Diagnostic value of whole-body phase angle and MNA-SF among the elderly with different phases of sarcopenia in community

Objective: To compare the diagnostic effects of PhA and MNA-SF in the different stages of sarcopenia, and to analyze the diagnostic value of the combined detection of PhA and MNA-SF for different stages of sarcopenia among the elderly community. Methods: The elderly aged 65 and above were enlisted during community outpatient service and their nutritional status was evaluated by MNA-SF scale. The composition with bioelectrical impedance analysis (BIA) was used to test PhA for identifying the diagnostic value of PhA and MNA-SF in different stages of sarcopenia among the elderly community and to analyze the diagnostic effect of combined detection of PhA and MNA-SF. Results: The AUC of PhA in the diagnosis of possible sarcopenia was 0.639, the sensitivity was 58.10%, the specificity was 66.67%, and the cut-off value was 4.5. The AUC of combined detection of PhA and MNA-SF for possible sarcopenia was 0.641, the sensitivity was 57.14%, and the specificity was 70.00%. The AUC of MNA-SF for the diagnosis of pre-sarcopenia was 0.805, the sensitivity was 66.67%, the specificity was 85.83%, and the cut-off value was 12. The AUC of combined detection of PhA and MNA-SF was 0.826, the sensitivity was 75.00%, and the specificity was 85.00%. PhA and MNA-SF all had the diagnostic value for sarcopenia, the AUC was 0.862,0.734, the sensitivity was 66.67% and 78.79%, the specificity was 92.50% and 65.00%, the cut-off value was 4.1 and 13. The AUC of combined detection of PhA and MNA-SF for sarcopenia was 0.879, the sensitivity was 81.82% and the specificity was 82.50%. Conclusion: The value of PhA alone or combined detection was higher than that of MNA-SF in the diagnosis of possible sarcopenia, the value of MNA-SF alone or combined detection was higher than that of PhA in the diagnosis of pre-sarcopenia. Compared to MNA-SF, the PhA had a higher value in the diagnosis of sarcopenia, which provides references for identifying patients with different stages of sarcopenia in the community.