The obesity paradox and mortality associated with surrogates of body size and muscle mass in patients receiving hemodialysis

The role of lean body mass in predicting mortality in hemodialysis patients across different age groups

Lean body mass (LBM) serves as an indicator of muscle mass in body composition. Recently, studies have revealed increased mortality rates in dialysis patients with low LBM. However, studies analyzing the impact of age on LBM and mortality in dialysis patients remain limited. This study analyzed data from 26,625 adult hemodialysis patients registered in the Korean Society of Nephrology (KSN) registry from 2001 to 2020. We used the lean body mass index (LBMI), standardized by the square of height, to normalize lean body mass. Patients were first categorized by age group (20-49, 50-69, and ≥ 70 years). Subsequently, patients were categorized into quartile groups based on their LBMI (≤ 15.55, 15.55 < LBMI ≤ 16.52, 16.52 < LBMI ≤ 17.59, and > 17.59). This study revealed that the lowest LBMI group (≤ 15.55) was associated with decreased survival across all age groups, with this trend being particularly prominent in the older age groups. Within the 20-49 age group, factors such as diabetes exhibited a notable influence on mortality rates among hemodialysis patients. In the age group over 50, a low LBMI (≤ 15.55) had a greater impact on mortality rates in hemodialysis patients than diabetes. Understanding the importance of LBM in older patients undergoing dialysis is crucial for improving their prognosis.

Effect of omega-3 fatty acids supplementation on muscle mass, fat mass, and visceral fat of hemodialysis patients; A randomized clinical trial

OBJECTIVES

Several studies demonstrated the benefits of omega-3 fatty acids supplementation in chronic kidney disease (CKD) patients. The objective of this study was to investigate the effect of omega-3 fatty acids supplementation in body composition, specifically on the lean body mass and fat mass in hemodialysis patients.

METHODS

In this randomized, double-blind, placebo-controlled clinical trial, a total of 120 end-stage renal disease (ESRD) patients were randomly allocated into two groups. The intervention group has taken three grams of omega-3 fatty acids daily while the placebo group received three grams of medium chain triglycerides (MCT) as a placebo for a total of 2 months. The changes in the body mass index (BMI) and body composition (fat mass, muscle, and visceral fat) were assessed at baseline and following the intervention.

RESULTS

No significant difference was found in the mean of BMI, FAT, muscle, and visceral fat in the intervention group compared to the control group after the intervention. After two months of omega-3 fatty acid supplementation, the study found no statistically significant impact of omega-3 fatty acids supplementation on various indices of body composition. The effect of ω-3 supplementation in reducing visceral fat was close to significant (p=0.08).

CONCLUSIONS

This study suggests that there is currently inadequate evidence to support the effect of omega-3 fatty acid supplementation in improving anthropometric measurements in patients with CKD, except a partial effect on visceral fat. Further large-scale and long-term clinical trials are needed to confirm the present results.

Moderate BMI accumulation modified associations between blood benzene, toluene, ethylbenzene and xylene (BTEX) and phenotypic aging: mediating roles of inflammation and oxidative stress

The associations between blood benzene, toluene, ethylbenzene, and xylenes (BTEX) and biological aging among general adults remain elusive. The present study comprised 5780 participants from the National Health and Nutrition Examination Survey 1999-2010. A novel measure of biological aging, phenotypic age acceleration (PhenoAge.Accel), derived from biochemical markers was calculated. Weighted generalized linear regression and weighted quantile sum regression (WQS) were utilized to assess the associations between BTEX components and mixed exposure, and PhenoAge.Accel. The mediating roles of systemic immune-inflammation index (SII) and oxidative stress indicators (serum bilirubin and gamma-glutamyl transferase), along with the modifying effects of body mass index (BMI) were also examined. In the single-exposure model, the highest quantile of blood benzene (b = 0.89, 95%CI: 0.58 to 1.20), toluene (b = 0.87, 95%CI: 0.52 to 1.20), and ethylbenzene (b = 0.80, 95%CI: 0.46 to 1.10) was positively associated with PhenoAge.Accel compared to quantile 1. Mixed-exposure analyses revealed a consistent positive association between BTEX mixed exposure and PhenoAge.Accel (b = 0.88, 95%CI: 0.56 to 1.20), primarily driven by benzene (92.78%). The association between BTEX and PhenoAge.Accel was found to be partially mediated by inflammation and oxidative stress indicators (ranging from 3.2% to 13.7%). Additionally, BMI negatively modified the association between BTEX mixed exposure and PhenoAge.Accel, with a threshold identified at 36.2 kg/m^2. Furthermore, BMI negatively moderated the direct effect of BTEX mixed exposure on PhenoAge.Accel in moderated mediation models, while positively modified the link between SII and PhenoAge.Accel in the indirect path (binteraction = 0.04, 95%CI: 0.01 to 0.06). Overall, BTEX mixed exposure was associated with PhenoAge.Accel among US adults, with benzene may have reported most contribution, and inflammation and oxidative damage processes may partially explain this underlying mechanism. The study also highlighted the potential benefits of appropriate BMI increased. Additional large-scale cohort studies and experiments were necessary to substantiate these findings.

