Profile of plasma amino acids values as a predictor of sepsis in patients following living donor liver transplantation: Special reference to sarcopenia and postoperative early nutrition

Association between reduced muscle mass and poor prognosis of biliary sepsis

Sepsis is a life-threatening disease, contributing to significant morbidity and mortality. This study aimed to investigate the association between low muscle mass and the prognosis of patients with biliary sepsis, focusing on outcomes such as length of hospital stay (LOS), intensive care unit (ICU) admission, and in-hospital mortality. This retrospective, single-center, observational study included adult patients with biliary sepsis who visited the emergency department between January 2016 and December 2021. Low muscle mass was assessed using the psoas muscle index (PMI). Using computed tomography imaging, the area of both sides of the psoas muscle at the L3 level was measured, and the PMI, corrected by the patient's height was calculated. The primary outcome was in-hospital mortality, and the secondary outcomes were intensive care unit (ICU) admission, LOS, and 14-day mortality. A total of 745 patients were included in this study. Low muscle mass was defined as a PMI < 421 mm2/m2 for males and < 268 mm2/m2 for females with the lower quartile of PMI according to sex. The cohort was classified into sarcopenic (n = 189) and non-sarcopenic (n = 556) groups. There was a significant association between low muscle mass and in-hospital mortality (odds ratio, 3.81; 95% confidence interval, 1.08-13.47; p < 0.001), while there was no significant association between low muscle mass and ICU admission. In addition, the median LOS in the sarcopenic group (10 [7-14] days) was significantly longer than the median (8 [6-11] days) in the non-sarcopenic group. Low muscle mass was significantly associated with clinical outcomes, particularly in-hospital mortality and LOS, in patients with biliary sepsis.

Development and validation of a practical machine learning model to predict sepsis after liver transplantation

BACKGROUND

Postoperative sepsis is one of the main causes of mortality after liver transplantation (LT). Our study aimed to develop and validate a predictive model for postoperative sepsis within 7 d in LT recipients using machine learning (ML) technology.

METHODS

Data of 786 patients received LT from January 2015 to January 2020 was retrospectively extracted from the big data platform of Third Affiliated Hospital of Sun Yat-sen University. Seven ML models were developed to predict postoperative sepsis. The area under the receiver-operating curve (AUC), sensitivity, specificity, accuracy, and f1-score were evaluated as the model performances. The model with the best performance was validated in an independent dataset involving 118 adult LT cases from February 2020 to April 2021. The postoperative sepsis-associated outcomes were also explored in the study.

RESULTS

After excluding 109 patients according to the exclusion criteria, 677 patients underwent LT were finally included in the analysis. Among them, 216 (31.9%) were diagnosed with sepsis after LT, which were related to more perioperative complications, increased postoperative hospital stay and mortality after LT (all p < .05). Our results revealed that a larger volume of red blood cell infusion, ascitic removal, blood loss and gastric drainage, less volume of crystalloid infusion and urine, longer anesthesia time, higher level of preoperative TBIL were the top 8 important variables contributing to the prediction of post-LT sepsis. The Random Forest Classifier (RF) model showed the best overall performance to predict sepsis after LT among the seven ML models developed in the study, with an AUC of 0.731, an accuracy of 71.6%, the sensitivity of 62.1%, and specificity of 76.1% in the internal validation set, and a comparable AUC of 0.755 in the external validation set.

CONCLUSIONS

Our study enrolled eight pre- and intra-operative variables to develop an RF-based predictive model of post-LT sepsis to assist clinical decision-making procedure.

Can sarcopenia predict poor prognosis of sepsis due to acute cholecystitis?

AIM OF THE STUDY

As sepsis is a life-threatening disease, it is important to predict the prognosis in the early stages to establish treatment plans. This study aimed to investigate the association between sarcopenia, determined by the psoas muscle area, and the prognosis of sepsis due to acute cholecystitis.

METHODS

This retrospective single-center observational study included adult patients with sepsis due to acute cholecystitis who visited the emergency department between January 2016 and December 2021. The area of both sides of the psoas muscle at the L3 level was measured, and the psoas muscle index (PMI) corrected by the patient's height was calculated. Sarcopenia was determined based on PMI. The primary outcome was in-hospital mortality, and secondary outcomes were intensive care unit (ICU) admission, length of hospital stay (LOS), and 14-day mortality.

RESULTS

A total of 374 patients were included in this study. In this cohort, the lower quartile of PMI according to gender was set as the cut-off value to define sarcopenia. Sarcopenia was defined as PMI < 423 mm2/m2 for males and < 269 mm2/m2 for females. There were 94 patients in the sarcopenic group and 280 in the non-sarcopenic group. There was a significant association between sarcopenia and ICU admission (odds ratio [OR], 1.98; 95% confidence interval [CI], 1.05-3.76), and there was also a significant association between sarcopenia and in-hospital mortality (OR, 6.40; 95%CI, 1.13-36.09). Additionally, the median LOS in the sarcopenic group (11.5 (Cruz-Jentoft et al., 2010; Kawaguchi et al., 2019; Kim et al., 2017; Ritz et al., 2021; Cox et al., 2021; Lee et al., 2018; Okada et al., 2021; Prashanthi et al., n.d.; Amini et al., 2015; Fearon et al., 2011) days) was significantly longer than the median (8 (Rosenberg, 1989, 1997; Cruz-Jentoft et al., 2010; Kawaguchi et al., 2019; Kim et al., 2017; Ritz et al., 2021) days) in the non-sarcopenic group.

CONCLUSIONS

In patients with sepsis due to acute cholecystitis, sarcopenia was significantly associated with ICU admission, LOS, and in-hospital mortality.

Effect of Early Enteral Nutrition on Graft Loss After Living Donor Liver Transplantation: A Propensity Score Matching Analysis

BACKGROUND

This study aimed to elucidate the effect of early enteral nutrition on graft loss within 12 h after living-donor liver transplantation (LDLT) using propensity score-matching analysis and subsequently examine the risk factors for graft loss after LDLT.

