Nutrition Trends in Patients Over the Long Term After Kidney Transplantation

Immunosuppressive therapy and nutritional diseases of patients after kidney transplantation: a systematic review

BACKGROUND

Kidney transplantation (kTx) is by far the most effective method of treating end-stage renal disease, with immunosuppressive therapy being obligatory for all, except identical twins. Despite kTx being the most effective treatment for end-stage renal disease, the patients face significant morbidity. They are often burdened with diabetes, anaemia, lipid disorders, all of which pose heightened risks for cardiovascular disease. Knowing that nutritional status plays a significant role in post-transplant results including graft survival, we conducted this systematic review with the aim to summarise the evidence of nutritional diseases following exposure to immunosuppressive therapy among patients after kTx.

METHODS

This systematic review is reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 checklist. Our search encompasses observational studies (cohort, case-control, cross-sectional) and randomized controlled trials (RCTs), published and unpublished, completed, and ongoing, written in English from the last 10 years (up to 17th February 2023) in the following databases: MEDLINE (via PubMed), EMBASE (Elsevier), Scopus and Web of Science. Any settings were eligible for inclusion. Quality assessments were done using ROBINS-I and RoB2 tools. Results were summarised in a narrative synthesis. Quantitative analysis was conducted where feasible. The protocol for proposed systematic review was published elsewhere.

RESULTS

A total of 24 studies were included (participants n = 9,536) in the review. The majority of studies were cohort (n = 16), with moderate or low quality. Most of the studies (n = 16) were conducted in hospital settings. All studies had a higher proportion of male participants compared to female participants, except for one. Diabetes emerged as the most frequent disease assessed (n = 14), while tacrolimus (Tac) was the most commonly evaluated immunosuppressive medication used (n = 16). As a result, Tac presented a higher risk factor for the development of diabetes compared to cyclosporine (CsA). In addition, Tac was linked to weight gain in post-transplant recipients. In contrary, no relationship was found between steroids and weight gain. Regarding other immunosuppressants, everolimus was found to be associated with lipid abnormalities. Though, the relationship between lipid abnormalities and steroid use yielded inconsistent results. Calcineurin inhibitors (CNIs) were studied in various research articles. Consequently, patients who were not using CNIs had a lower prevalence of hypomagnesaemia, hyperkalaemia, and metabolic acidosis compared to those treated with CNIs. Also, CNIs were found to have a negative impact on 25-hydroxyvitamin D (25(OH)D) levels. Another aspect was the use of slow and fast Tacrolimus metabolizers. There was no difference observed in phase angle, visceral fat area, lean body mass index, and the proportion of lean mass as a percentage of total body mass between them. Finally, mammalian target of rapamycin (mTOR) inhibitors was associated with bone status and mycophenolate mofetil was linked to Vitamin B12 deficiencies.

CONCLUSIONS

To the best of our knowledge, this systematic review represents the first comprehensive overview of the evidence regarding immunosuppressive therapy and nutritional diseases in kTx patients. Our findings indicate an association between immunosuppressive therapy and nutritional diseases in this population. However, there is high heterogeneity and suboptimal quality of the included studies. Future researchers should prioritise high-quality, prospective randomized controlled trials to further elucidate these relationships.

TRIAL REGISTRATION

PROSPERO (CRD42023396773), dated 12 April 2023. Protocol publication: https://doi.org/10.3390/jcm12216955 .

Conscious Nutrition to Improve Survival Prognosis of Donor Kidney Recipients: A Narrative Review

Kidney transplantation is the optimal treatment for end-stage chronic kidney disease, increasing survival rates and improving quality of life. Diet affects patient weight and well-being, can trigger certain diseases, and influences post-surgery outcomes. The purpose of the study was to investigate dietary strategies in patients with chronic kidney disease, in early and long-term donor kidney recipients, and to formulate specific nutritional recommendations. For this purpose, a narrative review of the available information in both the Republic of Kazakhstan and the world's scientific literature over the last 10 years was carried out. The following evidence-based resources were used: Scopus, PubMed, Embase, Cochrane Library, and Web of Knowledge. The study provides the latest statistical data on kidney transplantation and risk factors, and a comparative analysis between countries. Existing data on basic nutrition and the possibility of using it after transplantation are examined in detail. In addition, the recommendations for daily intake of salt, potassium, sodium, vitamin D, and calcium were analyzed. The energy value of the diet and its association with overweight, obesity, and the development of diabetes mellitus were studied. Using DASH (Dietary Approaches to Stop Hypertension) and low-protein diets as examples, the potential risks and their applicability for this patient category are analyzed. The article's materials and conclusions can serve as a training manual for nephrologists, therapists, and surgeons.

Ultra-Processed Food Consumption, Poorer Nutritional Quality, and Lower Muscle Mass in Immediate and Late Postkidney Transplant Periods

OBJECTIVE

To assess the consumption of ultra-processed foods (UPFs) in the immediate (2 months after transplantation) and late post-transplant (14 months after transplantation) periods among kidney transplant patients and to examine its correlation with nutritional quality and body composition.

DESIGN AND METHODS

A cross-sectional analysis of 96 kidney transplant recipients divided into 2 groups: immediate post-transplant (n = 71) and late post-transplant (n = 25). Sociodemographic, anthropometric, and laboratory data were collected and grouped in a database. Food intake was evaluated by a validated food frequency questionnaire and foods were divided according to the NOVA classification system. The consumption of UPFs was calculated and statistical analyses were performed to evaluate its correlation with nutritional components and body composition.

