Sarcopenia in the Cirrhotic Patient: Current Knowledge and Future Directions

Cirrhosis predisposes to abnormalities in energy, hormonal, and immunological homeostasis. Disturbances in these metabolic processes create susceptibility to sarcopenia or pathological muscle wasting. Sarcopenia is prevalent in cirrhosis and its presence portends significant adverse outcomes including the length of hospital stay, infectious complications, and mortality. This highlights the importance of identification of at-risk individuals with early nutritional, therapeutic and physical therapy intervention. This manuscript summarizes literature relevant to sarcopenia in cirrhosis, describes current knowledge, and elucidates possible future directions.

Lack of significant seasonal association between serum 25(OH)D concentration, muscle mass and strength in postmenopausal women from the D-FINES longitudinal study

The aim of the present study was to assess the seasonal relationship between serum 25(OH)D concentration, lean mass and muscle strength. This was a secondary data analysis of a subgroup of 102 postmenopausal women participating in the 2006-2007 D-FINES (Vitamin D, Food Intake, Nutrition and Exposure to Sunlight in Southern England) study. The cohort was assessed as two age subgroups: <65 years (n=80) and ≥65 years (n=22). Outcome measures included lean mass (DXA), muscle strength (handgrip dynamometry) and serum 25(OH)D concentration (enzymeimmunoassay). Derived outcomes included appendicular skeletal muscle mass (ASM) and relative appendicular skeletal muscle index (RASM). Sarcopenia status was assessed using the European Working Group on Sarcopenia in Older People 2018 criteria. Non-parametric partial correlation using BMI as a covariate was used to evaluate the study aims. There were no statistically significant associations between total lean mass, ASM or RASM and 25(OH)D in any group at any season. There was a trend for handgrip strength to be positively associated with serum 25(OH)D concentration. There was a trend showing a higher prevalence of sarcopenia in women ≥65 years. Sarcopenia status appeared transient for five women. In conclusion, the present study found no significant association between vitamin D status and functional indicators of musculoskeletal health, which were additionally not affected by season.

Alterations in Autophagy and Mammalian Target of Rapamycin (mTOR) Pathways Mediate Sarcopenia in Patients with Cirrhosis

Background and aims

The pathophysiology of sarcopenia in cirrhosis is poorly understood. We aimed to evaluate the histological alterations in the muscle tissue of patients with cirrhosis and sarcopenia, and identify the regulators of muscle homeostasis.

Methods

Computed tomography images at third lumbar vertebral level were used to assess skeletal muscle index (SMI) in 180 patients. Sarcopenia was diagnosed based on the SMI cut-offs from a population of similar ethnicity. Muscle biopsy was obtained from the vastus lateralis in 10 sarcopenic patients with cirrhosis, and the external oblique in five controls (voluntary kidney donors during nephrectomy). Histological changes were assessed by hematoxylin and eosin staining and immunohistochemistry for phospho-FOXO3, phospho-AKT, phospho-mTOR, and apoptosis markers (annexin V and caspase 3). The messenger ribonucleic acid (mRNA) expressions for MSTN, FoxO3, markers of ubiquitin-proteasome pathway (FBXO32, TRIM63), and markers of autophagy (Beclin-1 and LC3) were also quantified.

Results

The prevalence of sarcopenia was 14.4%. Muscle histology in sarcopenics showed atrophic angulated fibers (P = 0.002) compared to controls. Immunohistochemistry showed a significant loss of expression of phospho-mTOR (P = 0.026) and an unaltered phospho-AKT (P = 0.089) in sarcopenic patients. There were no differences in the immunostaining for annexin-V, caspase-3, and phospho-FoxO3 between the two groups. The mRNA expressions of MSTN and Beclin-1 were higher in sarcopenics (P = 0.04 and P = 0.04, respectively). The two groups did not differ in the mRNA levels for TRIM63, FBXO32, and LC3.

Conclusions

Significant muscle atrophy, increase in autophagy, MSTN gene expression, and an impaired mTOR signaling were seen in patients with sarcopenia and cirrhosis.

Sarcopenia in Cirrhosis: Fallout on Liver Transplantation

BACKGROUND

Liver transplantation (LT) is a game changer in cirrhosis. Poor muscle mass defined as sarcopenia may potentially upset the LT scoreboard.

AIM

To assess the prevalence and impact of sarcopenia on the intraoperative and early postoperative outcomes in Indian patients undergoing LT.

METHODS

Pre LT, single-slice routine computed tomography images at L3 vertebra of 115 LT recipients were analyzed, to obtain cross-sectional area of six skeletal muscles normalized for height in m² - skeletal muscle index (SMI; cm²/m²). SMI< 52.4 in males and <38.5 in females was called sarcopenia. The intraoperative, postoperative outcome parameters and 90-day mortality were compared between sarcopenics and nonsarcopenics.

RESULTS

Sarcopenia was found in 47.8% of patients [M (90.4%); age, 46.3 ± 10; BMI, 24.5 ± 4.3 kg/m2; child A:B:C = 1%:22%:77%; MELD, 20.6 ± 6.3; etiology alcohol: nonalchohol = 53%:47%; Charlson Comorbidity Index (CCI) > 3:≤3 = 56.5%:43.5%]. Sarcopenics vs. Nonsarcopenics; early postoperative complications: [sepsis, 49(89%) vs. 33(55%), P = 0.001; neurologic complications, 16(29.6%) vs. 5(8.8%), P = 0.040; Clavien-Dindo Classification ≥3-24 (43.6%):15 (25.4%),P = 0.041; ancillary parameters (days), duration of ventilation [median (range)] 1.5(1-3) vs. 1 (1-2), P = 0.021; intensive care unit (ICU) stay 12 (8-16) vs. 10 (8-12), P = 0.024; time to ambulation 9 (7-11) vs. 6 (5-7), P = 0.001; drain removal 18.7 ± 7.3 vs. 14.4 ± 6.2, P = 0.001; need for tracheostomy 5 (9%) vs. 0 (%), P = 0.017; preoperative prevalence of acute kidney injury, comorbidities and requirement for dialysis, intraoperative blood loss & inotropic support were significantly higher in sarcopenics. Ninety-day mortality was comparable between sarcopenics 5 (9.09%) and nonsarcopenics 4 (6.6%) P = 0.63. SMI (OR: 0.83; 95% CI: 0.71-0.97, P = 0.016; Acute on chronic liver failure (ACLF) presentation 12.5 (1.65-95.2), P = 0.015 and intraoperative blood loss 3.74 (0.96-14.6), P = 0.046 were predictors of 90-day mortality.

CONCLUSION

Almost 50% of LT recipients had sarcopenia, who had a higher incidence of postoperative sepsis, neurological complications, longer ICU stay and ventilatory support. Low SMI, ACLF presentation, and intraoperative blood loss were the independent predictors of early mortality.