Percentages of water, muscle, and bone decrease and lipid increases in early period after successful kidney transplantation: a body composition analysis

Assessing Patients beyond the Simple Optics of BMI: The Concomitant Role of Sarcopenia and BMI in Predicting Kidney Transplant Outcomes

BACKGROUND

Body composition is associated with prognosis in many clinical settings, and patients undergoing kidney transplantation are often high risk with multiple comorbidities. We aimed to assess the effect of sarcopenia and body composition on transplant outcomes.

METHODS

We performed a retrospective analysis of 274 kidney transplants with CT scans within 3 years of transplantation. The skeletal muscle index (SMI) at the L3 vertebrae was used to evaluate sarcopenia (SMI < 40.31 cm2/m2 in males, <30.88 cm2/m2 in females). Sarcopenia, body mass index (BMI), and the visceral-to-subcutaneous-fat ratio (VSR) were assessed separately. We also used a composite BMI/sarcopenia measurement in four patient groups: BMI < 25/Non-Sarcopenic, BMI < 25/Sarcopenic, BMI > 25/Non-Sarcopenic, and BMI > 25/Sarcopenic. The outcomes measured were eGFR (1 and 3 months; and 1, 3, and 5 years), delayed graft function (DGF), rejection, major adverse cardiovascular events (MACE), and post-operative complications.

RESULTS

Sarcopenia was associated with an increased 1-year risk of MACE (OR 3.41, p = 0.036). BMI alone had no effect on function, DGF, MACE, or on other complications. High VSR was associated with a lower risk of DGF (OR 0.473, p = 0.016). When sarcopenia and BMI were assessed together, the BMI > 25/sarcopenic patients had the poorest outcomes, with increased risk of MACE (OR 26.06, p = 0.001); poorer eGFR at 1, 3, 12, and 36 months; (p < 0.05 at all timepoints), and poorer graft survival (p = 0.002).

CONCLUSIONS

Sarcopenia alone is associated with an increased risk of MACE. Overweight sarcopenic patients are additionally at increased risk of graft loss and have poorer graft function for up to three years.

Body fat predicts urinary tract infection in kidney transplant recipients: a prospective cohort study

BACKGROUND

The association between obesity and infectious diseases is increasingly reported in the literature. There are scarce studies on the association between obesity and urinary tract infection after kidney transplantation (KTx). These studies defined obesity based on body mass index, and their results were conflicting. The present study aimed to evaluate this association using bioelectrical impedance analysis for body composition evaluation, and obesity definition.

METHODS

A single-center cohort study was conducted. Demographic, clinical, anthropometric, and laboratory data were collected at KTx admission, and bioelectrical impedance analysis was performed to measure the visceral fat area, waist circumference, and total fat mass. The occurrence of urinary tract infection (symptomatic bacteriuria and/or histological evidence of pyelonephritis) was evaluated within three months after KTx.

RESULTS

Seventy-seven patients were included in the cohort, and 67 were included in the final analysis. Urinary tract infection was diagnosed in 23.9% of the transplanted patients. Waist circumference (HR: 1.053; 95% CI 1.005-1.104; p = 0.032), visceral fat area (HR: 1.015; 95% CI 1.003-1.027; p = 0.014), and total fat mass (HR: 1.075; 95% CI 1.008-1.146; p = 0.028) were associated with urinary tract infection occurrence after KTx, using Cox regression models. Patients with high waist circumference (above 102 cm for men and above 88 cm for women) had a 4.7 times higher risk of a urinary tract infection than those with normal waist circumference (HR: 4.726; 95% CI 1.267-17.630; p = 0.021). Kaplan-Meier curves showed that patients with high waist circumference, high visceral fat area, and high total fat mass had more urinary tract infections (Log-rank test p = 0.014, p = 0.020, and p = 0.018, respectively). Body mass index was not able to predict urinary tract infection in the study sample.

CONCLUSIONS

Waist circumference, visceral fat area, and total fat mass, assessed by bioelectrical impedance analysis, were predictors of urinary tract infection risk within the first three months after KTx.

