Prevalence and factors associated with dyslipidemia after liver transplantation

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.

Exercise interventions for adults after liver transplantation

BACKGROUND

The finding that exercise is inversely related to metabolic syndrome after transplantation is novel and suggests that exercise interventions might provide a means for reducing metabolic syndrome complications in liver transplantation recipients. The use of exercise for increasing the physical activity daily levels by more frequent, higher intensity, and longer duration of training sessions, or the sum of these components may be necessary to counteract the effects of the pretransplant reduced activity, metabolic disturbances, and post-transplant immunosuppression, as well as improve physical function and aerobic capacity following liver transplantation. Regular physical activity has a long-term positive impact on recovery following various surgical procedures including transplantation, giving people the opportunity to return to an active life with their families, in society, and in their professional life. Likewise, specific muscle strength training may attenuate the loss of strength after liver transplantation.

OBJECTIVES

To evaluate the benefits and harms of exercise-based interventions in adults after liver transplantation compared to no exercise, sham interventions, or another type of exercise.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search date was 2 September 2022.

SELECTION CRITERIA

We included randomised clinical trials in liver transplantation recipients comparing any type of exercise with no exercise, sham interventions, or another type of exercise.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcomes were 1. all-cause mortality; 2. serious adverse events; and 3. health-related quality of life. Our secondary outcomes were 4. a composite of cardiovascular mortality and cardiac disease; 5. aerobic capacity; 6. muscle strength; 7. morbidity; 8. non-serious adverse events; and 9. cardiovascular disease post-transplantation. We assessed risk of bias of the individual trials using RoB 1, described the interventions using the TIDieR checklist, and used GRADE to assess certainty of evidence.

MAIN RESULTS

We included three randomised clinical trials. The trials randomised 241 adults with liver transplantation, of which 199 participants completed the trials. The trials were conducted in the USA, Spain, and Turkey. They compared exercise versus usual care. The duration of the interventions ranged from two to 10 months. One trial reported that 69% of participants who received the exercise intervention were adherent to the exercise prescription. A second trial reported a 94% adherence to the exercise programme, with participants attending 45/48 sessions. The remaining trial reported a 96.8% adherence to the exercise intervention during the hospitalisation period. Two trials received funding; one from the National Center for Research Resources (US) and the other from Instituto de Salud Carlos III (Spain). The remaining trial did not receive funding. All trials were at an overall high risk of bias, derived from high risk of selective reporting bias and attrition bias in two trials. The results on all-cause mortality showed a higher risk of death in the exercise group versus the control group, but these results are very uncertain (risk ratio (RR) 3.14, 95% confidence interval (CI) 0.74 to 13.37; 2 trials, 165 participants; I² = 0%; very low-certainty evidence). The trials did not report data on serious adverse events excluding mortality or non-serious adverse events. However, all trials reported that there were no adverse effects associated with exercise. We are very uncertain on whether exercise compared with usual care has a beneficial or harmful effect on health-related quality of life assessed using the 36-item Short Form Physical Functioning subscale at the end of the intervention (mean difference (MD) 10.56, 95% CI -0.12 to 21.24; 2 trials, 169 participants; I² = 71%; very low-certainty evidence). None of the trials reported data on composite of cardiovascular mortality and cardiovascular disease, and cardiovascular disease post-transplantation. We are very uncertain if there are differences in aerobic capacity in terms of VO2peak at the end of the intervention between groups (MD 0.80, 95% CI -0.80 to 2.39; 3 trials, 199 participants; I² = 0%; very low-certainty evidence). We are very uncertain if there are differences in muscle strength at end of the intervention between groups (MD 9.91, 95% CI -3.68 to 23.50; 3 trials, 199 participants; I² = 44%; very low-certainty evidence). One trial measured perceived fatigue using the Checklist Individual Strength (CIST). Participants in the exercise group showed a clinically important lower degree of fatigue perception than participants in the control group, with a mean reduction of 40 points in the CIST (95% CI 15.62 to 64.38; 1 trial, 30 participants).  We identified three ongoing studies.

