Abstract

Background: Sarcopenia in end-stage liver disease (ESLD) has been identified as a risk factor for increased mortality. Radiological parameters; psoas muscle area index (PMAI) & transverse psoas muscle thickness index (TPMTI) assess muscle quantity. While psoas muscle density index (PMDI) assesses muscle quality. Both identify muscle wasting, atrophy & myosteatosis.

Aim: The study evaluated ESLD phenotypes & their association with 1-year post-transplant mortality. The relationship between high PMAI/TPMTI & low PMDI, suggesting a possibility of larger but weaker muscles due to myosteatosis was investigated.

Methods: A total of 101 ESLD subjects were included. A retrospective analysis was conducted on 86 subjects with complete data. Clinical characteristics (age, PMAI, TPMTI, PMDI, CTP score, MELD score, BMI) were normalized using z-scores. Hierarchical & k-means clustering identified distinct phenotypes. Mortality rates across clusters were analyzed to identify high-risk groups.

Results: Five distinct phenotypes were identified. Cluster 1 represented individuals with an average age & high PMAI, TPMTI, BMI & low PMDI. CTP & MELD scores were close to average. Cluster 2 comprised young subjects with low PMAI, BMI, CTP, MELD & high PMDI. Cluster 3 was similar to Cluster 2, with younger subjects & baseline PMAI, PMDI, BMI & low TPMTI. CTP & MELD scores were high. Cluster 4 consisted of older individuals with high PMDI & low PMAI, TPMTI, BMI, CTP & MELD. Cluster 5 represented a baseline age group with baseline PMAI, high BMI & low PMDI, TPMTI, CTP & MELD. Cluster 1 had the highest mortality rate 41.7% & Cluster 2 had the lowest mortality rate (0%) compared to the overall mortality rate of 19.8%. Clusters 3, 4, & 5 had similar mortality rates of 17.4%, 17.9%, & 15.8%, respectively.

Conclusion: Clustering effectively identified high-risk phenotypes for sarcopenia & 1-year mortality in ESLD patients. Cluster 1, despite average age & baseline MELD, exhibited the highest mortality rate with low PMDI & high PMAI, TPMTI, & BMI. This suggests the possibility of myosteatosis contributing to mortality. Cluster 2 represented the lowest-risk group with younger patients having low BMI, MELD & high PMDI. These findings have implications for risk stratification & potential interventions to improve outcomes in this vulnerable patient population post-transplant.