Association of habitual coffee consumption with obesity, sarcopenia, bone mineral density and cardiovascular risk factors: A two-year follow-up study in kidney transplant recipients

BACKGROUND & AIMS

Recent evidence suggests that moderate coffee intake is associated with multiple health benefits, including lower risk of obesity, sarcopenia and cardiovascular disease (CVD) in the general population. However, to date, no study has evaluated these associations in kidney transplant recipients (KTR). The aim of the present study was to evaluate the association of habitual coffee consumption with obesity, sarcopenia, bone mineral density and CVD risk factors in KTR.

METHODS

This prospective 2 years-follow-up study included 170 KTR (59% men) aged 49.5 (42.0-57.0) years. At baseline participants were submitted to the following evaluations: clinical, laboratorial, dietary intake (including coffee), muscle strength, anthropometric and body composition by bioelectrical impedance analysis (BIA) and dual-energy X-ray absorptiometry (DXA). After two years 163 KTR were re-evaluated by anthropometry, BIA and muscle strength. Sarcopenia was defined according to EWGSOP2. Risk factors for CVD were hypertension, diabetes mellitus, dyslipidemia, metabolic syndrome and hyperhomcysteinemia. Participants were stratified according to coffee intake: 0 or 1 time/day (Gr0-1) and 2 or 3 times/day (Gr2-3).

RESULTS

The median coffee consumption was 200 (150-250)mL/day and 112 (71-155)mL/1000 kcal/day. At baseline, Gr2-3 vs. Gr0-1 exhibited significantly higher values of waist circumference, waist-to-height ratio (WHtR) and presented a higher odds ratio for central obesity according to WHtR (2.68; 95%CI:1.19-6.02; p = 0.02) after adjustment for confounders. Coffee consumption (mL/1000 kcal/day) showed, even after adjustment for confounders, (1) a positive association with all parameters of body adiposity (anthropometry, BIA and DXA) and (2) a negative association with muscle quality index. After two years, coffee intake (mL/1000 kcal/day) at baseline presented a positive correlation with changes in fat mass (kg) by BIA (r = 0.22, p = 0.01) after adjustment for confounders.

CONCLUSION

This study suggests that in KTR, higher coffee consumption is associated with increased adiposity, specially, central adiposity and lower muscle quality, but is not related with the other evaluated parameters.

Predicting physical activity in kidney transplant recipients: an application of the Health Action Process Approach model

Despite numerous physical, psychological, and social benefits of physical activity (PA), few kidney transplant recipients (KTRs) positively participate in PA. It is essential to understand the influencing factors of PA in KTRs. This study aimed to apply the Health Action Process Approach (HAPA) model to explore the influencing factors of PA in KTRs. This was a prospective study involving 320 participants. Pre-actional self-efficacy, outcome expectancies, risk perception, social support, PA intention, and demographic and clinical data were measured at Time 1. Coping self-efficacy, planning, recovery self-efficacy, and PA behavior were assessed 3 months later. The hypothesized relationships were examined by structural equation modeling. Findings revealed significant direct effects of pre-actional self-efficacy, negative outcome expectancies, positive outcome expectancies, and social support on intention. Planning and recovery self-efficacy were significant predictors of PA. The HAPA model provided a validated and useful framework for predicting the factors influencing PA behavior in KTRs.

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.

Skeletal Muscle Phenotype in Patients Undergoing Long-Term Hemodialysis Awaiting Kidney Transplantation

BACKGROUND AND OBJECTIVES

Age and comorbidity-related sarcopenia represent a main cause of muscle dysfunction in patients on long-term hemodialysis. However, recent findings suggest muscle abnormalities that are not associated with sarcopenia. The aim of this study was to isolate functional and cellular muscle abnormalities independently of other major confounding factors, including malnutrition, age, comorbidity, or sedentary lifestyle, which are common in patients on maintenance hemodialysis. To overcome these confounding factors, alterations in skeletal muscle were analyzed in highly selected patients on long-term hemodialysis undergoing kidney transplantation.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

In total, 22 patients on long-term hemodialysis scheduled for kidney transplantation with few comorbidities, but with a long-term uremic milieu exposure, and 22 age, sex, and physical activity level frequency-matched control participants were recruited. We compared biochemical, functional, and molecular characteristics of the skeletal muscle using maximal voluntary force and endurance of the quadriceps, 6-minute walking test, and muscle biopsy of vastus lateralis. For statistical analysis, mean comparison and multiple regression tests were used.

