Obesity Risk Factors in Patients After Kidney Transplantation

Skeletal muscle atrophy in clinical and preclinical models of chronic kidney disease: A systematic review and meta-analysis

Patients with chronic kidney disease (CKD) are often regarded as experiencing wasting of muscle mass and declining muscle strength and function, collectively termed sarcopenia. The extent of skeletal muscle wasting in clinical and preclinical CKD populations is unclear. We evaluated skeletal muscle atrophy in preclinical and clinical models of CKD, with multiple sub-analyses for muscle mass assessment methods, CKD severity, sex and across the different preclinical models of CKD. We performed a systematic literature review of clinical and preclinical studies that measured muscle mass/size using the following databases: Ovid Medline, Embase and Scopus. A random effects meta-analysis was utilized to determine standard mean difference (SMD; Hedges' g) between healthy and CKD. Heterogeneity was evaluated using the I2 statistic. Preclinical study quality was assessed via the Systematic Review Centre for Laboratory Animal Experimentation and clinical studies quality was assessed via the Newcastle-Ottawa Scale. This study was registered in PROSPERO (CRD42020180737) prior to initiation of the search. A total of 111 studies were included in this analysis using the following subgroups: 106 studies in the primary CKD analysis, 18 studies that accounted for diabetes and 7 kidney transplant studies. Significant atrophy was demonstrated in 78% of the preclinical studies and 49% of the clinical studies. The random effects model demonstrated a medium overall SMD (SMD = 0.58, 95% CI = 0.52-0.64) when combining clinical and preclinical studies, a medium SMD for the clinical population (SMD = 0.48, 95% CI = 0.42-0.55; all stages) and a large SMD for preclinical CKD (SMD = 0.95, 95% CI = 0.76-1.14). Further sub-analyses were performed based upon assessment methods, disease status and animal model. Muscle atrophy was reported in 49% of the clinical studies, paired with small mean differences. Preclinical studies reported significant atrophy in 78% of studies, with large mean differences. Across multiple clinical sub-analyses such as severity of CKD, dialysis modality and diabetes, a medium mean difference was found. Sub-analyses in both clinical and preclinical studies found a large mean difference for males and medium for females suggesting sex-specific implications. Muscle atrophy differences varied based upon assessment method for clinical and preclinical studies. Limitations in study design prevented conclusions to be made about the extent of muscle loss with disease progression, or the impact of dialysis. Future work would benefit from the use of standardized measurement methods and consistent clinical staging to improve our understanding of atrophy changes in CKD progression, and analysis of biological sex differences.

Immunosuppressive Therapy and Nutritional Status of Patients after Kidney Transplantation: A Protocol for a Systematic Review

(1) Background: Kidney transplantation is widely recognized as the most effective method of treating end-stage renal disease. Immunosuppressive therapy plays a pivotal role in the treatment of kidney transplant patients, encompassing all patients (except identical twins), and is administered from organ transplantation until the end of its function. The aim of this systematic review is to identify the evidence of the association between immunosuppressive therapy and nutritional status of patients following kidney transplantation. (2) Methods: This protocol has been designed in line with Preferred Items for Systematic Reviews (PRISMA-P). Our search encompasses several databases, including MEDLINE (via PubMed), EMBASE (Elsevier), Scopus and Web of Science. We intend to include observational studies (cross-sectional, case-control, and cohort designs), randomized controlled trials (RCTs), as well as completed and ongoing non-randomized study designs. We will confine our search to studies published in English within the past decade (from inception to 17 February 2023). Qualitative studies, case studies, and conference reports will be excluded. The selection process will be done in Covidence by two independent reviewers. Data extraction will be conducted using a standardized MS Excel template version 16.0. Quality assessment of included studies will be performed using the Cochrane Risk of Bias tool for randomized trials (RoB2), or the Risk of Bias in Non-randomized Studies of Interventions (ROBINS-I) tool. Risk-of-bias plots will be generated using the web application Robvis. Relevant data that have been extracted from eligible studies will be presented in a narrative synthesis. We expect the studies to be too heterogeneous to perform subgroup analyses. (3) Conclusion: This systematic review will offer insights into the evidence regarding association between immunosuppressive therapy and nutritional status of adult patients (18 years of age or older) within the initial year following kidney transplantation. To our knowledge, there is no systematic review addressing that question.

