Prognostic Value of the Third Lumbar Skeletal Muscle Mass Index in Patients with Liver Cirrhosis and Ascites

Background & Aims: The objective nutritional assessment indicators, body mass index (BMI), upper arm muscle circumference (MAMC), and triceps skinfold thickness (TSF), are often limited due to ascites. This study investigated the prognostic value of the third lumbar vertebrae skeletal muscle mass index (L3 SMI) in addition to the objective nutritional evaluation indicators (BMI, MAMC and TSF) in patients with liver cirrhosis and ascites.

Methods: In this retrospective analysis, a total of 147 patients with liver cirrhosis and ascites were included. The L3 SMI, BMI, MAMC and TSF were detected in all patients. The severity of liver disease was assessed by the Model End-Stage Liver Disease (MELD) score and Child-Turcotte-Pugh (CTP) classification. These variables were compared between non-surviving and surviving patients who were classified according to 5-year mortality.

Results: Of the 147 patients, 62 (42.2%) died and 85 (57.8%) survived within 5 years. The L3 SMI of patients was significantly lower than that of the normal control group (39.58 ± 7.18 cm/m vs. 53.73 ± 7.92 cm/m,p < 0.001). The L3 SMI (OR 4.02; 95% CI 2.17-9.63; p < 0.001), MELD score (OR 2.11; 95% CI 1.12-4.13; p < 0.001) and CTP class (OR 2.69; 95% CI 1.09-5.06; p < 0.001) were independent predictive indicators of 5-year mortality. Furthermore, the performance of the two variables (L3 SMI and MELD) together (AUROC: 0.812) was significantly better than that of MELD alone (AUROC: 0.787) for prediction of 5-year mortality (p < 0.001).

Conclusion: Compared with MAMC, TSF and BMI, L3 SMI is an independent risk factor for 5-year mortality in patients with liver cirrhosis and ascites. Further nutritional intervention studies are needed to confirm the impact of the L3 SMI index on clinical outcomes.