RESULTS

In patients on long-term hemodialysis, muscle endurance was lower, whereas maximal voluntary force was not significantly different. We observed a transition from type I (oxidative) to type II (glycolytic) muscle fibers, and an alteration of mitochondrial structure (swelling) without changes in DNA content, genome replication (peroxisome proliferator activator receptor γ coactivator-1α and mitochondrial transcription factor A), regulation of fusion (mitofusin and optic atrophy 1), or fission (dynamin-related protein 1). Notably, there were autophagosome structures containing glycogen along with mitochondrial debris, with a higher expression of light chain 3 (LC3) protein, indicating phagophore formation. This was associated with a greater conversion of LC3-I to LC3-II and the expression of Gabaralp1 and Bnip3l genes involved in mitophagy.

CONCLUSIONS

In this highly selected long-term hemodialysis population, a low oxidative phenotype could be defined by a poor endurance, a fiber-type switch, and an alteration of mitochondria structure, without evidence of sarcopenia. This phenotype could be related to uremia through the activation of autophagy/mitophagy.

CLINICAL TRIAL REGISTRATION NUMBERS

NCT02794142 and NCT02040363.

Accuracy of surrogate methods to estimate skeletal muscle mass in non-dialysis dependent patients with chronic kidney disease and in kidney transplant recipients

BACKGROUND & AIMS

Bioelectrical impedance analysis (BIA) and anthropometric predictive equations have been proposed to estimate whole-body (SMM) and appendicular skeletal muscle mass (ASM) as surrogate for dual energy X-ray absorptiometry (DXA) in distinct population groups. However, their accuracy in estimating body composition in non-dialysis dependent patients with chronic kidney disease (NDD-CKD) and kidney transplant recipients (KTR) is unknown. The aim of this study was to investigate the accuracy and reproducibility of BIA and anthropometric predictive equations in estimating SMM and ASM compared to DXA, in NDD-CKD patients and KTR.

METHODS

A cross-sectional study including adult NDD-CKD patients and KTR, with body mass index (BMI) ≥18.5 kg/m². ASM and estimated SMM were evaluated by DXA, BIA (Janssen, Kyle and MacDonald equations) and anthropometry (Lee and Baumgartner equations). Low muscle mass (LowMM) was defined according to cutoffs proposed by guidelines for ASM, ASM/height² and ASM/BMI. The best performing equation as surrogate for DXA, considering both groups of studied patients, was defined based in the highest Lin's concordance correlation coefficient (CCC) value, the lowest Bland-Altman bias (<1.5 kg) combined with the narrowest upper and lower limits of agreement (LoA), and the highest Cohen's kappa values for the low muscle mass diagnosis.

RESULTS

Studied groups comprised NDD-CKD patients (n = 321: males = 55.1%; 65.4 ± 13.1 years; eGFR = 28.8 ± 12.7 ml/min) and KTR (n = 200: males = 57.7%; 47.5 ± 11.3 years; eGFR = 54.7 ± 20.7 ml/min). In both groups, the predictive equations presenting the best accuracy compared to DXA were SMM-BIA-Janssen (NDD-CKD patients: CCC = 0.88, 95%CI = 0.83-0.92; bias = 0.0 kg; KTR: CCC = 0.89, 95%CI = 0.86-0.92, bias = -1.2 kg) and ASM-BIA-Kyle (NDD-CKD patients: CCC = 0.87, 95%CI = 0.82-0.90, bias = 0.7 kg; KTR: CCC = 0.89, 95%CI = 0.86-0.92, bias = -0.8 kg). In NDD-CKD patients and KTR, LowMM frequency was similar according to ASM-BIA-Kyle versus ASM-DXA. The reproducibility and inter-agreement to diagnose LowMM using ASM/height² and ASM/BMI estimated by BIA-Kyle equation versus DXA was moderate (kappa: 0.41-0.60), in both groups. Whereas female patients showed higher inter-agreement (AUC>80%) when ASM/BMI index was used, male patients presented higher AUC (70-74%; slightly <80%) for ASM/height² index.

