Diagnostic Value Of Different Skeleton Muscles In Elderly Patients With Chronic Obstructive Pulmonary Disease And Sarcopenia

Objective:To explore the diagnostic value of pectoral muscle,skeletal muscle of the first lumbar vertebra,quadriceps femoris,diaphragm and rectus abdominis on muscle quality in elderly patients with chronic obstructive pulmonary disease complicated with sarcopenia.Methods:In the pulmonary function testing room and respiratory medicine clinic of Sichuan Provincial People’s Hospital,60 to 90 year old subjects with stable COPD were recruited for lung function data,and mMRC symptom score and CAT score.Then the height,grip strength,walking speed,five sit-up tests(5 STS)and calf circumference(CC)were collected.The rectus abdominis muscle thickness(RAT),rectus femoris muscle thickness(FMT),rectus femoris muscle cross-sectional area(RF-CSA),quadriceps femoris muscle thickness(QFMT),diaphragm thickness functional residual capacity(TdiFRC),diaphragm thickness at total lung capacity(TdiTLC),diaphragm thickness at residual volume(TdiRV),diaphragm excursion during quiet breathing(Dq-DE)were measured by ultrasound.The diaphragm thickening fraction(DTF)was calculated.The cross-sectional area of pectoral muscle(PM CSA)and the cross-sectional area of skeletal muscle of the first lumbar vertebra(L1M CSA)were measured by chest CT.The appendicular skeletal muscle mass index(SMI)was measured by BIA.The patients were divided into low muscle mass(LMM)group and normal muscle mass(NMM)group according to the diagnostic criteria of Asian Sarcopenia Working Group.Pearson linear correlation analysis was made between muscle indexes measured by CT and ultrasound and SMI,and Spearman correlation analysis was used to analyze FEV1/FVC,mMRC score,CAT score and SMI,walking speed,grip strength and 5STS.ROC curve was used to evaluate the diagnostic value of muscle parameters in low muscle mass.Results:In this study 54 elderly patients with stable COPD and 33 patients with low muscle mass were included.There were 21 patients with normal muscle mass.Compared with the NMM group,BMI,body weight,walking speed,SMI,grip strength,CC,TdiRV,RAT,RF-CSA,QFMT,PM CSA,L1M CSA in the low muscle mass group were significantly lower(P<0.05).There was no significant difference in TdiFRC,TdiTLC,Dq-DE and DTF between the two groups(P>0.05).There was no significant correlation between TdiRV,TdiFRC,TdiTLC,Dq-DE,DTF and SMI(P>0.05).In the low muscle mass group,there was a strong positive correlation between CC,L1M CSA,RAT and SMI(r=0.727,0.650,0.629,P<0.01),and a moderate positive correlation between RF-CSA,PM CSA,QFMT and SMI.In the low muscle mass group,there was a significant negative correlation between CAT and walking speed(r=-0.453,P<0.01),and a significant positive correlation between mMRC and 5STS(r=0.461,P<0.01).FEV1/FVC,mMRC had no significant correlation with SMI,grip strength and walking speed.ROC curve analysis of the diagnosis of low muscle mass in elderly COPD male patients showed that the AUC values of PM CSA,QFMT,L1M CSA,RF-CSA and RAT were 0.850,0.830,0.802,0.722 and 0.684 respectively,and the susceptibility was 0.706,0.647,0.706 and 0.882 respectively,and the specificity was 0.889,0.963,0.852,0.519 and 0.778 respectively.The best cut-off values of PM CSA and QFMT with better diagnostic efficacy of CT and ultrasonic parameters were 38.46cm2 and 2.815cm respectively.Conclusions:In elderly patients with COPD and sarcopenia BMI,body weight,SMI,walking speed,grip strength,CC,TdiRV value were less than that of patients with normal muscle mass.Diaphragm thickness(TdiRV,TdiFRC,TdiTLC)and diaphragm function(Dq-DE,DTF)were not recommended as predictors of muscle mass in elderly COPD patients with sarcopenia.In elderly patients with COPD complicated with myometriosis,L1MCSA,RAT,RF-CSA,PMCSA,QFMT,CC were significantly positively correlated with muscle mass。CC was a good screening index to predict muscle mass in elderly patients with COPD complicated with sarcopenia.Muscle dysfunction had negative effects on the quality of life of patients with COPD,but has no significant relationship with lung function and dyspnea symptoms.In elderly male COPD patients,CT measurement of PMCSA is a good diagnostic index for low muscle mass,the susceptibility is 70.6%,the specificity is 88.9%,and the best cut-off value is 38.46cm2.Ultrasonic measurement of QFMT is a good diagnostic index for low muscle mass,the susceptibility is 64.7%,the specificity is 96.3%,and the best cut-off value is 2.815cm.