Association Of L3 Skeletal Muscle Index And Prognosis In Patients With Liver Cirrhosis

BackgroundPatients with liver cirrhosis were often concomitant with malnutrition,and the degree of malnutrition is associated with its prognosis.The Child-Turcotte-Pugh classification,a subjective scoring system removed form Child-Pugh score,was used to assess liver function and predict prognosis in cirrhotic patients.Subsequent researches demonstrated the body mass index?BMI?,biceps circumference,waist circumference,skinfold thickness,serum albumin,serum prealbumin and subjective global assessment were relatively efficient to evaluate the nutritional status in cirrhotic patients.However,these indices were limited due to the potential influence of liver function reseve,ascites and complications.Emerging evidence suggests the L3 skeletal muscle index?L3 SMI?was associated with nutritional status and prognosis of patients.Sarcopenia was charicterized by progressive skeletal muscle depletion in mass and strength.Accumulated researches proved the pathogenesis of sarcopenia was related to aging,skeletal muscle disuse,endocrine dysfunction,chronic debilitating diseases,inflammation and nutritional deficiency and was a risk factor of adverse outcomes,such as physical disability,poor quality of life and even death.The Dual-energy X-ray scanning or bioelectrical impedance analysis?BIA?were used to evaluate the quality of skeletal muscle.However,the Dual-energy X-ray scanning was not routinely used in clinic and the accuracy of BIA was unsatisfied.Hence,an objected index could be obtained via CT and MRI imaging to estimate quality of skeletal muscle was widely applied in previous studies.The different components of our body,such as bones,muscles,fat and water,could be examined by CT and MRI scanning precisely.Previous study reported the difference between imaging acquired corss-sectional area and actual anatomical corss-sectional area was less than 2%and there is no difference between CT acquired corss-sectional area and MRI acquired corss-sectional area.In so doing,CT and MRI were considered as tools to examine the quality of skeletal muscle with high accuracy.In comparison with full-budy scan,the corss-sectional area of limbs or body in single slice CT was positively correlated with the total volume of skeletal muscle in our body.Notably,the L3 skeletal muscle area,without affecting by some factors?age,gender,height,weight,race,etc.?,showed the strongest correlation with total volume of skeletal muscle in our body^[8-11].Furthermore,the L3 SMI obtained by CT scanning was keeping consistent with skeletal muscle quality acquired by Dual-energy X-ray scanning.Thus,L3 SMI was recommeded by several guidelines for measuring the quality of skeletal muscle.L3 SMI was defined as L3 cross-sectional skeletal muscle area/height² and the L3 corss-sectional skeletal muscle including psoas muscle,erector spinae,lumbar muscle,transverse abdominis,external oblique muscle,and intra-abdominal oblique muscle.Recent reasearches focused on the association between prognosis of chronic liver diseases and cancer cachexia.In 2012,sarcopenia defined by L3 SMI?Male L3SMI<52.4cm2/m2,Female L3SMI<38.5 cm2/m2?was associated with more frequency of sepsis-related dath?22%vs 8%,P<.002? and higher mortality in patients with liver cirrhosis by Montano-Loza and colleagues?median survival:19±6 months vs compared with 34±11 months,P<0.005?.Furthermore,the sarcopenia defined by L3 SMI <50cm²/m² for men and <39 cm²/m² for women was proved with significantly higher wait-list mortality in patients with liver transplantation.To date,there is no diagnostic standard of sarcopenia defined by L3 SMI and the normative data of L3 SMI in China is scarcity.Part?:Noramtive data of L3 SMI in Chinese populationMethods:A total of 1396 out-patients in Shanghai east hospital were recuited from March 2018 to May 2018.The anthropometric parameters and abdominal CT imaging were recorded.The total area of L3 corss-sectional skeletal muscle was obtained by a software named Sliceomatic.As CT value was reliable for the identification of different tissue,the CT value of skeletal muscle was ranged from-29 to 150 hounsfield unit?HU?.The normative data of L3 SMI were built up stratified by age and gender.Results:According to the exclusion and inclusion criteria,a total of 911 healthy individuals?501 male and 422 female?were recruited with average age of 47.72±15.13.There were significant difference in anthropometric parameters?BMI,skinfold,grip strength,waist circumference,biceps circumference?and L3 body component indices between male and female with P<0.001.Age,gender,height,weight,biceps circumference and triceps skin-fold thickness were the influencing factors of L3 SMI.L3 SMI was decreased with increasing age and male had higher L3 SMI than female.Importantly,L3 SMI<42.18 cm²/m² for men and<31.68 cm²/m² for women,the definition for muscle depletion,were established as the standard for the diagnosis of sarcopenia in Chinese general individuals.Conclusion:We recommend L3 SMI<42.18 cm²/m² for men and<31.68 cm²/m² for women be used to define sarcopenia in Chinese general population.Part?:The association between L3 SMI and prognosis in patients with liver cirrhosisMethods:A total of 106 cirrhotic patients were retrospective enrolled in Shanghai Changzheng Hospital.The blood laboratory examination,abdominal CT indices,Child-Pugh score,MELD score,complication and prognostic outcomes were collected to ascertain the correlation with L3 SMI.The aimes were to ascertain the correlation of L3 SMI and other score system,evaluate the nutritional status according to the noramtive data of L3 SMI and ascertain the association of sarcopenia and prognosis in patients with liver cirrhosis.RESULTS:According to L3 SMI<42.18 cm²/m² for men and<31.68 cm²/m² for women,31.1% cirrhotic patients were diagnosed with sarcopenia,male of 18.8% amd female of 54%.In comparison with patients without sarcopenia,the sarcopenia patients were more prevalent in hepatic encephalopathy,spontaneous peritonitis,and hepatorenal syndrome.In addition,female cirrhotic patients with sarcopenia showed significantly higher motality in 1 year but no difference in male cirrhotic patients.Further prospective multicenter study should be carried out to explicit the association between sarcopenia and prognosis of patients with liver cirrhosis.Conclusion:L3 SMI is an efficient and objective index to reflect the quality of skeletal muscle.L3 SMI<42.18 cm2/m2 for men and<31.68 cm²/m² for women were considered as risk factors of poor prognosis in patients with liver cirrhosis.