Correlation Analysis Between Phase Angle And Sarcopenia In Elderly Patients

Objective:As China enters an aging society,sarcopenia is a prominent public health problem.Bioelectrical impedance analysis(BIA)is widely used in clinical practice as a simple measurement tool.The current research mainly focuses on the phase angle(Ph A)measured by BIA as an indicator of cell health,especially cell membrane integrity and cell function.Ph A has been proposed as a parameter to predict clinical outcomes and mortality of various diseases.However,there are still a few studies on the usefulness of this parameter for the diagnosis of sarcopenia.Therefore,the purpose of this study was to evaluate the relationship between Ph A and related parameters of sarcopenia composition,and to determine the cut-off value of Ph A in predicting sarcopenia.Methods:The clinical data of patients aged 60 and above in the Department of General Medicine and Geriatrics of the First Affiliated Hospital of Nanchang University from January 2022 to December 2022 were collected and analyzed.The Skeletal Muscle Mass Index(SMI)was calculated by Bioelectrical Impedance Analysis(Inbody 770).At the same time,Ph A and other body composition indicators could be measured,and sarcopenia was diagnosed by the 2019 Asian Working Group on Sarcopenia(AWGS2019).Firstly,the patients were divided into sarcopenia group and nonsarcopenia group.The differences of baseline data were compared,and the variables of independent risk factors were screened out.Multivariate logistic regression analysis was used to analyze the correlation between Ph A level and the risk of sarcopenia.Pearson correlation analysis was used to analyze the correlation between Ph A and the diagnostic indicators of sarcopenia.ROC curve was used to determine the best cut-off value of Ph A in predicting sarcopenia.Results:A total of 153 patients were included,with an average age of 70.87±9.15 years,including 67 cases of sarcopenia and 86 cases of non-sarcopenia.The Ph A level in the sarcopenia group was lower than that in the non-sarcopenia group(P < 0.001).Univariate logistic analysis was used to screen the risk factors of sarcopenia,and then the selected variables were unified into the multivariate logistic equation to finally obtain the independent risk factors of sarcopenia,NRS score(OR: 1.73;OR: 1.73;OR:1.73;OR: 1.73).95% CI: 1.04-3.06),degree of obesity(OR: 0.82;95% CI: 0.70-0.97),fat-free body mass index(OR: 4.15;95% CI: 1.10-18.01),muscle mass(OR: 0.04;95%CI: 0.00-0.84),Inbody score(OR: 0.75;95% CI: 0.63-0.86),phase angle(OR: 0.07;95% CI: 0.01-0.33),grip strength(OR: 0.63;95% CI: 0.51-0.76)were independent risk factors for sarcopenia in the elderly.The above seven independent risk factors were included in the model.ROC was drawn with sensitivity as the ordinate and(1-specificity)as the abscissa.The area under the phase angle ROC curve was 0.68(95%CI: 0.59-0.76),sensitivity 0.73,specificity 0.58,and the best cut-off value was 4.35°.The area under the ROC curve of male phase angle was 0.65(95% CI: 0.53-0.78),and the best cut-off value was 4.85°.The area under the ROC curve of female phase angle was 0.74(95% CI: 0.62-0.86),and the optimal cutoff value was 4.45°.Conclusion:PhA is positively correlated with skeletal muscle mass index and grip strength.Therefore,Ph A may be an effective indicator for detecting muscle mass and muscle strength in elderly inpatients,suggesting that it can be used as an easy indicator to measure muscle status and help to diagnose sarcopenia more accurately in the future.