RESULTS

The consumption of UPFs was 649.4 [420.0-1061.72] kcal/day, accounting for 33.3 ± 11.9% of the total daily energy intake. The immediate post-transplant group showed higher total daily energy and UPFs intake compared to the late post-transplant group (P = .002 and P = .046, respectively), although the energy contribution of UPFs was similar between both groups. UPFs intake was positively correlated with higher percentages of total fat, trans fat, saturated, monounsaturated fat, polyunsaturated fat, starch, and sodium (P < .05 for all analyses). An inverse correlation was observed between UPFs consumption and the percentage of protein and carbohydrates in the food intake (P = .025 and P = .008, respectively). In the immediate post-transplant group, a higher intake of UPFs was correlated with lower muscle mass (r = -0.250, P = .037).

CONCLUSIONS

The findings of this study reveal a pattern of increased consumption of UPFs among kidney transplant patients in comparison to the national average. This higher intake of UPFs was correlated with lower nutritional quality during both periods. Moreover, a significant correlation was observed between UPFs consumption and adverse body composition parameters, specifically in the immediate post-transplant period.

The Impact and Effectiveness of Weight Loss on Kidney Transplant Outcomes: A Narrative Review

Obesity is a worldwide epidemic that leads to several non-communicable illnesses, including chronic kidney disease (CKD). Diet and lifestyle modifications have shown a limited impact in the treatment of obesity. Because the group of end-stage renal disease (ESRD) patients examined in this study had limited access to kidney transplantation (KT), patients with obesity were thought to be at an increased risk of intraoperative and postoperative KT complications. Although bariatric surgery (BS) is now recognized as the gold standard treatment for morbid obesity, its role in ESRD or kidney transplant patients remains unknown. It is critical to know the correlation between weight loss and complications before and after KT, the impact of the overall graft, and patients' survival. Hence, this narrative review aims to present updated reports addressing when to perform surgery (before or after a KT), which surgical procedure to perform, and again, if strategies to avoid weight regain must be specific for these patients. It also analyzes the metabolic alterations produced by BS and studies its cost-effectiveness pre- and post-transplantation. Due to the better outcomes found in KT recipients, the authors consider it more convenient to perform BS before KT. However, more multicenter trials are required to provide a solid foundation for these recommendations in ERSD patients with obesity.

Nutrition Disturbances and Metabolic Complications in Kidney Transplant Recipients: Etiology, Methods of Assessment and Prevention-A Review

Nutrition disturbances occur at all stages of chronic kidney disease and progress with the decrease of the kidney filtration rate. Kidney transplantation (KTx) as the best form of kidney replacement therapy poses various nutritional challenges. Prior to transplantation, recipients often present with mild to advanced nutrition disturbances. A functioning allograft not only relieves uremia, acidosis, and electrolyte disturbances, but also resumes other kidney functions such as erythropoietin production and vitamin D3 metabolism. KTx recipients represent a whole spectrum of undernutrition and obesity. Since following transplantation, patients are relieved of most dietary restrictions and appetite disturbances; they resume old nutrition habits that result in weight gain. The immunosuppressive regimen often predisposes them to dyslipidemia, glucose intolerance, and hypertension. Moreover, most recipients present with chronic kidney graft disease at long-term follow-ups, usually in stages G2-G3T. Therefore, the nutritional status of KTx patients requires careful monitoring. Appropriate dietary and lifestyle habits prevent nutrition disturbances and may improve kidney graft function. Despite many nutritional guidelines and recommendations targeted at chronic kidney disease, there are few targeted at KTx recipients. We aimed to provide a brief review of nutrition disturbances and known nutritional recommendations for kidney transplant recipients based on the current literature and dietary trends.

Dyslipidemia in Renal Transplant Recipients

Dyslipidemia is a frequent complication after kidney transplantation (KT) and is an important risk factor for cardiovascular disease (CVD). Renal transplant recipients (RTRs) are considered at high, or very high, risk of CVD, which is a leading cause of death in this patient group. Despite many factors of post-transplant dyslipidemia, the immunosuppressive treatment has the biggest influence on a lipid profile. There are no strict dyslipidemia treatment guidelines for RTRs, but the ones proposing an individual approach regarding CVD risk seem most suitable. Proper diet and physical activity are the main general measures to manage dyslipidemia and should be introduced initially in every patient after KT. In the case of an insufficient correction of lipemia, statins are the basis for hypolipidemic treatment. Statins should be introduced with caution to avoid serious side-effects (e.g., myopathy) or drug-drug interactions, especially with immunosuppressants. To lower the incidence of adverse effects, and improve medication adherence, ezetimibe in combination with statins is recommended. Fibrates and bile sequestrants are not recommended due to their side-effects and variable efficacy. However, several new lipid-lowering drugs like Proprotein convertase subtilisin/Kexin type9 (PCSK9) inhibitors may have promising effects in RTRs, but further research assessing efficacy and safety is yet to be carried out.

Medical nutritional therapy for renal transplantation in the COVID-19 pandemic

Nutritional therapy is very important at renal transplantation. Nutrition has become more vital for transplantation patients owing to the coronavirus disease 2019 (COVID-19) pandemic. Inadequate nutrition can negatively affect the immune system. For this reason, adequate protein and energy intake should be provided to the patients. Also, overconsumption of saturated fat, sugar, and refined carbohydrates can both negatively affect the immune system and trigger chronic diseases in transplantation patients. In addition, vitamins and minerals should be monitored and inadequacy should be prevented due to immunomodulatory effects. Applying nutritional therapy suitable for the symptoms of renal transplantation patients and preventing comorbidities may reduce the risk and severity of COVID-19 infection.