CONCLUSIONS

The predictive equations with best performance to assess muscle mass in both NDD-CKD patients and KTR was SMM-BIA by Janssen and ASM-BIA by Kyle. The reproducibility to diagnose low muscle mass, comparing BIA with DXA, was high using ASM/BMI in females and ASM/height² in males in both groups.

Physical Activity and Cardiovascular Risk among Kidney Transplant Patients

PURPOSE

Research examining the relationship between physical activity (PA) and cardiovascular disease (CVD) risk factors among kidney transplant recipients (KTR) is limited. Accordingly, we sought to 1) describe the levels of PA in KTR and 2) analyze the associations between PA levels and CVD risk factors in KTR.

METHODS

Baseline data from KTR participants in a large multiethnic, multicenter trial (the Folic Acid for Vascular Outcome Reduction in Transplantation) were examined. PA was categorized in tertiles (low, moderate, and high) derived from a modified PA summary score from the Yale Physical Activity Survey. CVD risk factors were examined across levels of PA by ANOVA, Kruskal-Wallis rank test, and hierarchical multiple regression.

RESULTS

The 4034 participants were 37% female (mean ± SD = 51.9 ± 9.4 yr of age, 75% White, 97% with stage 2T-4T chronic kidney disease, and 20% with prevalent CVD. Participants in the "high" PA tertile reported more vigorous PA and walking, compared with participants in moderate and low tertiles (both P < 0.001). No differences were observed in daily household, occupational, or sedentary activities across PA tertiles. More participants in the "low" PA tertile were overweight/obese, had a history of prevalent diabetes, and/or had CVD compared with more active participants (all P < 0.001). Hierarchical modeling revealed that younger age (P = 0.002), cadaveric donor source (P = 0.006), shorter transplant vintage (P = 0.025), lower pulse pressure (P < 0.001), and no history of diabetes (P < 0.001) were associated with higher PA scores.

CONCLUSION

The most active KTR engaged in more intentional exercise. Lower levels of PA were positively associated with more CVD risk factors. Higher PA levels were associated with younger age and with more positive KTR outcomes.

High abdominal adiposity and low phase angle in overweight renal transplant recipients

Obesity is associated with increased risk of cardiovascular disease (CVD). Body mass index (BMI) is the most used parameter for obesity screening. However, the evaluation of CVD risk in overweight individuals should include the assessment of body fat distribution and body composition. Renal transplant recipients (RTR) have a high CVD risk and frequently present weight gain and loss of lean mass. The aim of this study was to evaluate body fat distribution and body composition in overweight RTR. This cross-sectional study was conducted with 86 RTR and 86 hypertensive individuals (comparison group, CG) presenting BMI 25-35 Kg/m² and 45-70 years. Anthropometric evaluation included BMI, waist circumference, waist-to-height ratio, and a body shape index. Body composition was evaluated with bioelectrical impedance analysis (BIA). Glomerular filtration rate was estimated (eGFR) by CKD-EPI equation. RTR group (RTRG) and CG presented similar age and BMI. RTRG when compared to CG presented lower percentage of women and eGFR; higher central adiposity; and lower values of reactance, intracellular water, body cell mass and phase angle, more consistently observed in women. This study suggests that overweight RTR present higher abdominal adiposity and impairment in BIA parameters that are sensitive indicators of impaired membrane integrity, water distribution, and body cell mass.

A Randomized Controlled Trial of an Intensive Nutrition Intervention Versus Standard Nutrition Care to Avoid Excess Weight Gain After Kidney Transplantation: The INTENT Trial

OBJECTIVE

Excessive weight gain is common after kidney transplantation and increases cardiovascular risk. The aim of this randomized controlled trial was to determine whether an intensive nutrition and exercise intervention delivered alongside routine post-transplant care would reduce post-transplant weight gain.