Diagnosis, prevalence, and outcomes of sarcopenia in kidney transplantation recipients: A systematic review and meta-analysis

The prevalence of sarcopenia and its clinical predictors and clinical impact vary among kidney transplant recipients (KTRs), in part because of different diagnostic criteria. This study aimed to assess the reported diagnosis criteria of sarcopenia and compare them in terms of prevalence, clinical predictors, and impact of sarcopenia. The Medline, Embase, and Cochrane Library were searched for the full-length reports published until 28 January 2022. The subgroup analysis, meta-regression, and sensitivity analysis were performed and heterogeneity was assessed using the I² . A total of 681 studies were retrieved, among which only 23 studies (including 2535 subjects, 59.7% men, mean age 49.8 years) were eventually included in the final analysis. The pooled prevalence in these included studies was 26% [95% confidence interval (95% CI): 20-34%, I²  = 93.45%], including 22% (95% CI: 14-32%, I²  = 88.76%) in men and 27% (95% CI: 14-41%, I²  = 90.56%) in women (P = 0.554 between subgroups). The prevalence of sarcopenia diagnosed using low muscle mass was 34% (95% CI: 21-48%, I²  = 95.28%), and the prevalence of using low muscle mass in combination with low muscle strength and/or low physical performance was 21% (95% CI: 15-28%, I²  = 90.37%) (P = 0.08 between subgroups). In meta-regression analyses, the mean age (regression coefficient: 1.001, 95% CI: 0.991-1.011) and percentage male (regression coefficient: 0.846, 95% CI: 0.367-1.950) could not predict the effect size. Lower body mass index (odds ratio (OR): 0.57, 95% CI: 0.39-0.84, I²  = 61.5%), female sex (OR: 0.31, 95% CI: 0.16-0.61, I²  = 0.0%), and higher age (OR: 1.08, 95% CI: 1.05-1.10, I²  = 10.1%) were significantly associated with a higher risk for sarcopenia in KTRs, but phase angle (OR: 0.81, 95% CI: 0.16-4.26, I²  = 84.5%) was not associated with sarcopenia in KTRs. Sarcopenia was not associated with rejections (risk ratio (RR): 0.67, 95% CI: 0.23-1.92, I²  = 12.1%), infections (RR: 1.03, 95% CI: 0.34-3.12, I²  = 87.4%), delayed graft functions (RR: 0.81, 95% CI: 0.46-1.43, I²  = 0.0%), and death (RR: 0.95, 95% CI: 0.32-2.82, I²  = 0.0%) in KRTs. Sarcopenia was found to be very common in KRTs. However, we have not found that sarcopenia had a negative impact on clinical health after kidney transplantation. Large study cohorts and multicentre longitudinal studies in the future are urgently needed to explore the prevalence and prognosis of sarcopenia in kidney transplant patients.

The effect of calcineurin inhibitors on anthropometric measurements in kidney transplant recipients

Background

This study was designed to investigate the effect of calcineurin inhibitors (CNIs), cyclosporine (CsA), and tacrolimus (Tac) on anthropometrics in kidney transplant recipients.

Methods

111 of 128 adult kidney transplant recipients who received post-transplant CNIs were included in this retrospective study. Anthropometrics were recorded in the pre-transplant and post-transplant 4-year follow-up periods (1st, 3rd, 6th, 12th, 24th, 36th and 48th months).

Results

Compared to pre-transplant values, significant increases in body weight and body mass index (between 3rd and 48th months), waist and hip circumferences (between 1st and 48th months), waist-to-hip ratio (between 1st and 3rd or 6th months) and neck circumference (between 1st and 12th or 24th months) were observed in both CsA and Tac groups. A significant increase was noted in post-transplant body fat percentage values for the 3rd to 24th months in the CsA group, whereas for the 24th to 48th months in both CsA and Tac groups. Hip circumferences percentage changes from the pre-transplant period to the 1st, 12th and 24th months were significantly higher in CsA than in the Tac group. At each time point, there was no significant difference in percentage changes for other anthropometric parameters between the CsA and Tac groups. De novo diabetes mellitus developed in 8.3% of the CsA group and 19.1% of the Tac group.

Conclusions

After a successful kidney transplant, anthropometric measurements increase in most recipients. Although the effect of calcineurin inhibitor type on weight gain is unclear, a regression analysis showed that CNI type was not a risk factor for the development of obesity in the 48th month. However, it is helpful to be cautious about its dyslipidemic effect in patients using CsA and the potential hazards of using Tac in patients with a diabetic predisposition.