Relationship of body mass index and kidney outcomes in patients with primary glomerulonephritis: A systematic review and meta-analysis

BACKGROUND

Primary glomerulonephritis, is a major contributor to the development of chronic kidney disease and end-stage renal disease. Previous studies on the relationship between overweight/obesity with primary glomerulonephritis in the chronic kidney disease was inconsistent. This study aimed to systematically review and meta-analyze the relationship between body mass index and adverse kidney outcomes in patients with primary glomerulonephritis.

METHODS

PubMed, Embase, the Cochrane Library, and the China National Knowledge Infrastructure were searched. Patients were divided into an overweight/obesity group (group O) and a non-overweight/obesity group (group N) according to their body mass index values.

RESULTS

Twenty-six studies with 11,038 patients were selected. Patients in group O had deteriorated baseline characteristics, including worse baseline estimated glomerular filtration rate (weighted mean differences [WMD] = -5.99), higher Scr (WMD = 7.34), uric acid (WMD = 47.53), 24-hour proteinuria (WMD = 0.40), and a higher prevalence rate of hypertension (odds ratio, OR = 2.70) and diabetes mellitus (OR = 2.644). On the histopathologic level, patients in group O had a significantly lower total glomerular number (WMD = -2.30); however, no difference was observed in mesangial cell proliferation, endocapillary hypercellularity, crescents, sclerosis, and tubular atrophy/interstitial fibrosis between the 2 groups. The incidence of adverse renal outcomes in the 2 groups was similar (OR = 0.96). The meta-analysis of hazard ratios from Cox regressions indicated a strong association between overweight/obesity and poor renal outcomes in glomerulonephritis (HR = 1.17).

CONCLUSION

Overweight/obesity glomerulonephritis patients had remarkably poor baseline clinicopathological characteristics. Being overweight or obesity would likely impact the progression of primary glomerulonephritis but not serious enough to contribute to significant poor renal outcomes, which could be prevented by aggressive therapy.

The epidemiology and microbiology of central venous catheter related bloodstream infections among hemodialysis patients in the Philippines: a retrospective cohort study

BACKGROUND

Despite efforts to improve the management of catheter-related bloodstream infections (CRBSI) in literature, temporary CVCs continue to be used for maintenance hemodialysis outside of acute care settings, particularly in the Philippines.

METHODS

We conducted a retrospective cohort study to investigate the incidence, outcomes, risk factors, and microbiological patterns of CRBSI among adult kidney disease patients undergoing hemodialysis at the Philippine General Hospital, the country's largest tertiary referral center. We included all adult patients who received a CVC for hemodialysis from January 1, 2018, to August 31, 2019, and followed them for six months to observe the occurrence of CRBSI and its outcomes.

RESULTS

Our study documented a CRBSI incidence rate of 6.72 episodes per 1000 catheter days, with a relapse rate of 5.08%, a reinfection rate of 15.74%, and a mortality rate of 6.09%. On multivariable regression analysis, we identified autoimmune disease, dialysis frequency of > 3 × per week, use of CVC for either blood transfusion or IV medications, renal hypoperfusion, drug-induced nephropathy, and hypertensive kidney disease as significant risk factors for CRBSI. Gram-negative bacteria, including B. cepacia complex, Enterobacter, and Acinetobacter spp, were the most common organisms causing CRBSI. Multidrug-resistant organisms (MDROs) comprised almost half of the isolates (n = 89, 44.5%), with Coagulase-negative Staphylococcus species having the highest proportion among gram-positive organisms and Acinetobacter spp. among gram-negative isolates.