AUTHORS' CONCLUSIONS

Based on very low-certainty evidence in our systematic review, we are very uncertain of the role of exercise training (aerobic, resistance-based exercises, or both) in affecting mortality, health-related quality of life, and physical function (i.e. aerobic capacity and muscle strength) in liver transplant recipients. There were few data on the composite of cardiovascular mortality and cardiovascular disease, cardiovascular disease post-transplantation, and adverse event outcomes. We lack larger trials with blinded outcome assessment, designed according to the SPIRIT statement and reported according to the CONSORT statement.

Prognostic implication of early posttransplant hypercholesterolemia in liver transplantation for patients with hepatocellular carcinoma

BACKGROUND

Hyperlipidemia is a common complication after liver transplantation (LT) and develops mostly in the early posttransplant period. Recently, some studies have reported a positive correlation between hyperlipidemia and favorable prognosis in patients with hepatocellular carcinoma (HCC) undergoing hepatectomy. This study aimed to evaluate the possibility of predicting prognosis in HCC patients receiving LT by early posttransplant dyslipidemia.

METHODS

From January 2015 to December 2017, a total of 806 HCC patients from China Liver Transplant Registry database were retrospectively enrolled. The prognostic relevance of early posttransplant hypertriglyceridemia or hypercholesterolemia was examined using survival analysis, and subgroup analysis was implemented based on LT criteria.

RESULTS

Early posttransplant hypercholesterolemia (EPHC) was independently inversely associated with the risk of recurrence [hazard ratio (HR) = 0.630; P = 0.022], but was not significantly correlated with the mortality. However, early posttransplant hypertriglyceridemia was not related to prognosis. Intriguingly, with further classification, we found that borderline EPHC (B-EPHC), instead of significant EPHC, was a predictor of lower risk for both recurrence (HR = 0.504; P = 0.006) and mortality (HR = 0.511; P = 0.023). Compared with non-EPHC patients, B-EPHC patients achieved significantly superior 1-year and 3-year tumor-free survival (89.6% and 83.7% vs. 83.8% and 72.7% respectively; P = 0.023), and 1-year and 3-year overall survival (95.8% and 84.8% vs. 94.6% and 77.6% respectively; P = 0.039). In the subgroup analysis, B-EPHC remained an independent predictor of better prognosis in patients beyond Milan criteria and those within Hangzhou criteria; whereas there was no significant relationship between B-EPHC and prognosis in patients within Milan criteria and those beyond Hangzhou criteria. More interestingly, patients beyond Milan criteria but within Hangzhou criteria were identified as the crucial subpopulation who benefited from B-EPHC (recurrence HR = 0.306, P = 0.011; mortality HR = 0.325, P = 0.031).

CONCLUSIONS

B-EPHC could assist transplant teams in dynamically evaluating prognosis after LT for HCC as a postoperative non-oncological biomarker, especially in patients beyond Milan criteria but within Hangzhou criteria.

DO THE IMMUNOSUPPRESSIVE DRUGS AFFECT THE HYPOTHALAMIC NUCLEI INVOLVED IN THE REGULATION OF FOOD INTAKE? AN EXPERIMENTAL STUDY

PURPOSE

Immunosuppressive drugs are essential for reducing the rejection risk in post-transplant patients, which is commonly associated with this procedure. However, side effects of those drugs on the hypothalamic nuclei involved in the food intake regulation, excessive weight gain, and also associated comorbidities are still unknown. The purpose of this study was to analyze possible changes in the neuronal morphology and cell density in the paraventricular nuclei, lateral hypothalamic area, dorsomedial nuclei, and ventromedial and arcuate nuclei in Wistar rats submitted to immunosuppressive treatment with tacrolimus (TAC) or mycophenolate mofetil (MMF).

METHODS

Adult male Wistar rats were randomly assigned to the following groups according to the oral treatment administered for 14 weeks: control, sham (placebo), TAC (1 mg/kg of weight), and MMF (30 mg/kg of weight). After treatment, the animals were sacrificed and their brains fixed for later histological staining. Subsequently, the slides were photodocumented for stereological analysis of the hypothalamic nuclei.

RESULTS

All experimental groups showed a weight gain throughout the study. There was no significant difference in neuronal density/number of cells in the hypothalamic nuclei between groups. Morphological changes were not detected in the hypothalamic neurons.