Arterial Stiffness as a Cardiovascular Risk Factor After Successful Kidney Transplantation in Diabetic and Nondiabetic Patients

BACKGROUND

It is known that kidney transplantation (KTx) decreases mortality rate and increases life expectancy about 10 years compared with dialysis, particularly in patients with diabetes. However, cardiovascular disease is still the most common cause of death after transplantation.

PURPOSE

The evaluation of the cardiovascular risk after successful KTx in diabetic and nondiabetic patients.

METHODS

We enrolled 344 patients after KTx (mean age 52.7 years, M -62.5%). The cohort was divided into 2 groups diabetes (+) and diabetes (-). Arterial stiffness parameters (brachial-ankle and carotid-femoral pulse wave velocity, pulse pressure, pulsatile stress was assessed by an automated oscillometric device. All body composition parameters were evaluated based on bioelectrical impedance analysis and laboratory parameters were obtained from medical files of the patients.

RESULTS

Arterial stiffness parameters were higher in the diabetes (+) compared with diabetes (-) group, significantly. Body mass index was significantly higher in the diabetes (+) group, as well as body fat mass and visceral fat area. In the diabetes (+) group compared with the diabetes (-) group, whole-body phase angle was lower (4.54 vs 4.90 P = .006). Visceral fat area and whole-body phase angle correlated significantly with arterial stiffness parameters.

CONCLUSIONS

The evaluation of arterial stiffness and phase angle is a useful method for identifying patients at high cardiovascular risk. Therefore, we suggest that patients with diabetes after successful KTx due to the baseline high cardiolovascular risk, should be regularly assessed to monitor changes in blood vessels, body composition and undergo dietary intervention.

Nutritional Predictors of Cardiovascular Risk in Patients after Kidney Transplantation-Pilot Study

Asymmetric dimethylarginine (ADMA) is a marker of endothelial damage. Research confirms the association of ADMA with an increased cardiovascular risk (CVR) among kidney transplant recipients (KTRs). Additionally, increased circulating levels of fibroblast growth factor 23 (FGF-23) are associated with pathological cardiac remodeling and vascular alterations. The aim of the study is the analysis of the relationship between ADMA, FGF-23, nutritional, biochemical parameters in healthy subjects and KTRs. 46 KTRs and 23 healthy volunteers at mean age of 50.8 ± 15.4 and 62.5 ± 10.7 years were enrolled. The anthropometric and biochemical parameters such as ADMA, FGF-23, albumin, prealbumin were assessed. Fat tissue mass among KTRs was 30.28 ± 9.73%, lean body mass 64.5 ± 14.8%. Overweight and obesity was presented by 65.2% of recipients. Albumin level was 38.54 ± 3.80 g/L, prealbumin 27.83 ± 7.30 mg/dL and were significantly lower than in the control (p < 0.05). Patients with ADMA > 0.66 µmol/L had a lower concentration of prealbumin, albumin and increased concentration of oxidized low density lipoprotein (oxLDL), high sensitive C-reactive protein (hsCRP) and FGF-23. FGF-23 was significantly higher in patients with higher hsCRP (p < 0.05). KTRs with elevated ADMA had a longer transplantation vintage, lower eGFR and higher albuminuria. Diabetes mellitus (DM) was associated with higher levels of ADMA and FGF-23. Even in stable KTRs a relationship between inflammatory state, nutritional status, graft function and endothelial dysfunction biomarkers was observed.

Evaluation of Dynapenia and Sarcopenia and Their Associations With Serum Insulin-Like Growth Factor-1 Levels in Renal Transplant Recipients

OBJECTIVES

Dynapenia and sarcopenia are related to increased morbidity and mortality in the general population. Chronic kidney disease (CKD) causes sarcopenia and dynapenia with different mechanisms. The aim of this study is to compare the muscle parameters in renal transplant recipients to CKD patients and patients without kidney disease and assess their associations with serum insulin-like growth factor-1 (IGF-1) levels.

METHOD

In total, 120 renal transplant recipients (mean age: 40.4 ± 10.5 years), 60 CKD patients (mean age: 41.9 ± 11.4 years), and 60 control subjects with normal kidney function (mean age: 38.8 ± 9.9 years) were enrolled. Body mass index, hand grip strength, bioelectrical impedance analysis, 6-minute walking test, and serum IGF-1 level were measured and compared between groups. Muscle parameters were evaluated according to The Foundation for the National Institutes of Health Biomarkers Consortium Sarcopenia Project criteria.

