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

Association of changes in body composition with all-cause mortality in patients undergoing hemodialysis: A prospective cohort study

OBJECTIVES

This study aimed to explore the effect of longitudinal body composition changes on mortality risk in patients undergoing hemodialysis and identify whether changes in body composition can more accurately predict mortality than baseline status.

METHODS

A prospective cohort study was conducted on 340 patients undergoing hemodialysis. Lean mass and body fat were determined using a bioimpedance spectroscopy (BIS) device and expressed as the lean tissue index (LTI) or fat tissue index (FTI), respectively. The patients were subjected to BIS at baseline and after 1 year. The hazard ratio (HR) for death was calculated using Cox regression analysis.

RESULTS

Among 340 patients, 289 were tested with a repeat BIS. LTI loss and FTI gain were observed in 51.2% and 47.1% of the patients, respectively. Low baseline LTI was a significant predictor of all-cause mortality after adjusting for demographic and biochemical parameters (HR, 2.41; P = 0.047), but not when comorbidities were included in the multivariate analysis. However, after adjusting for various confounding factors, LTI loss (HR, 3.40; P = 0.039) and FTI gain (HR, 4.06; P = 0.024) were independent risk factors for all-cause mortality, and the adjusted HR for LTI loss and FTI gain vs. no LTI loss and no FTI gain was 5.34 (P = 0.016).

CONCLUSIONS

LTI loss and FTI gain, particularly their combination, are important predictors of survival in patients undergoing hemodialysis. Our results emphasize that longitudinal changes in LTI and FTI are more strongly associated with all-cause mortality than single-point values. Therefore, it is important to dynamically assess the muscle and fat tissues and develop potential targeted treatment strategies for this population.

Sarcopenic obesity is associated with adverse outcomes after kidney transplantation: a retrospective cohort study

PURPOSE

Sarcopenia was found to be a poor prognostic factor in kidney transplant recipients, but the role of sarcopenia obesity remains unclear. This study aimed to explore the effect of sarcopenic obesity on kidney transplantation.

METHODS

A retrospective analysis was performed on kidney transplant recipients between 2015 and 2019. Pretransplant CT scans were utilized to assess sarcopenia and visceral obesity. Based on the presence or absence of sarcopenia and visceral obesity, the recipients were classified into four distinct groups.

RESULTS

The recipients were categorized into four groups based on their characteristics: the nonsarcopenic nonobesity group (n = 493, 49.85%), the nonsarcopenic obesity group (n = 248, 25.08%), the sarcopenic nonobesity group (n = 188, 19.01%), and the sarcopenic obesity group (n = 60, 6.07%). Multivariate analysis, identified sarcopenic obesity was as an independent risk factor for mortality following kidney transplantation (adjusted hazard ratio, 5.861; 95% confidence interval [CI]: 1.627-21.108; P = 0.007). Additionally, sarcopenic obesity was associated with an increased risk of delayed graft function (adjusted odds ratio [aOR], 3.342; 95% CI 1.421-7.745; P = 0.005), perioperative incision infection (aOR, 9.654; 95% CI 1.572-60.648; P = 0.011), perioperative pulmonary infection (aOR, 2.557; 95% CI 1.208-5.215; P = 0.011), and readmission within 3 months (aOR, 2.100; 95% CI 1.051-4.017; P = 0.029). While sarcopenic obesity was found to be associated with impaired graft renal function, it did not show a significant correlation with death-censored graft survival or quality of life.

CONCLUSION

The presence of sarcopenic obesity prior to kidney transplantation represents an independent risk factor for mortality, and it is also linked to a range of unfavorable outcomes.

Comprehensive review: Frailty in pancreas transplant candidates and recipients

Well-selected patients with kidney disease and diabetes mellitus who undergo simultaneous kidney-pancreas transplantation often experience dramatic improvements in quality of life and long-term survival compared to those who remain on medical therapy. Over the past several years the importance of frailty in the pancreas transplant candidate and recipient populations has grown. More patients with advanced age have entered the waitlist, and complications from prolonged diabetes, even in younger patients, have created increased evidence of risk for frailty. Given these concerns, and the broad challenges facing pancreas transplantation volumes overall, we generated this review to help establish the impact and implications. We summarize the interplay of immunological factors, aging, environmental factors, diabetes mellitus, and chronic kidney disease that put these patients at risk for frailty. We discuss its measurement and recommend a combination of two instruments (both well-validated and one entirely objective). We describe the outcomes for patients before and after pancreas transplantation who may have frailty, and what interventions can be taken to mitigate its effects. Broader investigation into frailty in the pancreas transplant population is needed to better understand how to select patients for pancreas transplantation and to how manage its consequences thereafter.

