Energy expenditure and balance among long term liver recipients

From Listing to Recovery: A Review of Nutritional Status Assessment and Management in Liver Transplant Patients

Liver transplantation (LT) is a complex surgical procedure requiring thorough pre- and post-operative planning and care. The nutritional status of the patient before, during, and after LT is crucial to surgical success and long-term prognosis. This review aims to assess nutritional status assessment and management before, during, and after LT, with a focus on patients who have undergone bariatric surgery. We performed a comprehensive topic search on MEDLINE, Ovid, In-Process, Cochrane Library, EMBASE, and PubMed up to March 2023. It identifies key factors influencing the nutritional status of liver transplant patients, such as pre-existing malnutrition, the type and severity of liver disease, comorbidities, and immunosuppressive medications. The review highlights the importance of pre-operative nutritional assessment and intervention, close nutritional status monitoring, individualised nutrition care plans, and ongoing nutritional support and monitoring after LT. The review concludes by examining the effect of bariatric surgery on the nutritional status of liver transplant recipients. The review offers valuable insights into the challenges and opportunities for optimising nutritional status before, during, and after LT.

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.

Nutrition, dietary intake, and eating behavior after liver transplantation

PURPOSE OF REVIEW

Nutritional status of patients after liver transplantation is affected by dietary intake and this, in turn, is affected by eating behavior. The present review will highlight recent studies on these topics after liver transplantation.

RECENT FINDINGS

Malnutrition drops significantly after liver transplantation. Recovery of weight lost during liver disease occurs within 1 year. Liver transplantation recipients gain weight up to the second or third year, often becoming overweight and obese. Muscle mass may not recover completely, and sarcopenia could increase within 1 year after liver transplantation. Some studies, but not all, demonstrated modifications of food intake before and after liver transplantation. A positive energy balance was found in the first year, and a greater energy intake along time after liver transplantation, although some authors mentioned potential underreporting of the true consumption, mainly among people overweight/obese. Dietary survey methods are unable to detect eating behavior, resulting in a lack of data. Weight gain and obesity were related to higher scores for patterns of eating behaviors after liver transplantation. Food deprivation in the pretransplantation period and psychological factors could affect eating behavior and consequently food intake and nutritional status of liver transplantation patients.

SUMMARY

Understanding eating behavior after liver transplantation could be key knowledge regarding dietary intake and its impact on nutritional modifications occurring after liver transplantation.

Changes in dietary patterns and body composition within 12 months of liver transplantation

Background

Cardiometabolic risk factors are increasing in liver transplant recipients (LTR). Influencing dietary factors have not been assessed. The aim of this observational study was to assess changes in weight, metabolic function, dietary intake and eating behaviours in the first year after orthotopic liver transplantation (OLT).

Methods

Consecutive recruitment of 17 patients (14 males) awaiting OLT at a single tertiary hospital. Dietary intake, food behaviours and anthropometry were recorded at baseline, and 6 and 12 months post-transplant.

Results

By 12 months, patients had gained on average 7.3% of body weight. The prevalence of overweight or obesity increased from baseline 53% to 77% (P=0.001). By 6 months, 65% (n=11/17) of patients had altered glucose metabolism. Dietary intake was consistent with a Western-style dietary pattern with high saturated fat. Over half of the patients (69%, n=11/16) reported low to no depressive feelings and rated their self-esteem as good (53%, n=9/16). The Power of Food Scale increased between pre and post-transplant, indicating a stronger appetitive drive.

Conclusions

Weight gain occurs early post-transplant, with significant metabolic dysfunction present within 6 months, however is not associated with significant psychological distress. Early dietary intervention designed to limit weight gain and target cardiometabolic health is recommended for this unique patient population.

Resting and Exercise Energy Metabolism After Liver Transplantation for Nonalcoholic Steatohepatitis

Background

Nonalcoholic steatohepatitis (NASH) is a leading indication for liver transplantation (LT). We hypothesized that weight gain after LT may be exacerbated by reduced metabolic rates due to the LT procedure, particularly during exercise. We aimed to compare resting and exercise energy expenditure between patients transplanted for NASH and nontransplant nonalcoholic fatty liver disease (NAFLD) subjects.

Methods

NASH LT recipients (>1-year post, n = 14) and NAFLD controls (n = 13) underwent analysis of body composition, resting energy expenditure (REE), and exercise energy expenditure (VO_2max), the latter using a ramped-Bruce protocol assessed by expired gas analysis and peak heart rate.

Results

Participants were mean 61.5 ± 7.9 years, 48.1% men, and 66.7% white. Baseline comorbidities were similar between groups. Among men, mean REE adjusted for total (17.7 vs 18.8, P = 0.87) and lean body mass (23.5 vs 26.9, P = 0.26), as well as VO₂ (20.1 vs 23.9, P = 0.29), was lower in NASH LT recipients compared with NAFLD controls, respectively, although not statistically significant. However, female NASH LT recipients had significantly lower mean REE than NAFLD controls when adjusted for total (14.2 vs 18.9, P = 0.01) and lean body mass (19.3 vs 26.5, P = 0.002), as well as significantly lower VO_2max (14.4 vs 20.6, P = 0.017).

Conclusions

NASH LT recipients, particularly women, have lower REE and exercise energy expenditure compared with nontransplant NAFLD patients. More aggressive diet and exercise programs for post-LT NASH recipients to account for reduced resting and exercise metabolic rates may attenuate weight gain in this vulnerable population.

Nutrition in liver transplantation: too little or too much?

PURPOSE OF REVIEW

The purpose of this study was to review the most recent findings on approaches to managing the obesity and muscle wasting that are found in patients before and after liver transplantation.

RECENT FINDINGS

A number of articles have contributed to the accumulating evidence that morbid obesity is not an absolute contraindication to liver transplantation with survival outcomes similar across BMI groups. Obesity is, however, a risk factor for early post-transplant complications and obesity-related comorbidities markedly increase this risk. Very limited data are as yet available, dietary, or otherwise, related to amelioration of these comorbidities and evidence that weight loss leads to improved outcomes in obese patients is lacking. Abdominal computed tomography imaging is increasingly being used to identify muscle wasting, and poorer post-transplant survival is seen in patients with significant muscle wasting. This modality has confirmed the persistence of depleted muscle stores after transplant extending well beyond 1 year. Coupled with this is a high incidence of weight gain and metabolic syndrome and the associated risks. Although dietary intervention and exercise are considered possible approaches to address these issues, work in these areas so far is sparse.

SUMMARY

An urgent need exists for interventional studies on the basis of nutrition and/or exercise to address the challenges presented by both obesity and muscle wasting, which likely coexist in many patients in both the pretransplant and the post-transplant periods.