CONCLUSION

Our findings emphasize the need for more stringent measures and interventions to prevent the propagation of identified pathogens, such as a review of sterile technique and adequate hygiene practices, continued surveillance, and expedited placement and utilization of long-term access for patients on maintenance hemodialysis. Furthermore, CVC use outside of hemodialysis should be discouraged, and common antibiotic regimens such as piperacillin-tazobactam and fluoroquinolones should be reviewed for their low sensitivity patterns among gram-negative isolates. Addressing these issues can improve hemodialysis patients' outcomes and reduce the CRBSI burden in our institution.

Safety and efficacy of very low calorie diet in patients receiving haemodialysis therapy

Background

Very low calorie diets (VLCDs) are an obesity treatment option in the general population, but their efficacy and safety in patients on haemodialysis (HD) is unknown.

Methods

Prospective single arm study of VLCD in haemodialysis patients. All participants received 2.5-3.3 MJ/day for 12 weeks. Weekly assessment of VLCD, pre- and post-dialysis weight, inter-dialytic weight gain, and blood electrolytes occurred for the first 4 weeks, then fortnightly for another 8 weeks. Linear mixed models compared the change in weight over time as well as biochemical outcomes including potassium.

Results

Twenty-two participants [nine home HD (HHD) and 13 satellite HD (SHD)] enrolled with 19 completing the 12-week intervention. Mean post-dialysis weight declined from 121.1 kg at baseline to 109.9 at week 12 resulting in average decline of 0.88 kg per week (95% C.I. 0.71, 1.05, P < .001) with 12-week mean percentage weight loss9.3% (SD 3.5). Mean post-dialysis body mass index declined from 40.9 kg/m2 at baseline to 37.1 kg/m2 at week 12 (95% C.I. 0.25, 0.35, P < .001). Serum potassium rose from week 1 to 3, stabilized during weeks 4 to 6, and fell from week 8, returning near baseline by week 12. Six of the nine (66.6%) HHD participants and seven of the 13 (70%) SHD participants had at least one episode of hyperkalaemia (K > 6 mmol/l). There were no clinical changes in serum sodium, corrected calcium, or phosphate levels during the study.

Conclusion

VLCD with dietitian supervision was effective in producing significant weight reduction, with an acceptable safety profile in patients treated with haemodialysis.

Creatinine, cystatin C, muscle mass, and mortality: Findings from a primary and replication population-based cohort

BACKGROUND

Serum creatinine is used as initial test to derive eGFR and confirmatory testing with serum cystatin C is recommended when creatinine-based eGFR is considered less accurate due to deviant muscle mass. Low muscle mass is associated with increased risk of premature mortality. However, the associations of serum creatinine and cystatin C with muscle mass and mortality remain unclear and require further investigation to better inform clinical decision-making.

METHODS

We included 8437 community-dwelling adults enrolled in the Dutch PREVEND study and 5033 in the US NHANES replication cohort. Associations of serum creatinine and/or cystatin C with muscle mass surrogates and mortality were quantified with linear and Cox proportional hazards regression, respectively. Missing observations in covariates were multiply imputed using Substantive Model Compatible Fully Conditional Specification.

RESULTS

Mean (SD) age of PREVEND and NHANES participants (50% and 48% male) were 49.8 (12.6) and 48.7 (18.7) years, respectively. Median (Q1-Q3) serum creatinine and cystatin C were 71 (61-80) and 80 (62-88) μmol/L and 0.87 (0.78-0.98) and 0.91 (0.80-1.10) mg/L, respectively. Higher serum creatinine was associated with greater muscle mass, while serum cystatin C was not associated with muscle mass. Adjusting both markers for each other strengthened the positive relationship between serum creatinine and muscle mass and revealed an inverse association between serum cystatin C and muscle mass. In the PREVEND cohort, 1636 (19%) deaths were registered over a median follow-up of 12.9 (5.8-16.3) years with a 10-year mortality rate (95% CI) of 7.6% (7.1-8.2%). In the NHANES, 1273 (25%) deaths were registered over a median follow-up of 17.9 (17.3-18.5) years with a 10-year mortality rate of 13.8% (12.8-14.7%). Both markers were associated with increased mortality. Notably, when adjusted for each other, higher serum creatinine was associated with decreased mortality, while the association between serum cystatin C and increased mortality strengthened. The shapes of the associations in the PREVEND study and NHANES were almost identical.