METHODS

We retrospectively reviewed the data of 467 LDLT patients who were assigned to the early and non-early groups based on the optimal cutoff value of 12 h for the starting time of early enteral nutrition after LDLT to predict graft loss.

RESULTS

The 1-year graft survival rate of the early group before propensity score-matching was 92.1%, whereas the 1-year graft survival rate of the non-early group was 86.2%. There was no significant difference between the 2 groups (P = .067). The incidences of early allograft dysfunction (EAD), small-for-size graft (SFSG) syndrome, acute cellular rejection (ACR), and sepsis were not statistically different between the 2 groups (P = .12, .91, .46, and .056, respectively). After propensity score-matching, the 1-year graft survival rate of the early group was 94.4%, whereas the 1-year graft survival rate of the non-early group was 85.4% (P = .034). The incidences of EAD, SFSG syndrome, and ACR were not statistically different between the 2 groups (P = .43, .81, and .24, respectively). However, the incidence of sepsis was statistically different between the 2 groups (non-early: 10.7% vs early: 3.6%, P = .038).

CONCLUSION

Early enteral nutrition within 12 h after LDLT may contribute to better graft survival in LDLT patients by preventing sepsis.

Impact of sarcopenia on clinical outcomes for patients with resected hepatocellular carcinoma: a retrospective comparison of Eastern and Western cohorts

BACKGROUND

Patient fitness is important for guiding treatment. Muscle mass, as a reflection thereof, can be objectively measured. However, the role of East-West differences remains unclear. Therefore, we compared the impact of muscle mass on clinical outcomes after liver resection for hepatocellular carcinoma (HCC) in a Dutch [the Netherlands (NL)] and Japanese [Japan (JP)] setting and evaluated the predictive performance of different cutoff values for sarcopenia.

METHOD

In this multicenter retrospective cohort study, patients with HCC undergoing liver resection were included. The skeletal muscle mass index (SMI) was determined on computed tomography scans obtained within 3 months before surgery. The primary outcome measure was overall survival (OS). Secondary outcome measures were: 90-day mortality, severe complications, length of stay, and recurrence-free survival. The predictive performance of several sarcopenia cutoff values was studied using the concordance index (C-index) and area under the curve. Interaction terms were used to study the geographic effect modification of muscle mass.

RESULTS

Demographics differed between NL and JP. Gender, age, and body mass index were associated with SMI. Significant effect modification between NL and JP was found for BMI. The predictive performance of sarcopenia for both short-term and long-term outcomes was higher in JP compared to NL (maximum C-index: 0.58 vs. 0.55, respectively). However, differences between cutoff values were small. For the association between sarcopenia and OS, a strong association was found in JP [hazard ratio (HR) 2.00, 95% CI [1.230-3.08], P =0.002], where this was not found in NL (0.76 [0.42-1.36], P =0.351). The interaction term confirmed that this difference was significant (HR 0.37, 95% CI [0.19-0.73], P =0.005).

CONCLUSIONS

The impact of sarcopenia on survival differs between the East and West. Clinical trials and treatment guidelines using sarcopenia for risk stratification should be validated in race-dependent populations prior to clinical adoption.

Open Thoracic Drainage Followed by Proximal Splenic Artery Embolization for Massive Hydrothorax Before Living Donor Liver Transplantation

BACKGROUND

Hepatic hydrothorax is associated with postoperative infectious complications and mortality in patients undergoing living-donor liver transplantation (LDLT). Thus, preoperative management of massive hepatic hydrothorax is essential for improving the outcomes of LDLT. This study aimed to demonstrate our successful cases and strategy for treating massive hepatic hydrothorax.

METHODS

Our strategy for hepatic hydrothorax includes (a) mini-thoracotomy under general anesthesia for the drainage of hydrothorax, (b) preoperative hepatic inflow modulation by proximal splenic arterial embolization, and (c) nutritional and physical intervention to improve the general condition.

RESULTS

Two patients with massive hepatic hydrothorax were treated with our strategy. Both patients had end-stage liver disease secondary to primary biliary cholangitis. Their performance status deteriorated due to massive hydrothorax. After the intervention, their performance status significantly improved. After that, LDLTs with right lobe grafts were performed. The duration of the operation was 440 and 343 minutes, with an intraoperative blood loss of 1,700 and 1,600 g, respectively. Their postoperative courses were uneventful, and they were discharged on postoperative days 16 and 14.

CONCLUSION

Our pre-LDLT multimodal management strategy for massive hepatic hydrothorax, including preoperative open thoracic drainage, pre-LDLT portal inflow modulation, and nutritional intervention, improved the preoperative condition of patients undergoing LDLT, resulting in successful outcomes.

SCIATIC DENERVATION-INDUCED SKELETAL MUSCLE ATROPHY IS ASSOCIATED WITH PERSISTENT INFLAMMATION AND INCREASED MORTALITY DURING SEPSIS