RESULTS

IGF-1 levels were highest in the renal transplantation group and lowest in the control group (P = .029). In total, 12.5% of patients in the renal transplantation group (13.3% overweight, 20% obese), 11.6% in the CKD group, and 1.6% in the control group had dynapenia (P = .015). In addition, 8.3% of patients in the CKD group, 3.3% in the renal transplantation group (50% overweight), and none of the patients in the control group had sarcopenia (P = .054). In multivariate analyses, muscle strength was associated with IGF-1 levels in renal transplant recipients (beta = 2.314, t = 3.456, P = .001).

CONCLUSIONS

Serum IGF-1 is closely associated with muscle strength in renal transplant recipients. The negative effects of CKD on muscle system cannot be completely resolved with renal transplantation. Sarcopenic obesity and dynapenic obesity need special attention and therefore body mass index cannot be used as the only parameter to evaluate frailty in renal transplant recipients.

Nutritional Parameters in Early and Late Kidney Transplantation

BACKGROUND

Kidney transplantation (KT) has the advantage of providing a better quality of life and freedom for the patient. However, nutritional changes can occur, with clinical repercussions. The aim of the study was to compare the nutritional status in the initial and late post-KT period.

METHODS

A cross-sectional study was conducted involving 169 outpatients post-KT. Clinical, demographic, biochemical, food intake, handgrip strength (HGS), and anthropometric data were collected from medical records for the first nutritional care after KT. Statistical tests were performed to compare the groups according to the time of KT: early (≤1 year) and late (>1 year). The level of significance adopted was 5%.

RESULTS

The median age of the patients was 46 years (range, 38-57), 50.3% were men, and it was observed that 66.9% underwent KT with a deceased donor. There was a higher prevalence of diabetes mellitus (42.6% vs 23.5%; P = .011), and higher body mass index (28.80 ± 7.26 vs 26.51 ± 6.62 kg/m²; P = .046), arm muscle circumference (25.84 ± 4.63 vs 24.09 ± 3.36 cm; P = .019), and HGS (26.97 ± 10.70 vs 20.21 ± 10.83 kg; P = .010) in patients with late KT. Linear regression analysis showed that at each log of time, there was an increase of 1.90 kg in HGS (P = .045) and 0.48 cm (P = .036) in mid-arm muscle circumference.

CONCLUSION

The present study demonstrated that late kidney transplantation was associated with higher values of body mass index, mid-arm muscle circumference, and HGS.

Novel approaches to sarcopenic obesity and weight management before and after kidney transplantation

PURPOSE OF REVIEW

Although a widely recognized and complex pathophysiological condition, sarcopenic obesity remains less appreciated and may elude diagnosis and workup in both kidney transplant waitlisted candidates and kidney transplant recipients. The lack of consensus definition, and practical diagnostic tools for evaluating waitlisted candidates and transplant recipients are barriers to early detect and initiate therapeutic management for sarcopenic obesity. Although sarcopenia leads to poor clinical outcomes, posttransplant obesity yields conflicting results. Exercise and nutritional managements are common therapies for sarcopenic obese patients; however, surgery weight loss or bariatric surgery in both transplant candidates and potential living kidney donors shows promising benefits for kidney transplant access in waitlist obese candidates but may require to be selected for appropriate patients.

RECENT FINDINGS

Pathogenesis and management for sarcopenia and obesity are interconnected. The benefits of exercise to improve muscle mass and function is clear in waitlist kidney transplant candidates and transplant recipients. However, there are several barriers for those to increase exercise and improve physical activity including patient, provider, and healthcare or environmental factors. The advantages of fat mass reduction to lose weight can promote muscle mass and strength. However, epidemiological data regarding the obesity paradox in dialysis-dependent patients when overnutrition provides survival benefits for this population should be taken into account when performing weight loss especially bariatric surgery.

SUMMARY

Barriers in providing optimal care to kidney transplant waitlisted candidates and transplant recipients may partly result from underdiagnosis of sarcopenic obesity; notwithstanding that this entity has increasingly been more recognized. Mechanistic studies to better understand pathogenesis of sarcopenic obesity will help determine pathogenesis and clinical tools for diagnosis of this entity, which can facilitate further studies related to the outcomes and weight management to ultimately improve kidney transplant outcomes.

