Nutrition in liver transplantation: too little or too much?

Nutritional Management of a Liver Transplant Candidate

Nearly two-thirds of patients with cirrhosis suffer from malnutrition resulting from multiple contributory factors such as poor intake, accelerated starvation, catabolic milieu, and anabolic resistance. Nutritional assessment and optimization are integral to adequate management of a liver transplant (LT) candidate. A detailed nutritional assessment should be done at baseline in all potential transplant candidates with periodic reassessments. Sarcopenia is defined as a reduction in muscle mass, function, and/or performance. Skeletal muscle index at 3rd lumbar vertebra determined by computed tomography is the most objective tool to assess muscle mass. Hand-grip strength and gait speed are simple tools to gauge muscle strength and performance, respectively. Sarcopenia, sarcopenic obesity, and myosteatosis portend poor outcomes. Sarcopenia contributes greatly to frailty, which is a syndrome of reduced physiological reserve and impaired response to stressors. Dietary interventions must ensure adequate calorie (35-40 kcal/kg/day) and protein (1.2-1.5 gm/kg/day) intake via multiple frequent meals and late-evening calorie-dense snack. Micronutrient supplementation is essential, keeping in mind the etiology of cirrhosis. Individualized, gradually up-titrated exercise prescription consisting of both aerobic and resistance training of 150 min/week is advisable after appropriate risk assessment. Early initiation of enteral nutrition within 12-24 h of LT is recommended. Data with respect to immune-nutrition, monomeric formulas, and hormone replacement remain conflicting at present. A multidisciplinary team comprising of hepatologists, transplant surgeons, intensivists, dieticians, and physiotherapists is vital to improve overall nutrition and outcomes in this vulnerable group.

Nutritional Intake after Liver Transplant: Systematic Review and Meta-Analysis

Cardiovascular disease and its concurrent risk factors are prevalent after liver transplant (LT). Most of these risk factors are modifiable by diet. We aimed to synthesise the literature reporting the nutritional intake of liver transplant recipients (LTR) and the potential determinants of intake. We performed a systematic review and meta-analyses of studies published up until July 2021 reporting the nutritional intake of LTR. The pooled daily mean intakes were recorded as 1998 (95% CI 1889, 2108) kcal, 17 (17, 18)% energy from protein, 49 (48, 51)% energy from carbohydrates, 34 (33, 35)% energy from total fat, 10 (7, 13)% energy from saturated fat, and 20 (18, 21) g of fibre. The average fruit and vegetable intake ranged from 105 to 418 g/day. The length of time post-LT and the age and sex of the cohorts, as well as the continent and year of publication of each study, were sources of heterogeneity. Nine studies investigated the potential determinants of intake, time post-LT, gender and immunosuppression medication, with inconclusive results. Energy and protein requirements were not met in the first month post-transplant. After this point, energy intake was significantly higher and remained stable over time, with a high fat intake and low intake of fibre, fruits and vegetables. This suggests that LTR consume a high-energy, low-quality diet in the long term and do not adhere to the dietary guidelines for cardiovascular disease prevention.

Bioelectrical impedance vector analysis in patients on the waiting list for liver transplant: Associated factors and prognostic effects

OBJECTIVES

The aim of this study was to assess patients on the waiting list for liver transplant (LTx) according to bioelectrical impedance vector analysis (BIVA), as well as to verify the association between the placement of the vectors on the graph with clinical outcomes and identify the predictors to vector placement in quadrant 4 (Q4; indicating more hydration and less cellularity).

METHODS

This was a retrospective observational study including 129 patients ≥20 y of age awaiting LTx. Patients' nutritional status was assessed by using different tools, including single-frequency bioelectrical impedance analysis and the Subjective Global Assessment (SGA). Clinical data were registered. The BIVA was evaluated by comparing the individual vectors plotted for all patients to the tolerance ellipses of 50%, 75%, and 95% of the reference healthy population. The quadrant of the vector for each patient was registered.

RESULTS

The majority of the vectors were placed in Q1 (n = 54; 41.9%) and Q4 (n = 39; 30.2%). The presence of ascites or edema (hazard ratio [HR], 2.43; 95% confidence interval [CI], 1.15-5.12; P = 0.019) and the BIVA vector placed in Q4 in any ellipse (HR, 2.10; 95% CI, 1.07-4.09; P = 0.029) were independent predictors for mortality on the waiting list or ≤1 y after LTx. BIVA was not associated with longer hospital length of stay. The predictors of vector placement in Q4 were higher age, malnutrition according to SGA, and presence of ascites or edema.

CONCLUSION

Patients on the waiting list for LTx with BIVA vectors placed in Q4, in the 50%, 75%, or 95% tolerance ellipses, presented a worse prognosis.

[Nutritional Status of Liver Transplantation Recipients and Factors Influencing Nutritional Status]

PURPOSE

This study aimed to investigate the nutritional status of liver transplantation (LT) recipients and explore certain factors that influence nutritional status, including dietary patterns and physical activities.

METHODS

This was a cross-sectional, descriptive study. The subjects included 211 LT recipients at a medical center outpatient clinic located in Seoul, Korea. The nutritional status, dietary patterns, and physical activities of each subject were measured using the body mass index (BMI), Mini Dietary Assessment (MDA), and Global Physical Activity Questionnaire. Independent t-test, one-way analysis of variance, and multiple linear regression analysis were used to analyze the data.