ABSTRACT

Background: Patients with underlying skeletal muscle atrophy are likely to develop aggravated sepsis. However, no study has experimentally verified the association between the prognosis of sepsis and muscle atrophy, and the mechanism of aggravation of sepsis under muscle atrophy remains unclear. In this study, we investigated the effect of skeletal muscle atrophy induced by sciatic denervation (DN), an experimental muscle atrophy model, on sepsis prognosis. Methods: Skeletal muscle atrophy was induced by DN of the sciatic nerve in C57BL/6J male mice. Cecal ligation and puncture (CLP) was performed to induce sepsis. Results: The survival rates of the sham and DN groups 7 days after CLP were 63% and 35%, respectively, wherein an approximately 30% reduction was observed in the DN group ( P < 0.05, vs. sham-CLP). The DN group had a higher bacterial count in the blood 48 h after CLP ( P < 0.05, vs. sham-CLP). Notably, NOx (a metabolite of nitric oxide) concentrations in DN mice were higher than those in sham mice after CLP ( P < 0.05, vs. sham-CLP), whereas serum platelet levels were lower 48 h after CLP ( P < 0.05, vs. sham-CLP). In organ damage analysis, DN mice presented increased protein expression of the kidney injury molecule (KIM-1) and neutrophil gelatinase-associated lipocalin (NGAL), a kidney injury marker, after CLP (NGAL 48 h after CLP, P < 0.05, vs. sham-CLP; KIM-1 24 h after CLP, P < 0.01, vs. sham-CLP). Furthermore, nitro tyrosine levels in the kidneys of DN mice were higher 48 h after CLP compared with those in sham-CLP mice, indicating the accumulation of nitrative stress ( P < 0.05, vs. sham-CLP). Serum cytokine levels were increased in both groups after CLP, but decreased in the sham group 48 h after CLP and remained consistently higher in the DN group (tumor necrosis factor [TNF]-α: P < 0.05, sham-CLP vs. DN-CLP; interleukin (IL)-1β: P < 0.01, sham-CLP vs. DN-CLP; IL-6: P < 0.05, DN vs. DN-CLP; IL-10: P < 0.05, sham-CLP vs. DN-CLP). Conclusions: We verified that skeletal muscle atrophy induced by DN is associated with poor prognosis after CLP-induced sepsis. Importantly, mice with skeletal muscle atrophy presented worsening sepsis prognosis at late onset, including prolonged infection, persistent inflammation, and kidney damage accumulation, resulting in delayed recovery.

Nutritional Strategies to Manage Malnutrition and Sarcopenia following Liver Transplantation: A Narrative Review

Persisting or newly developed malnutrition and sarcopenia after liver transplant (LT) are correlated with adverse health outcomes. This narrative review aims to examine the literature regarding nutrition strategies to manage malnutrition and sarcopenia after LT. The secondary aims are to provide an overview of the effect of nutrition strategies on the incidence of infections, hospital length of stay (LOS), acute cellular rejection (ACR), and mortality after LT. Four databases were searched. A total of 25 studies, mostly of mid-high quality, were included. Six studies found a beneficial effect on nutritional parameters using branched-chain amino acids (BCAA), immunomodulating diet (IMD), or enteral nutrition (EN) whereas two studies using beta-hydroxy-beta-methylbutyrate (HMB) found a beneficial effect on muscle mass and function. Fourteen studies using pre- or pro-biotics, IMD, and EN were effective in lowering infection and six studies using IMD, BCAA or HMB reported reduced hospital LOS. Finally, four studies using HMB and vitamin D were effective in reducing ACR and one study reported reduced mortality using vitamin D after LT. In conclusion, nutritional intervention after LT has different beneficial effects on malnutrition, sarcopenia, and other advert outcomes. Additional large and well-constructed RCTs using validated tools to assess nutritional status and sarcopenia are warranted to ensure more robust conclusions.

Cachexia measured by bioelectrical impedance vector analysis and risk of infection in women with rheumatoid arthritis

Rheumatoid arthritis (RA) patients have a higher frequency of infections than the healthy population. The reason has yet to be explained but involves several factors, of which body composition and rheumatoid cachexia are often overlooked. This study aimed to evaluate whether patients with cachexia, measured by bioelectrical impedance vector analysis, are at an increased risk of developing infections compared with patients without cachexia. A secondary analysis of 186 women with RA enrolled in a randomized trial (ClinicalTrials.gov ID: NCT02900898, September 14, 2016) was completed. Medical records and phone calls were used to record infectious events diagnosed and treated during follow-up. Hazard ratios were calculated using Cox proportional hazard regression analysis, and a predictive model of infection was created. After 36 months of follow-up, 62 patients (26.7% non-cachectic and 44.3% cachectic, p < 0.01) developed at least one infectious event. The most common site of was the urinary tract, followed by the lungs and respiratory tract. The presence of cachexia (HR 1.90, 95% CI 1.15-3.13) and the use of glucocorticoids (HR 1.77, 95% CI 1.01-3.09) were associated with infection in univariate and multivariate models. Body mass index (BMI), smoking, and methotrexate use were not associated with a higher frequency of infections. The presence of cachexia and the use of glucocorticoids were identified as predictors of infections in a cohort of female RA patients. More extensive measurements of body composition should be performed beyond BMI in RA patients to better understand its impact and to prevent additional comorbidities and complications. Key Points • The presence of cachexia measured by bioelectrical impedance vector analysis was associated with infectious events in women with rheumatoid arthritis, whereas body mass index did not show an association. • Glucocorticoids were the only drug associated with a higher frequency of infection. None of the disease-modifying antirheumatic drugs, including methotrexate, showed an association.

Preoperative serum brain-derived neurotrophic factor as a predictive biomarker for sepsis after living-donor liver transplantation

AIM

Although the survival rate after living-donor liver transplantation (LDLT) is improving, sepsis still limits the prognosis. Immune dysfunction and sarcopenia are often observed in LDLT patients, and increase susceptibility to infection. Brain-derived neurotrophic factor (BDNF) is a myokine produced by immune cells and skeletal muscle. We aimed to determine whether serum BDNF could be a feasible biomarker for sepsis of LDLT patients.

METHODS

We measured serum samples from 124 patients who underwent LDLT and 9 healthy volunteers for BDNF. We examined its correlation with incidence rate of sepsis. To clarify the source of BDNF, we examined its expression in lymphocytes, skeletal muscle cells, and hepatocytes.

RESULTS

Patients who experienced sepsis showed worse short-term survival. Preoperative serum BDNF was lower in LDLT patients compared with healthy volunteers, and was also lower in Child-Pugh C compared with Child-Pugh A or B. Serum BDNF was inversely correlated with Model for End-Stage Liver Disease and controlling nutritional status (CONUT) scores, but had a weak positive correlation with skeletal muscle mass index (SMI). Multivariate analysis revealed that serum BDNF was independently associated with sepsis. Preoperative serum BDNF was a better predictor of sepsis in LDLT patients than CONUT score or SMI. Serum BDNF was positively correlated with lymphocyte counts, especially T cells. In vitro, T cells and skeletal muscle cells produced BDNF.

