Bioelectrical impedance analysis in the BaSAlt cohort-study: the phase angle as an additional parameter for sarcopenia quantification among German nursing home residents?

Key summary points: Aim: Can phase angle represents an additional parameter for quantifying sarcopenia among German nursing home residents? Findings: There is a limitation of the phase angle in differentiating between "confirmed/ severe sarcopenia" with "no sarcopenia" and "probable sarcopenia" groups among multimorbid nursing home residents in Germany. Message: Bioelectrical impedance analysis and determination of phase angle represent chances in the diagnostic of sarcopenia, but there is a limitation for differentiation in preliminary stage of sarcopenia among multimorbid NH residents. Purpose: 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). Methods: 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. Results: 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. Conclusions: 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. Trial registration: No. AZ A2.5.4-096_aa (Date of approval: July 2019). [ABSTRACT FROM AUTHOR]