Muscle mass, muscle strength and mortality in kidney transplant recipients: results of the TransplantLines Biobank and Cohort Study

BACKGROUND

Survival of kidney transplant recipients (KTR) is low compared with the general population. Low muscle mass and muscle strength may contribute to lower survival, but practical measures of muscle status suitable for routine care have not been evaluated for their association with long-term survival and their relation with each other in a large cohort of KTR.

METHODS

Data of outpatient KTR ≥ 1 year post-transplantation, included in the TransplantLines Biobank and Cohort Study (ClinicalTrials.gov Identifier: NCT03272841), were used. Muscle mass was determined as appendicular skeletal muscle mass indexed for height2 (ASMI) through bio-electrical impedance analysis (BIA), and by 24-h urinary creatinine excretion rate indexed for height2 (CERI). Muscle strength was determined by hand grip strength indexed for height2 (HGSI). Secondary analyses were performed using parameters not indexed for height2. Cox proportional hazards models were used to investigate the associations between muscle mass and muscle strength and all-cause mortality, both in univariable and multivariable models with adjustment for potential confounders, including age, sex, body mass index (BMI), estimated glomerular filtration rate (eGFR) and proteinuria.

RESULTS

We included 741 KTR (62% male, age 55 ± 13 years, BMI 27.3 ± 4.6 kg/m2), of which 62 (8%) died during a median [interquartile range] follow-up of 3.0 [2.3-5.7] years. Compared with patients who survived, patients who died had similar ASMI (7.0 ± 1.0 vs. 7.0 ± 1.0 kg/m2; P = 0.57), lower CERI (4.2 ± 1.1 vs. 3.5 ± 0.9 mmol/24 h/m2; P < 0.001) and lower HGSI (12.6 ± 3.3 vs. 10.4 ± 2.8 kg/m2; P < 0.001). We observed no association between ASMI and all-cause mortality (HR 0.93 per SD increase; 95% confidence interval [CI] [0.72, 1.19]; P = 0.54), whereas CERI and HGSI were significantly associated with mortality, independent of potential confounders (HR 0.57 per SD increase; 95% CI [0.44, 0.81]; P = 0.002 and HR 0.47 per SD increase; 95% CI [0.33, 0.68]; P < 0.001, respectively), and associations of CERI and HGSI with mortality remained independent of each other (HR 0.68 per SD increase; 95% CI [0.47, 0.98]; P = 0.04 and HR 0.53 per SD increase; 95% CI [0.36, 0.76]; P = 0.001, respectively). Similar associations were found for unindexed parameters.

CONCLUSIONS

Higher muscle mass assessed by creatinine excretion rate and higher muscle strength assessed by hand grip strength are complementary in their association with lower risk of all-cause mortality in KTR. Muscle mass assessed by BIA is not associated with mortality. Routine assessment using both 24-h urine samples and hand grip strength is recommended, to potentially target interdisciplinary interventions for KTR at risk for poor survival to improve muscle status.

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.

Donor obesity and weight gain after transplantation: two still overlooked threats to long-term graft survival

The effect of donor obesity on kidney transplantation success has long been an overlooked clinical research area. Even though there is no strict guideline in most countries prohibiting donation from obese individuals, most candidates with a body mass index >35-40 kg/m² are rejected due to concerns regarding long-term renal functional deterioration in the donor. The effects of excessive fat mass on renal function and allograft survival have been analysed by several longitudinal and follow-up studies. These studies have documented the deleterious effect on long-term graft outcomes of excessive body mass in living kidney donors and de novo obesity or pre-existing obesity worsening after transplantation on kidney outcomes. However, there is a paucity of clinical trials aimed at countering overweight and obesity in living and deceased kidney donors and in transplant patients. In this review we will briefly discuss the mechanism whereby fat excess induces adverse kidney outcomes and describe the effects on graft function and survival in living obese donors.