The diagnostic performance of phase angle for sarcopenia among older adults: A systematic review and diagnostic meta-analysis.

Objective: Phase angle is a promising tool for diagnosing sarcopenia. This study aimed to summarize its diagnostic performance by performing a systematic review and meta-analysis.

Methods: We conducted a systematic search of PubMed, Web of Science, Embase, and Scopus. The Quality Assessment of Diagnostic Accuracy Studies, Version 2, was used to evaluate the quality of the studies. A bivariate random effects model was employed for data synthesis, and diagnostic performance was reported in terms of pooled sensitivity, specificity, and the area under the summary receiver operating characteristic curve (AUC). Additionally, meta-regression, subgroup analyses, and sensitivity analyses were performed.

Results: A total of 15 studies were included in this meta-analysis, involving 4,063 participants. The overall risk of bias in the included studies was high. The meta-analysis revealed that the pooled sensitivity and specificity across all studies were 0.74 [95 % confidence interval (CI): 0.71-0.78] and 0.75 (95 % CI: 0.70-0.79), respectively, with an AUC of 0.79 (95 % CI: 0.76-0.83). Meta-regression indicated that study design, country, population, sex-specificity, and age may influence the diagnostic performance of phase angle. The optimal diagnostic performance was observed in the cut-off interval of 4.20 to 4.50°.

Conclusion: The phase angle demonstrated moderate diagnostic performance for sarcopenia, and the possible cut-off interval is 4.20 to 4.50 °. However, large-scale, multicenter prospective studies are necessary to assess its clinical applicability at specific cut-off values.