CONCLUSIONS

Preoperative serum BDNF could be a predictive biomarker for sepsis after LDLT, by reflecting the systemic condition including hepatic function, nutritional status, and immune status.

The impact of sarcopenia on short-term and long-term mortality in patients with septic shock

BACKGROUND

Despite medical advances, septic shock remains one of the main causes of high mortality in critically ill patients. Although sarcopenia is considered a predictor of mortality in septic shock patients, most studies have only investigated short-term mortality, and those on long-term prognosis are limited. We investigated the impact of sarcopenia on long-term mortality in a large patient population with septic shock.

METHODS

A retrospective cohort study comprising 905 patients with septic shock was conducted from 2008 to 2019. Sarcopenia was defined based on the measurement of the total abdominal muscle area, assessed using abdominal computed tomography scans. Thereafter, we stratified the patients into two groups-sarcopenia and non-sarcopenia groups-and compared the impact of sarcopenia on short-term (28 days) and long-term (1 year and overall) mortality using multivariable Cox proportional analysis.

RESULTS

A total of 905 patients were included, and the mean age was 65.7 ± 15.1 years. Among them, 430 (47.5%) patients were male and 407 (45.0%) had sarcopenia. We found that the 28 day, 1 year, and overall mortality rates in the sarcopenia group were significantly higher than those in the non-sarcopenia group (13.8% vs. 6.4%, P < 0.001; 41.8% vs. 21.7%, P < 0.001; 62.2% vs. 35.7%, P < 0.001, respectively). Univariable Cox analysis showed that the sarcopenia group had a significant association with the increase in each mortalities compared with the non-sarcopenia group (28 day mortality, hazard ratio (HR) = 2.230, 95% confidence interval (CI) [1.444-3.442], P < 0.001; 1 year mortality, HR = 2.189, 95% CI [1.720, 2.787], P < 0.001; overall mortality, HR = 2.254, 95% CI [1.859, 2.734], P < 0.001). Multivariable Cox analysis showed that both the short-term and long-term mortality rates remained significantly higher in the sarcopenia group than in the non-sarcopenia group, even after adjusting for confounding variables (28 day mortality, HR = 2.116, 95% CI [1.312, 3.412], P = 0.002; 1 year mortality, HR = 1.679, 95% CI [1.291, 2.182], P < 0.001; overall mortality, HR = 1.704, 95% CI [1.381, 2.102], P < 0.001).

CONCLUSIONS

Sarcopenia was associated with both short-term and long-term mortality in patients with septic shock. In clinical settings, close attention should be paid to these patients for both short-term and long-term outcomes.

Survival Outcome of Sepsis in Recipients of Solid Organ Transplant

Sepsis is a complex disease stemming from a dysregulated immune response toward an infectious agent. In transplantation, sepsis remains one of the leading causes of morbidity and mortality. Solid organ transplant recipients have impaired adaptive immunity due to immunosuppression required to prevent rejection. Immunosuppression has unintended consequences, such as increasing the risk of infections and sepsis. Due to its high morbidity and mortality, early detection of sepsis is paramount to start aggressive treatment. Several biomarkers or combination of biomarkers of sepsis have emerged in the last decade, but they are not dependable for early diagnosis or for outcome prognosis.

Impact of sarcopenia in infants with liver transplantation for biliary atresia

While sarcopenia is an important predictor of LT outcomes in adults, few studies have examined the association of sarcopenia with LT outcomes in pediatric patients. We investigated the clinical influence of sarcopenia on the post-transplant outcomes in infants with BA. To define sarcopenia in infants, the cross-sectional area of the tPMA in 93 healthy control infants was measured by computed tomography. Sarcopenia was defined as a tPMA lower than two standard deviations below the mean of healthy control infants. Eighty-nine infants with BA with a median age at LT of 7.6 months old were enrolled. The clinical characteristics and outcomes of LT were verified in the sarcopenia group (n = 21) and non-sarcopenia group (n = 68). The sarcopenia group had a significantly longer operation time and greater blood loss during LT than the non-sarcopenia group (P = .03 and 0.02). The incidence of portal vein stenosis and post-operative bloodstream infection was also significantly higher in the sarcopenia group than in the non-sarcopenia group (23.8% vs 4.4%, P = .02 and 28.6% vs 10.3%, P = .04, respectively). The total length of hospital stay did not differ significantly. The 1-year patient and graft survival rates tended to be lower in the sarcopenia group than in the non-sarcopenia group (90.5% vs 98.5%, P = .07 and 85.7% vs 97.1%, P = .05, respectively). Sarcopenia in infants with BA may be associated with the patient survival and serve as an effective marker for post-operative outcomes of LT.

Signatures and Clinical Significance of Amino Acid Flux in Sarcopenia: A Systematic Review and Meta-Analysis

BACKGROUND

Dysregulation of amino acids is closely linked to the initiation and progression of sarcopenia. We summarized recent advancements in the studies of amino acid profiles in sarcopenia and systematically presented the clinical significance of amino acid flux in sarcopenia.

METHODS

We systematically searched in MEDLINE, EMBASE, and Cochrane library from inception to June 1, 2021 to capture all studies examining metabolomics of sarcopenia. We used the following keywords: sarcopenia, metabonomics, metabolomics, amino acid profile, and mass spectrometry. Original articles comparing amino acid patterns between persons with and without sarcopenia were included. Two independent investigators independently completed title and abstract screening, data extraction, and quality evaluation. We used a random effects model to examine the association between amino acids levels and sarcopenia. Sensitivity analyses restricted the analyses to studies in which muscle mass was measured by bioelectrical impedance analysis. Study quality was evaluated according to the Agency for Healthcare Research and Quality (AHRQ) checklist.

