overestimate ALM compared to DXA in persons aged 80 and over. We proposed a new equation for ALM, reaching higher agreement with DXA and thus improving the accuracy of BIA for this specific age group.",
keywords = "Aged 80 and over, Bioelectrical impedance analysis, Body composition, Dual X-ray absorptiometry, Sarcopenia",
author = "S Vermeiren and D Beckw{\'e}e and R Vella-Azzopardi and I Beyer and V Knoop and B Jansen and A Delaere and A Antoine and I Bautmans and A Scafoglieri and {Gerontopole Brussels Study group} and Gina Rossi",
note = "Copyright {\textcopyright} 2018 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.",
year = "2019",
month = aug,
doi = "10.1016/j.clnu.2018.07.029",
language = "English",
volume = "38",
pages = "1756--1764",
journal = "Clinical Nutrition",
issn = "0261-5614",
publisher = "Churchill Livingstone",
number = "4",
}