RESULTS

The percentages of living and deceased donor LTs were 81.0% and 19.0%, respectively. The mean BMIs pre- and post-LT were 23.88 and 23.16 kg/m², respectively, and the average MDA score was 36.55. More than 60.0% of the subjects had a moderate or high level of physical activity. In multivariate analysis, a higher BMI before LT (β=.72, p<.001), a lower Model for End-stage Liver Disease (MELD) score (β=-.18, p<.001), and being male (β=-.10, p=.024) contributed to better nutritional status post-LT. Patients within six months of LT were less engaged in muscle exercises than those post six months of LT (p=.020).

CONCLUSION

LT recipients in Korea have good nutritional status and a good level of physical activity. To improve recipients' post-LT nutritional status, the pre-LT nutritional status should be considered, particularly in those with a higher MELD score. In addition, physical activity including muscle-strengthening exercises should be encouraged from an earlier stage.

Obesity, dynapenia and high cardiovascular risk co-exist in post-liver transplant setting: results of a cross-sectional study

BACKGROUND

Cardiovascular disease is a major cause of death in post-liver transplantation (LT). The aim of this study was to evaluate LT patients as to the carotid intima-media thickness (CIMT) and its association with nutritional status, dietary intake, metabolic profile and cardiovascular risk factors.

METHODS

In this cross-sectional study, adult patients with more than 12 months of post-transplant follow-up underwent clinical, laboratory, functional and nutritional evaluation by 3-day-diet-record, anthropometry and dynamometry. CIMT was evaluated by Doppler ultrasonography.

RESULTS

Sixty-nine post-LT patients [males 61%, median of age 59 (51-64) years were included; median time post-liver transplantation 2.8 (1.4-6.3) years]. High prevalence of malnutrition was found (45% of arm muscle area < p15 and 71% of handgrip strength < p30). Excess weight was present in 72% of patients, body mass index ≥ 30 kg/m² in 35% and metabolic syndrome in 51%. Abnormal CIMT was found in 54% of the sample. Patients with abnormal CIMT presented higher cardiovascular risk Score, LDL cholesterol, higher prevalence of high-sensitive C-reactive protein ≥ 1 mg/L and higher intake of saturated and trans fatty acids (P < 0.05 for all).

CONCLUSIONS

Abnormal IMT was commonly found in LT patients presenting at the same time with overweight and dynapemia. These results were associated with higher LDL-cholesterol levels, high-sensitive C-reactive protein ≥ 1 mg/L and higher intake of saturated and trans fatty acids. Preventive measures, including dietary advice, are required for all post-liver transplantation patients to minimize cardiovascular risk.

Management of diabetes mellitus in patients undergoing liver transplantation

Diabetes is a common feature in cirrhotic individuals both before and after liver transplantation and negatively affects prognosis. Certain aetiological agents of chronic liver disease and loss of liver function per se favour the occurrence of pre-transplant diabetes in susceptible individuals, whereas immunosuppressant treatment, changes in lifestyle habits, and donor- and procedure-related factors contribute to diabetes development/persistence after transplantation. Challenges in the management of pre-transplant diabetes include the profound nutritional alterations characterizing cirrhotic individuals and the limitations to the use of drugs with liver metabolism. Special issues in the management of post-transplant diabetes include the diabetogenic potential of immunosuppressant drugs and the increased cardiovascular risk characterizing solid organ transplant survivors. Overall, the pharmacological management of cirrhotic patients undergoing liver transplantation is complicated by the lack of specific guidelines reflecting the paucity of data on the impact of glycaemic control and the safety and efficacy of anti-hyperglycaemic agents in these individuals.

Relationship Between Total Body Protein and Cross-Sectional Skeletal Muscle Area in Liver Cirrhosis Is Influenced by Overhydration

Sarcopenia as defined by reduced skeletal muscle area (SMA) on cross-sectional abdominal imaging has been proposed as an objective measure of malnutrition, and it is associated with both wait-list mortality and posttransplant complications in patients with cirrhosis. SMA, however, has never been validated against the gold standard measurement of total body protein (TBP) by in vivo neutron activation analysis (IVNAA). Furthermore, overhydration is common in cirrhosis, and its effect on muscle area measurement remains unknown. We aimed to examine the relationship between SMA and TBP in patients with cirrhosis and to assess the impact of overhydration on this relationship. Patients with cirrhosis who had undergone IVNAA and cross-sectional imaging within 30 days were retrospectively identified. Patients with significant clinical events between measurements were excluded. Psoas muscle area (PMA) and SMA at the level of the third lumbar vertebrae were determined. Total body water was estimated from a multicompartment model and expressed as a fraction of fat-free mass (FFM), as determined by dual-energy X-ray absorptiometry, to provide an index of hydration status. In total, 107 patients underwent 109 cross-sectional imaging studies (87 computed tomography; 22 magnetic resonance imaging) within 30 days of IVNAA. Median time between measurements was 1 day (IQR, -1 to 3 days). Between 43% and 69% of the cohort was identified as sarcopenic, depending on muscle area cutoff values used. TBP was strongly correlated with SMA (r = 0.78; P < 0.001) and weakly correlated with PMA (r = 0.49; P < 0.001). Multiple linear regression showed SMA was significantly and positively associated with FFM hydration (P < 0.001) independently of TBP. In conclusion, SMA is more closely related to TBP than is PMA, and it should be preferred as a measure of sarcopenia. Overhydration significantly affects the measurement of cross-sectional muscle area.