DESIGN

Single-blind, randomized controlled trial.

SUBJECTS AND SETTING

Adult kidney transplant recipients at a regional transplant center were recruited during routine outpatient clinic visits in the first month after transplant. Patients with a body mass index >40 kg/m² or <18.5 kg/m², severe malnutrition, or ongoing medical complications were excluded.

INTERVENTION

Participants were randomized to intensive nutrition intervention (individualized nutrition and exercise counselling; 12 dietitian visits; 3 exercise physiologist visits over 12 months) or to standard nutrition care (guideline based; 4 dietitian visits).

MAIN OUTCOME MEASURES

The primary outcome was weight at 6 months after transplant adjusted for baseline weight, obesity, and gender, analyzed using analysis of covariance. The secondary outcomes included body composition, biochemistry, quality of life, and physical function.

RESULTS

Thirty-seven participants were randomized to the intensive intervention (n = 19) or to standard care (n = 18); one intensive group participant withdrew before baseline. Weight increased between baseline, 6 and 12 months (78.0 ± 13.7 [standard deviation], 79.6 ± 13.0 kg, 81.6 ± 12.9 kg; mean change 4.6% P < .001) but at 6 months did not differ significantly between the groups: 77.0 ± 12.4 kg (intensive); 82.2 ± 13.4 kg (standard); difference in adjusted means 0.4 kg (95% confidence interval: -2.2 to 3.0 kg); analysis of covariance P = .7. No between-group differences in secondary outcomes were observed. Across the whole cohort, total body protein and physical function (gait speed, sit to stand, grip strength, physical activity, and quality of life [all but 2 domains]) improved. However, adverse changes were seen for total body fat, HbA1c, and fasting glucose across the cohort.

CONCLUSIONS

Kidney transplant recipients in the first year after transplant did not benefit from an intensive nutrition intervention compared with standard nutrition care, although weight gain was relatively modest in both groups.

Assessment of physical performance and body composition in male renal transplant patients

BACKGROUND

Renal transplant (RTX) recipients seem to experience a better quality of life compared to dialysis patients. However, the factors responsible for this positive effect are not completely defined. Conceivably, a change in the physical performance of these patients could play a role.

METHODS

To assess this, we measured: (1) waist circumference, fat mass and appendicular fat-free mass (aFFM) by dual-energy X-ray densitometry, (2) physical performance with the Short Physical Performance Battery, and (3) muscle strength with the handgrip test, in 59 male RTX, 11 chronic kidney disease in conservative treatment (CKD) and 10 peritoneal dialysis (PD) patients.

RESULTS

Surprisingly, anthropometric characteristics and body composition were similar among the three groups. However, despite a low aFFM, muscle strength was higher in stable RTX recipients > 5 years after transplantation than in dialyzed patients. Instead, CKD (wait-listed for RTX) had similar muscle strength to RTX patients. Waist circumference in RTX recipients showed a redistribution of body fat with increased central adipose tissue allocation compared to PD. At linear regression analysis, age, weight, height, aFFM, hemoglobin and transplant age were independent predictors of handgrip strength, explaining about 37% of the variance. Age and transplant age accounted for 18 and 12% of variance, respectively.

CONCLUSIONS

Our study demonstrates, for the first time, that clinically stable RTX recipients have greater muscle strength than dialyzed patients and suggests that the handgrip test could be an effective and easy-to-perform tool to assess changes in physical performance in this large patient population.

Rising Need for Health Education Among Renal Transplant Patients and Caregiving Competence in Care Providers

Background:

Health education positively affects the efficacy of self-management and should be carried out according to the status of patients’ needs, knowledge, and the competence of the primary caregivers.

Objectives:

This study was to investigate the needs of health education knowledge in transplant patients and the competence of the primary caregivers.

Methods:

This is a cross-sectional study using a convenient sampling approach. Self-report questionnaires were applied to 351 renal transplantation patients and their primary caregivers.