RESULTS

The systematic research yielded six eligible articles, comprising 1,120 participants. Five studies used muscle mass in combination with physical performance and/or muscle strength as the criteria to diagnose sarcopenia, while one study used muscle mass as a diagnostic criterion alone. We found that the concentrations of branched-chain amino acids leucine (standardized mean difference [SMD] -1.249; 95% confidence interval [CI]: -2.275, -0.223, P = 0.02, I² = 97.7%), isoleucine (SMD -1.077; 95% CI: -2.106, -0.049, P = 0.04, I² = 97.8%), and aromatic amino acid tryptophan (SMD -0.923; 95% CI: -1.580, -0.265, P = 0.01, I² = 89.9%) were significantly reduced in individuals with sarcopenia. Study results were robust in sensitivity analysis.

CONCLUSIONS

The homeostasis of amino acids is critical to maintaining muscle health. The profiles of amino acids might be useful biomarkers for the characterization of sarcopenia. Future studies are warranted to study the clinical significance of amino acids in the diagnosis and treatment of sarcopenia.

Influence of Preoperative Muscle Mass Assessed by Computed Tomography on Prognosis After Liver Transplantation

BACKGROUND

Sarcopenia (SP) and preoperative muscle mass are independent predictive factors for short- and long-term outcome of liver transplantation.

OBJECTIVE

To assess the influence of muscle mass index (MMI) and preoperative SP on the prognosis of patients who underwent liver transplantation in our hospital.

METHODS

Ninety-seven patients who underwent liver transplantation in the Regional University Hospital of Málaga from September 2013 to March 2016 were analyzed. SP was determined based on the MMI, as assessed by psoas muscle area at the L4 level measured by computed tomography (CT), with adjustment for patient sex. Two cohorts were differentiated: 54 patients without SP and 42 patients with SP. Postoperative complications, graft survival, and patient survival were assessed. A 3-year follow-up was carried out.

RESULTS

Recipient characteristics were similar in both cohorts, except for MMI ± SD (group without SP: 94.03 ± 15.43 cm2/m2 vs group with SP: 56.99 ± 13.59 cm2/m2; P = .001). The incidence of postoperative complications (Clavien ≥ 3) in patients with and without SP was 39.5% and 24.1%, respectively (P = .08). SP was not associated with poorer long-term graft or patient survival.

CONCLUSIONS

SP, determined by preoperative measurement of MMI, was identified as a predictive factor associated with a higher incidence of postoperative complications. Since MMI can be easily determined by CT, it should be assessed in all candidates for liver transplantation.

Progressive loss of muscle mass could be an adverse prognostic factor of 28-day mortality in septic shock patients

A decrease in skeletal muscle mass has been shown to increase hospital mortality. Nevertheless, little is known about the association between progressive muscle loss over time and clinical outcomes. We aimed to evaluate whether progressive loss of muscle mass in septic shock patients was associated with mortality. We reviewed prospectively enrolled registry of septic shock which had 817 consecutive patients. Of these, 175 patients who had computed tomography (CT) at a time of admission as well as 3-6 months prior to admission were included. Between these two CTs, the change in total abdominal muscle area index (TAMAI) was evaluated for progressive muscle loss. The change in TAMAI was higher in the non-survivors (-7.6 cm²/m², 19.0% decrease) than the survivors (-4.0 cm²/m², 10.5% decrease) with statistical significance (p = 0.002). Multiple logistic regression showed that the patients who had more than a 6.4 cm²/m² (16.7%) reduction of TAMAI had a 4.42-fold higher risk for mortality at 28 days (OR, 4.42; 95% CI, 1.41-13.81, p = 0.011). Our study suggested that progressive loss of muscle mass might be a useful prognostic factor for septic shock patients. This implication will need to be further explored in future prospective studies.

Frailty, Sarcopenia, and Malnutrition in Cirrhotic Patients

Sarcopenia, frailty, and malnutrition are prevalent complications in patients with end-stage liver disease (ESLD) and are associated with increased risk of morbidity and mortality. It is valuable to measure nutritional status, sarcopenia, and frailty over time in order to create interventions tailored to individuals with ESLD. Evaluating sarcopenia and frailty in patients with ESLD is challenging. Further work is needed to perfect these assessments so that clinicians can incorporate these assessments into their decision-making and management plans for cirrhotic patients.

A reliable LC-MS/MS method for the quantification of natural amino acids in mouse plasma: Method validation and application to a study on amino acid dynamics during hepatocellular carcinoma progression

A simple and fast LC-MS/MS method was developed and validated for simultaneous quantification of 20 proteinogenic l-amino acids (AAs) in a small volume (5 μL) of mouse plasma. Chromatographic separation was achieved on an Intrada Amino Acid column within 13 min via gradient elution with an aqueous solution containing 100 mM ammonium formate and an organic mobile phase containing acetonitrile, water and formic acid (v:v:v = 95:5:0.3), at the flow rate of 0.6 mL/min. Individual AAs and corresponding stable-isotope-labeled AAs internal standards were analyzed by multiple reaction monitoring (MRM) in positive ion mode under optimized conditions. Method validation consisted of linearity, sensitivity, accuracy and precision, recovery, matrix effect, and stability, and the results demonstrated this LC-MS/MS method as a specific, accurate, and reliable assay. This LC-MS/MS method was thus utilized to compare the dynamics of individual plasma AAs between healthy and orthotopic hepatocellular carcinoma (HCC) xenograft mice housed under identical conditions. Our results revealed that, 5 weeks after HCC tumor progression, plasma l-arginine concentrations were significantly decreased in HCC mice while l-alanine and l-threonine levels were sharply increased. These findings support the utilities of this LC-MS/MS method and the promise of specific AAs as possible biomarkers for HCC.