CONCLUSION

Treatments with immunosuppressants could not modify the morphological and cell density aspects of the hypothalamic nuclei during this supplementation period.

Lipid profiles of donors and recipients of liver transplant: like father like son

BACKGROUND/PURPOSE

Dyslipidemia is common in liver transplant recipients. This retrospective study investigates whether donors play a role.

METHODS

Prospectively collected data of donors and recipients of deceased-donor liver transplantation (DDLT) and living-donor liver transplantation (LDLT) were reviewed. Total cholesterol, triglyceride, low-density lipoprotein, high-density lipoprotein (HDL) and fasting glucose were compared between groups. HDL ≥1.6 mmol/L at 2 years after transplant was considered the marker of a favorable post-transplant lipid profile in recipients. Univariate and multivariate analyses were performed to identify predictive factors for this marker.

RESULTS

There were 85 DDLTs and 80 LDLTs. LDLT donors were younger (30 vs. 50 years, p < 0.001) and lighter (58.2 vs. 63.4 kg, p = 0.008) and had a lower body mass index (21.2 vs. 23.7, p < 0.001). The DDLT group had more fatty grafts (p = 0.001) and longer cold (375 vs. 103.5 min, p < 0.001) and warm (50.5 vs. 46 min, p = 0.034) ischemia. LDLT donors had lower fasting glucose (4.85 vs. 7.21 mmol/L, p < 0.001) and triglyceride (0.87 vs. 1.22 mmol/L, p = 0.016) but higher HDL (1.58 vs. 1.39 mmol/L, p = 0.022). LDLT recipients also had higher HDL at 1 year (1.48 vs. 1.28 mmol/L, p = 0.026) and 2 years (1.43 vs. 1.21 mmol/L, p = 0.008). Fourteen (16.5%) DDLT recipients and 27 (33.8%) LDLT recipients had HDL ≥1.6 mmol/L at 2 years. On multivariate analysis, donor HDL ≥1.6 mmol/L (RR 4.311, 95% CI 1.666-11.158, p = 0.003) and recipient body mass index <24 (RR 2.753, 95% CI 1.064-7.127, p = 0.037) were the two independent predictive factors.

CONCLUSION

LDLT recipients had better lipid profiles than DDLT recipients. The feature of high HDL level in donors was transferred to recipients.

DIETARY MANAGEMENT FOR DYSLIPIDEMIA IN LIVER TRANSPLANT RECIPIENTS

Background

Dyslipidemia occurs in approximately 70% of all liver transplant (LT) recipients, and no prior control studies have demonstrated any dietary intervention to change it.

Aim

To analyze the effects of a dietary intervention on the lipid profile of dyslipidemic LT recipients.

Methods

All LT recipients with dyslipidemia on clinical follow-up were enrolled. Anthropometric evaluation, food history, body composition (bioimpedance) and assessment of basal metabolism through indirect calorimetry were performed. Patients met with a dietitian and an individualized diet based on estimate of basal metabolism and consisting of 25% of the total energy value in total fat and <200 mg/day of cholesterol was prescribed. Total cholesterol (TC), HDL-cholesterol (HDL), LDL-cholesterol (LDL), triglycerides (TG) and anthropometric measures were measured at baseline and six months after intervention.

Results

Fifty-thee out of 56 patients concluded follow-up; age was 59±10 years; 29 were men (51.8%). The analysis pre- and post-intervention were, respectively: TC 238.9±30 and 165.1±35, p<0.001; LDL 154±33 and 90±29, p<0.001; and TG 168 (IQR=51-200) and 137 (IQR=94-177), p=<0.001. They were all modified at six months following intervention. At baseline, none of the patients had normal TC, and only 12 (22.7%) had optimal/near optimal LDL. Following dietary intervention, 45 patients (84.9%) reached normal TC and 50 (94.4%) had optimal/near optimal LDL. HDL and anthropometric measures were not modified.

Conclusions

Dietary counseling with prescription of individualized diet based on estimate of basal metabolism through indirect calorimetry was able to manage dyslipidemia in most LT recipients; so, all dyslipidemic LT recipients must be enrolled on a dietary program.