Results:

Three-hundred nine valid questionnaires were included in the analysis. The intensive care unit environment, stress coping strategies, the operation procedure, anesthesia and adverse reactions, and hand hygiene were the 5 most poorly understood aspects in health education. Stress coping strategies, at-home self-monitoring of health, pulmonary infection prevention, dietary needs, and anesthesia and other adverse reactions were the top 5 health education needs. Decision and self-efficacy were the weakest caregiving competence. Significant positive correlations were observed between health education knowledge level and caregiving competence in the primary caregivers. Marriage, education level, career, expense reimbursement, and residence significantly contributed to the health education demand questionnaire model, whereas gender, age, ethnic group, education level, career, and expense reimbursement significantly contributed to health education knowledge questionnaire model ( P < .05).

Conclusion:

The renal transplant patients and their primary caregivers need health education on the intensive care unit environment, stress coping strategies, the operation procedure, and anesthesia and other adverse reactions. The primary caregivers need training in decision-making and self-efficacy.

Posttransplant sarcopenia: an underrecognized early consequence of liver transplantation

Liver transplantation is believed to reverse the clinical and metabolic abnormalities of cirrhosis. Reduced skeletal muscle mass or sarcopenia contributes to increased mortality and adverse consequences of cirrhosis. Failure of reversal of sarcopenia of cirrhosis after liver transplantation is not well recognized. Six temporally, geographically, and methodologically distinct follow-up studies in 304 cirrhotics reported conflicting data on changes in indirect measures of skeletal muscle mass after transplantation. Distinct measures of body composition but not skeletal muscle mass were used and did not focus on the clinical consequences of sarcopenia after transplantation. A number of studies reported an initial rapid postoperative loss of lean mass followed by incomplete recovery with a maximum follow-up of 2 years. Posttransplant sarcopenia may be responsible for metabolic syndrome and impaired quality of life after liver transplantation. Potential reasons for failure to reverse sarcopenia after liver transplantation include use of immunosuppressive agents [mammalian target of rapamycin (mTOR) and calcineurin inhibitors] that impair skeletal muscle growth and protein accretion. Repeated hospitalizations, posttransplant infections, and renal failure also contribute to posttransplant sarcopenia. Finally, recovery from muscle deconditioning is limited by lack of systematic nutritional and physical-activity-based interventions to improve muscle mass. Despite the compelling data on sarcopenia before liver transplantation, the impact of posttransplant sarcopenia on clinical outcomes is not known. There is a compelling need for studies to examine the mechanisms and consequences of sarcopenia post liver transplantation to permit development of therapies to prevent and reverse this disorder.

Is 3-compartment bioimpedance spectroscopy useful to assess body composition in renal transplant patients?

BACKGROUND

Metabolic disorders, in particular weight gain, increase cardiovascular mortality risk and can cause serious problems after renal transplantation. Weight and body mass index are imprecise indicators of nutritional status. Accurate determination of the body composition of renal transplant patients is essential; therefore, a simple tool that allows appropriate patient monitoring is crucial.

DESIGN

A new device, the Body Composition Monitor (BCM, Fresenius Medical Care, Bad Homburg, Germany), expresses body weight in terms of adipose tissue, lean tissue mass, and excess fluid. We compared the performance of this 3-compartment model with dual-energy X-ray absorptiometry (DEXA) as a reference method in determining body composition in a renal transplant population.

SUBJECTS

Thirty-three clinically stable renal transplant patients were studied. Bland-Altman plots and Passing-Bablok regression were used to compare methods.

RESULTS

Mean lean mass was 51.8 ± 12.3 kg with DEXA and 39.0 ± 9.9 kg with BCM. Despite the Passing-Bablok regression failing to find significant differences, the predictive value of BCM for DEXA was poor. Mean fat mass was 19.4 ± 9.7 kg with DEXA and 30.0 ± 16.0 kg with BCM. The slope of the regression line of BCM over DEXA significantly differed from 1.

CONCLUSION

We conclude that, in this population, these methods cannot be substituted for one another.