Rapid Determination of Amino Acids of Nitraria tangutorum Bobr. from the Qinghai-Tibet Plateau Using HPLC-FLD-MS/MS and a Highly Selective and Sensitive Pre-Column Derivatization Method

Amino acids are indispensable components of living organisms. The high amino acid content in Nitraria tangutorum Bobr. fruit distinguishes it from other berry plants and is of great significance to its nutritional value. Herein, using 10-ethyl-acridine-3-sulfonyl chloride as a fluorescent pre-column labeling reagent, a method for the efficient and rapid determination of amino acid content in N. tangutorum by pre-column fluorescence derivatization and on-line mass spectrometry was established and further validated. The limits of detection (signal-to-noise ratio = 3) were between 0.13 and 1.13 nmol/L, with a linear coefficient greater than 0.997 and a relative standard deviation between 1.37% and 2.64%. In addition, the method required a short analysis time, separating 19 amino acids within 20 min. Subsequently, the method was used to analyze the amino acid content of Nitraria tangutorum Bobr. from tissues retrieved from seven regions of the Qinghai-Tibet Plateau. Nitraria tangutorum Bobr. was shown to contain a large amount of amino acids, with the total content and main amino acid varying between the different tissues. This research supports the nutritional evaluation, quality control, and development and utilization of Nitraria tangutorum Bobr.

Sarcopenia in Liver Transplantation

PURPOSE OF REVIEW

Sarcopenia is highly prevalent in end-stage liver disease (ESLD) patients and has been linked to poor outcomes on the wait list and post-transplantation. This current perspectives article reviews the ongoing challenges to define sarcopenia in ESLD patients, describes associations of sarcopenia with wait-list and post-transplantation outcomes, and provides summarized data on efforts to prevent and treat sarcopenia through novel interventions.

RECENT FINDINGS

Supervised exercise programs improve muscle strength, but muscle mass outcomes are limited by short study follow-up times. Branched chain amino acid supplementation may ameliorate sarcopenia in ESLD patients, but studies limited by low participant numbers and confounding. Myostatin inhibition shown to improve sarcopenia in elderly, frail patients; further study needed in ESLD patients. Correction of low testosterone improves sarcopenia in male ESLD patients.

SUMMARY

Recent literature supports sarcopenia as an independent risk factor for poor outcomes in ESLD patients. Ongoing study is limited by poor standardization of sarcopenia definition and relevant muscle-mass cutoffs. Supervised exercise programs should be encouraged for all ESLD patients. More advanced therapies require further clinical investigation before their widespread use.

Loss of paraspinal muscle mass is a gender-specific consequence of cirrhosis that predicts complications and death

BACKGROUND

Loss of skeletal muscle mass is a recognised complication with a prognostic impact in patients with cirrhosis.

AIM

To explore in a retrospective analysis which muscle compartment most reliably predicts the occurrence of cirrhosis-associated complications and if there are gender-related differences.

METHODS

795 patients with cirrhosis listed for liver transplantation between 2001 and 2014 met the inclusion and exclusion criteria including an abdominal CT scan (±200). Controls were 109 patients who underwent a CT scan after polytrauma. The paraspinal muscles index (PSMI), the abdominal wall muscles index (AWMI) and its combination skeletal muscle index (SMI) were assessed at L3/L4, normalised to the height (cm² /m² ).

RESULTS

62.0% of patients with cirrhosis had alcoholic liver disease, and 70.6% were male. As compared to controls, a reduction in PSMI and SMI but not AWMI was associated with high model of end-stage liver disease (MELD) score, high Child-Pugh class, and the presence or history of cirrhosis-associated complications in males but not females. PSMI independently predicted the occurrence of bacterial infections (HR 0.932), spontaneous bacterial peritonitis (HR 0.901), hepatic encephalopathy (HR 0.961), and hepatorenal syndrome (HR 0.946) by multivariate Cox regression analysis in a gender-independent manner. Post-transplant survival was not associated with the PSMI; neither AWMI nor SMI predicted any clinical endpoints.

CONCLUSIONS

This study links muscle wasting in patients with cirrhosis predominantly to males. However, the presence of a low PSMI mass is a gender-independent predictor of developing cirrhosis-associated complications and death. Scores combining the MELD with muscle parameters should be re-validated by utilizing the PSMI.

Early enteral nutrition is associated with reduced in-hospital mortality from sepsis in patients with sarcopenia

PURPOSE

To determine whether the association of early enteral nutrition (EEN) with mortality from sepsis differs between patients with and without sarcopenia.

MATERIALS AND METHODS

We retrospectively reviewed septic patients treated at our centre between January 2010 and August 2017. The skeletal muscle area (SMA) at the level of the third lumbar vertebra was measured with CT on admission, and sarcopenia was defined as SMA < 80% of the predicted value. Patients were divided into two subgroups (sarcopenic and non-sarcopenic patients), and in-hospital mortality was compared in patients treated with and without EEN within each subgroup. We used logistic regression to examine factors associated with in-hospital mortality in each subgroup.

RESULTS

EEN was administered to 35/91 sarcopenic patients and 43/100 non-sarcopenic patients. In-hospital mortality did not differ between non-sarcopenic patients with EEN and those without EEN (16% vs 16%, P = 0.947), but was significantly lower in sarcopenic patients with EEN than in those without EEN (9% vs 34%, P = 0.005). Logistic regression showed that EEN was independently associated with reduced in-hospital mortality in sarcopenic patients (OR 0.18, 95% CI 0.05-0.71, P = 0.014), but not in non-sarcopenic patients.

CONCLUSIONS

EEN may be more beneficial in sarcopenic patients.

Risk Factors for Sepsis Based on Sepsis-3 Criteria after Orthotopic Liver Transplantation

Sepsis is a common complication of solid organ transplant procedures and, in particular, can affect the prognosis of orthotopic liver transplantation (OLT). This retrospective study determined the pre-, peri-, and postoperative risk factors for sepsis after OLT, using as reference the 2016 Third International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3). Pre-, peri-, and postoperative clinical data of the sepsis-positive (n = 85) and sepsis-negative (n = 41) groups were analyzed for potential risk factors of OLT-related sepsis. The sepsis-positive patients had a significantly higher rate of dialysis (49.4%), longer time under mechanical ventilation (1.5 d), higher hospitalization costs (0.41 million RMB), and worse survival rate (68.5%), compared with the sepsis-negative patients (4.8%, 1 d, 0.30 million RMB, and 73.1%, resp.). The multivariate logistic analysis identified the following as risk factors for OLT-related sepsis: preoperative Child-Pugh grade C (OR 10.43; 95% CI 2.081–52.292; P = 0.004), preoperative hypercalcemia (OR 6.372; 95% CI 1.693–23.98; P = 0.006), and perioperative acidosis (OR 6.364; 95% CI 1.196–33.869; P = 0.030). Patients with preoperative Child-Pugh grade C, preoperative hypercalcemia, or perioperative acidosis are at higher risk for developing sepsis after OLT. When any of these problems occur, timely sepsis management should be planned.