Healthy Eating Index of Living Donor Renal Transplantation Recipients During the First Year Posttransplant

BACKGROUND

The aim of this study was to examine the relationship between diet quality and weight gain in kidney transplant recipients from pretransplant baseline through posttransplant at 3 months and 1 year.

METHODS

Data from a prospective, observational cohort study of kidney transplant patients (n = 26) were analyzed. Participants were adult (aged 18-65 years), living donor kidney transplant recipients who were participating in a prospective body composition study. Body weight, body mass index, dietary intake, and Healthy Eating Index scores were used to assess changes in weight, nutrient intake, and diet quality.

FINDINGS

At the time of kidney transplantation, 42% (n = 11) were obese and 27% (n = 7) were overweight. Weight significantly increased from transplantation to 12 months (mean [SD]: 83 [18] kg and 90 [18] kg, respectively; mean change 8.4%, P = .002). At 12 months posttransplant, dietary fat intake significantly increased (P = .033). Body weight was strongly correlated with total dietary fat intake (r = 0.56, P = .003). The Healthy Eating Index total scores at baseline and 1-year posttransplant were not significantly different (45.75 [14.99] and 42.59 [12.70]). Likewise, component scores did not change from pretransplant to posttransplant.

DISCUSSION

Diet quality of transplant recipients was poor both before and after transplantation. Using the Healthy Eating Index confirmed that improvements in food intake are needed. Further research is warranted to identify dietary recommendations for the prevention of excessive weight gain and the potential adverse health complications following kidney transplantation.

Deterioration of presarcopenia and its risk factors following kidney transplantation

BACKGROUND

Sarcopenia is prevalent in patients with chronic kidney disease and is associated with increased mortality; however, limited data are available on whether kidney transplantation can improve muscle wasting. Therefore, the present study aimed to assess changes in body composition before and after kidney transplantation.

METHODS

Between April 2015 and January 2018, 80 de novo consecutive adult patients with end-stage kidney disease who underwent kidney transplantation were prospectively enrolled. Muscle and fat masses were measured via bioelectrical impedance analysis using InBody 770 at  - 2 and 7 days and 3, 6, and 12 months after transplantation. Presarcopenia is characterized by low muscle mass according to the skeletal muscle mass index. Changes in body composition and prevalence of presarcopenia were compared before and after transplantation. Risk factors for presarcopenia were identified using logistic regression analysis.

RESULTS

Muscle mass significantly decreased at 3 months after transplantation. Consequently, the prevalence of presarcopenia was significantly higher after transplantation (3 months: 47.5%, 6 months: 42.5%, and 12 months: 38.8%) than that before transplantation (25.0%). Similarly, the body fat percentage was significantly higher at 3 months after transplantation than that before transplantation. Presarcopenia before transplantation was an independent risk factor for presarcopenia at 12 months after transplantation (odds ratio: 51.8, 95% CI 5.77-464, p < 0.001).

CONCLUSIONS

Muscle wasting deteriorated and body fat percentage increased from 3 months after kidney transplantation. Presarcopenia before transplantation led to presarcopenia after transplantation, which may deteriorate with an increase in body fat percentage.

Good long-term renal graft survival and low incidence of cardiac pathology in adults after short dialysis period and renal transplantation in early childhood - a cohort study

Over the past 30 years, there has been an improvement in both patient and graft survival after pediatric renal transplantation (RTX). Despite this success, these patients still carry an elevated risk for untimely death, partly through premature aging of the vasculature. The aim of this study was thus to investigate the long-term outcome of individuals with RTX in childhood, as well as to explore the cardiovascular health of these adults more than a decade later. We studied 131 individuals who had undergone a RTX between the years 1979 and 2005. Furthermore, left ventricular hypertrophy (LVH), coronary artery calcifications (CAC), and related metabolic factors were investigated in a cross-sectional study including 52 individuals as part of the initial cohort. The mortality rate (n = 131) was 12.2%. The median estimated graft survival was 17.5 years (95% CI 13.6-21.3), being significantly better in children transplanted below the age of 5 years (18.6 vs. 14.3 years, P < 0.01) compared with older ones. CAC were found in 9.8% and LVH in 13% of the patients. Those with cardiac calcifications had longer dialysis vintage and higher values of parathyroid hormone (PTH) during dialysis. Left ventricular mass correlated positively with systolic blood pressure, PTH, and phosphate measured at the time of the study.