Bioelectrical impedance analysis in the BaSAlt cohort-study: the phase angle as an additional parameter for...

Sarcopenia is characterized by the loss of muscle mass, strength, and physical functioning. The bioelectrical impedance analysis (BIA) is a simplify method for the measurement of muscle quantity and quality. But there is a lack of evidence in the interpretation of the muscle quality parameter phase angle (PhA), which was recommended by the European Working Group on Sarcopenia in Older People 2 (EWGSOP2). We hypothesize that the PhA shows differences between sarcopenia categorized groups and can be used as an additional parameter for sarcopenia quantification among residents of nursing homes (NH).

Based on EWGSOP2 specifications, 78 residents from five German NH was categorized into sarcopenia groups. Group comparisons with Kruskal-Wallis tests, Dunn-Bonferroni post-hoc-Tests, and correlations with Spearman coefficients were conducted with the muscle quality parameter PhA.

Significant group differences by Kruskal-Wallis test for PhA was detected (H = 8.150, p = 0.017). The Dunn-Bonferroni post-hoc-Test showed significant results by group comparison for "confirmed/ severe sarcopenia" (4.1° [3.1-5.0]) with "no sarcopenia" (4.6° [3.7-11.2]; p =0 .049) and "probable sarcopenia" (4.7° [3.4-13.5]; p = 0.016), respectively.

There is a limitation for differentiation in preliminary stage of sarcopenia among multimorbid NH residents by PhA. Moreover, further research for specific cut-off-values and the individual sarcopenia progression monitoring by PhA are needed.

No. AZ A2.5.4-096_aa (Date of approval: July 2019).