Muscle Mass Depletion Associated with Poor Outcome of Sepsis in the Emergency Department

Background/Aims: Muscle mass depletion has been suggested to predict morbidity and mortality in various diseases. However, it is not well known whether muscle mass depletion is associated with poor outcome in sepsis. We hypothesized that muscle mass depletion is associated with poor outcome in sepsis. Methods: Retrospective observational study was conducted in an emergency department during a 9-year period. Medical records of 627 patients with sepsis were reviewed. We divided the patients into 2 groups according to 28-day mortality and compared the presence of muscle mass depletion assessed by the cross-sectional area of the psoas muscle at the level of the third lumbar vertebra on abdomen CT scans. Univariate and multivariate logistic regression analyses were conducted to examine the association of scarcopenia on the outcome of sepsis. Results: A total of 274 patients with sepsis were finally included in the study: 45 (16.4%) did not survive on 28 days and 77 patients (28.1%) were identified as having muscle mass depletion. The presence of muscle mass depletion was independently associated with 28-day mortality on multivariate logistic analysis (OR 2.79; 95% CI 1.35–5.74, p = 0.01). Conclusions: Muscle mass depletion evaluated by CT scan was associated with poor outcome of sepsis patients. Further studies on the appropriateness of specific treatment for muscle mass depletion with sepsis are needed.

Acute Sarcopenia Secondary to Hospitalisation - An Emerging Condition Affecting Older Adults

There has been increasing interest and research into sarcopenia in community-dwelling older adults since the European Working Group on Sarcopenia in Older People (EWGSOP) agreed a consensus definition in 2010. Sarcopenia has been defined as loss of muscle mass with loss of muscle function (strength or physical performance), with measurements two Standard Deviations (SDs) below the mean of a young reference population. This definition does not necessitate longitudinal measurements, or the absence of acute illness and diagnosis can be made from single measurements. We hypothesise that hospitalisation, due to a combination of acute inflammatory burden and muscle disuse, leads to an acute decline in muscle mass and function and may lead to some individuals meeting criteria for sarcopenia, acutely, based on the EWGSOP definition. This may be partially recoverable or may lead to increased risk of developing sarcopenia long-term. We have denoted the term “acute sarcopenia” to refer to acute loss of muscle mass and function associated with hospitalisation. This review discusses some of the current available research in this context and also identifies some of the knowledge gaps and potential areas for future research.

Sarcopenia in Liver Disease: Current Evidence and Issues to Be sResolved

Sarcopenia is a common clinical symptom in aging and patients with wasting diseases, characterized by a decreased skeletal muscle mass. As a consequence of lifestyle change, the nonalcoholic fatty liver disease (NAFLD) presents a rising trend. In the past three decades, increasing evidence has proved that sarcopenia is related to NAFLD. In this chapter, we will summarize the emerging evidence of the predictive role of sarcopenia in NAFLD and review the diagnosis value, feasible mechanism, and therapy strategies of sarcopenia in NAFLD. Sarcopenia is a potential risk factor for NAFLD, and targeting sarcopenia can benefit NAFLD to some extent.

Amino acid supplements and metabolic health: a potential interplay between intestinal microbiota and systems control

Dietary supplementation of essential amino acids (EAAs) has been shown to promote healthspan. EAAs regulate, in fact, glucose and lipid metabolism and energy balance, increase mitochondrial biogenesis, and maintain immune homeostasis. Basic science and epidemiological results indicate that dietary macronutrient composition affects healthspan through multiple and integrated mechanisms, and their effects are closely related to the metabolic status to which they act. In particular, EAA supplementation can trigger different and even opposite effects depending on the catabolic and anabolic states of the organisms. Among others, gut-associated microbial communities (referred to as gut microbiota) emerged as a major regulator of the host metabolism. Diet and host health influence gut microbiota, and composition of gut microbiota, in turn, controls many aspects of host health, including nutrient metabolism, resistance to infection, and immune signals. Altered communication between the innate immune system and the gut microbiota might contribute to complex diseases. Furthermore, gut microbiota and its impact to host health change largely during different life phases such as lactation, weaning, and aging. Here we will review the accumulating body of knowledge on the impact of dietary EAA supplementation on the host metabolic health and healthspan from a holistic perspective. Moreover, we will focus on the current efforts to establish causal relationships among dietary EAAs, gut microbiota, and health during human development.

Increased plasma proline concentrations are associated with sarcopenia in the elderly

Background and purpose

Metabolome analyses have shown that plasma amino acid profiles reflect various pathological conditions, such as cancer and diabetes mellitus. It remains unclear, however, whether plasma amino acid profiles change in patients with sarcopenia. This study therefore aimed to investigate whether sarcopenia-specific changes occur in plasma amino acid profiles.

Methods

A total of 153 community-dwelling and seven institutionalized elderly individuals (56 men, 104 women; mean age, 77.7±7.0 years) were recruited for this cross-sectional analysis. We performed a comprehensive geriatric assessment, which included an evaluation of hand grip strength, gait speed, muscle mass and blood chemistry, including the concentration of 18 amino acids.

Results

Twenty-eight of the 160 participants met the criteria for sarcopenia established by the Asian Working Group on Sarcopenia in Older People. Univariate analysis revealed associations between the presence of sarcopenia and a higher plasma concentration of proline and glutamine, lower concentrations of histidine and tryptophan. Multivariable analysis revealed that a higher concentration of proline was the only variable independently associated with sarcopenia.

