Skeletal Muscle Atrophy In Influenza A-associated Pneumonia And Clinical Association

[Backgroud]Influenza A-associated pneumonia causes a great number of deaths every year.There has been much recent interest in skeletal muscle changes,which is associated with the outcome of many diseases,in patients in severe condition.However,the study about the skeletal muscle atrophy is few,which is probably because of lack of the standard way to evaluate the skeletal muscle atrophy without abdominal CT.[Method]In the 1st section of this study,30 of influenza A-associated pneumonia patients in Nanjing Drum Tower Hospital,with both of thoracic and abdominal CT images were recruited first to establish the new way to evaluate the skeletal muscle atrophy in thoracic CT images by analyzing the relationship of the skeletal muscle atrophy between the 7th thoracic vertebra level(T7)and the standard level,the 3rd lumbar vertebra level(L3).In the 2nd section of this study,54 influenza A-associated pneumonia patients in Nanjing Drum Tower Hospital,with the first CT images performed on admission and the second CT images performed within 20 days after admission were included in this study.All of them were used to evaluate the skeletal muscle atrophy in thoracic CT images by analyzing the changes in areas and density of the skeletal muscles.[Results]1 In the 1st section of this study,The correlation of areas and density(HU values)of skeletal muscle between total skeletal muscle of T7 level(TSMT7)and both of psoas muscle of L3 level(PML3)and total skeletal muscle of L3 level(TSML3)were strong(p≤0.01).2 In the 2nd section of this study,Analysis showed a decrease of the areas of skeletal muscle in the 54 patients(p<0.001).The decrease of TSMT7 muscle area was associated with sex(male,p=0.018),age(≥60 year old,p=0.001)and CRP levels(≥100 mg/L,p<0.001).There are no changes in density(HU values)of skeletal muscle in all(p=0.949).The decrease of TSMT7 muscle areas was related to the increase of in-hospital mortality(p=0.004).[Conclusion]Skeletal muscle atrophy in influenza A-associated pneumonia can be evaluated by computed tomography.It mainly affects the skeletal muscle area instead of density,associated with age,gender and level of inflammation.It increases the in-hospital mortality.