Conclusions

The plasma concentration of proline may be useful for understanding the underlying pathophysiology of sarcopenia.

Simple Age Specific Cutoff Value for Sarcopenia Evaluated by Computed Tomography

Objective: Until now, cutoff values of low skeletal muscle mass using computed tomography (CT) were driven by optimal stratification to predict mortality in cancer patients. The aim of the present study was to investigate the simple, age-specific, cutoff value of low skeletal muscle mass by CT in healthy adults. Design: This is a retrospective, observational, single-center study. Setting: This study was performed in the health screening department of a university-affiliated hospital during a 10-year period. Patients: Medical records of 1,422 patients presenting to the health screening department were reviewed. Cross-sectional area of psoas muscle at the level of the third lumbar vertebra on abdominal CT was measured and adjusted by height (mm2/m2). This value (psoas muscle index [PMI]) was assumed to represent whole skeletal muscle mass. We divided the patients according to age, sex, and defined cutoff value of low skeletal muscle mass as 2 SDs below the mean. Intervention: None. Measurements and Main Results: Among 1,422 patients, 550 patients (38.6%) were male. The mean PMI was 896.60 (mm2/m2) for men and 570.54 (mm2/m2) for women. Cutoff values of PMI for men were 592.3 mm2/m2 for 20-39 years, 474.0 mm2/m2 for 40-49 years, 422.2 mm2/m2 for 50-59 years, 374.4 mm2/m2 for 60-69 years, and 331.5 mm2/m2 for 70-89 years. The values for women were 399.9 mm2/m2 for 20-39 years, 287.7 mm2/m2 for 40-49 years, 242.5 mm2/m2 for 50-59 years, 220.4 mm2/m2 for 60-69 years, and 147.6 mm2/m2 for 70-89 years. Conclusions: Cutoff values of low skeletal muscle mass using CT differed in healthy adults as age increased. Further studies on the effect of sarcopenia intervention using this cutoff value are needed.

Recent trends in analytical methods for the determination of amino acids in biological samples

Amino acids are widely distributed in biological fluids and involved in many biological processes, such as the synthesis of proteins, fatty acids, and ketone bodies. The altered levels of amino acids in biological fluids have been found to be closely related to several diseases, such as type 2 diabetes, kidney disease, liver disease, and cancer. Therefore, the development of analytical methods to measure amino acid concentrations in biological samples can contribute to research on the physiological actions of amino acids and the prediction, diagnosis and understanding of diseases. This review describes the analytical methods reported in 2012-2016 that utilized liquid chromatography and capillary electrophoresis coupled with ultraviolet, fluorescence, mass spectrometry, and electrochemical detection. Additionally, the relationship between amino acid concentrations and several diseases is also summarized.

A multicenter study to define sarcopenia in patients with end-stage liver disease

Sarcopenia is associated with increased wait-list mortality, but a standard definition is lacking. In this retrospective study, we sought to determine the optimal definition of sarcopenia in end-stage liver disease (ESLD) patients awaiting liver transplantation (LT). Included were 396 patients newly listed for LT in 2012 at 5 North American transplant centers. All computed tomography scans were read by 2 individuals with interobserver correlation of 98%. Using image analysis software, the total cross-sectional area (cm² ) of abdominal skeletal muscle at the third lumbar vertebra was measured. The skeletal muscle index (SMI), which normalizes muscle area to patient height, was then calculated. The primary outcome was wait-list mortality, defined as death on the waiting list or removal from the waiting list for reasons of clinical deterioration. Sex-specific potential cutoff values to define sarcopenia were determined with a grid search guided by log-rank test statistics. Optimal search methods identified potential cutoffs to detect survival differences between groups. The overall median SMI was 47.6 cm² /m² : 50.0 in men and 42.0 in women. At a median of 8.8 months follow-up, mortality was 25% in men and 36% in women. Patients who died had lower SMI than those who survived (45.6 versus 48.5 cm² /m² ; P < 0.001), and SMI was associated with wait-list mortality (hazard ratio, 0.95; P < 0.001). Optimal search method yielded SMI cutoffs of 50 cm² /m² for men and 39 cm² /m² for women; these cutoff values best combined statistical significance with a sufficient number of events to detect survival differences between groups. In conclusion, we recommend that an SMI < 50 cm² /m² for men and < 39 cm² /m² for women be used to define sarcopenia in patients with ESLD awaiting LT. Liver Transplantation 23 625-633 2017 AASLD.

Systematic Review and Meta-Analysis of the Impact of Computed Tomography-Assessed Skeletal Muscle Mass on Outcome in Patients Awaiting or Undergoing Liver Transplantation

Liver transplant outcome has improved considerably as a direct result of optimized surgical and anesthesiological techniques and organ allocation programs. Because there remains a shortage of human organs, strict selection of transplant candidates remains of paramount importance. Recently, computed tomography (CT)-assessed low skeletal muscle mass (i.e. sarcopenia) was identified as a novel prognostic parameter to predict outcome in liver transplant candidates. A systematic review and meta-analysis on the impact of CT-assessed skeletal muscle mass on outcome in liver transplant candidates were performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. Nineteen studies, including 3803 patients in partly overlapping cohorts, fulfilled the inclusion criteria. The prevalence of sarcopenia ranged from 22.2% to 70%. An independent association between low muscle mass and posttransplantation and waiting list mortality was described in 4 of the 6 and 6 of the 11 studies, respectively. The pooled hazard ratios of sarcopenia were 1.84 (95% confidence interval 1.11-3.05, p = 0.02) and 1.72 (95% confidence interval 0.99-3.00, p = 0.05) for posttransplantation and waiting list mortality, respectively, independent of Model for End-stage Liver Disease score. Less-consistent evidence suggested a higher complication rate, particularly infections, in sarcopenic patients. In conclusion, sarcopenia is an independent predictor for outcome in liver transplantation patients and could be used for risk assessment.