CONCLUSIONS

The strong association between serum creatinine and muscle mass challenges its reliability as GFR marker, necessitating a more cautious approach in its clinical use. The minimal association between serum cystatin C and muscle mass supports its increased use as a more reliable alternative in routine clinical practice.

Positive impact of obesity on the prognosis of liver cirrhosis

BACKGROUND AND AIM

The study aims to determine the prognostic impact of obesity, sarcopenic obesity, and dynapenic obesity in patients with chronic liver disease.

METHODS

This retrospective observational study enrolled patients with chronic hepatitis (n = 746) and liver cirrhosis (n = 434) without hepatocellular carcinoma at entry. The patients were evaluated for sarcopenia and obesity between April 2016 and April 2022. Obesity was defined as a body mass index of ≥ 25 kg/m2. Sarcopenic obesity was defined as low skeletal muscle mass (pre-sarcopenia) with obesity and dynapenic obesity was defined as low muscle strength (dynapenia) with obesity. The effects of obesity on survival were evaluated retrospectively.

RESULTS

The mean observation period was 2.5 years. Obesity, sarcopenic obesity, and dynapenic obesity were found in 271 (45.5%), 17 (2.9%), and 21 (3.5%) men, and 261 (44.7%), 59 (10.1%), and 53 (9.1%) women, respectively. A multivariate Cox proportional hazards model revealed that Child-Pugh class, dynapenia (hazard ratio [HR] 3.89), elderly (≥ 65 years old) (HR 2.11), and obesity (HR 0.58) were independently associated with overall survival (OS). However, neither sarcopenic nor dynapenic obesity were associated with OS. In patients with cirrhosis, the OS of the obese group was significantly higher than that of the non-obese group. The effect of obesity on OS was significant in elderly patients, but not in younger patients.

CONCLUSIONS

Sarcopenic and dynapenic obesity seem unrelated to the prognosis of patients with chronic liver disease. Obesity has a positive effect on the prognosis of elderly patients with cirrhosis.

Nutritional status and its relationship with COVID-19 prognosis in hemodialysis patients

Introduction

Introduction: among the groups more affected by the COVID-19 pandemic were patients undergoing chronic hemodialysis (HD) treatment due to their comorbidities, advanced age, impaired innate and adaptive immune function, and increased nutritional risk due to their underlying inflammatory state. All of these factors contribute to a higher risk of severe complications and worse outcomes compared to the general population when infected with SARS-CoV-2. Objective: the objective of this study was to describe the nutritional characteristics of and their potential association with the prognosis of COVID-19 in patients undergoing chronic HD treatment. Method: a descriptive, retrospective, observational design. All cases of COVID-19 in patients undergoing chronic treatment at the Hemodialysis Unit of Hospital de Manises, Valencia, Spain, from the start of the pandemic to before vaccination were included. Results: for that, 189 patients were studied, who received chronic HD treatment in the hospital unit, 22 patients were diagnosed with COVID-19 (12 %) in that period. The mean age was 71 years, 10 were women, the Charlson index was 6.59 points, diabetes mellitus 10, vintage HD 51.6 months, 2 patients had previously received a currently non-functioning kidney transplant, 16 had arteriovenous fistula as vascular access, and 6 had central vascular access. The mean dialysis session time was 220.14 minutes and the initial value of the single dose of the Kt/V pool was 1.7. 16 patients had body composition measurement, a strong association (p < 0.05) was identified between mortality and BMI, as well as mortality and FTI. Furthermore, the differences between deceased and surviving groups in the serum levels of various variables related to nutritional status were analyzed, finding significant differences with p < 0.05 in the value of triglycerides and ferritin. Conclusions: higher body mass index and higher body fat content, along with lower baseline levels of triglycerides and ferritin, were significantly associated with higher COVID-19 mortality in patients on chronic hemodialysis. These findings suggest that the initial nutritional status of these patients can significantly influence the prognosis of SARS-CoV-2 infection.

Obese patients with atrial fibrillation are more efficiently protected from thrombosis under warfarin or xabans compared to non-obese patients; a systematic review and Meta-analysis of six randomized controlled trials

INTRODUCTION

Recommendations about proper anticoagulation in obese patients, body mass index (BMI) > 30 kg/m2, are not yet clearly defined. Obese patients were included in randomized controlled trials comparing new anticoagulants (NOACs) with warfarin in patients with atrial fibrillation or thromboembolism.

METHODS

We performed a medline search entering proper criteria and finally 6 post-hoc analysis of RCTs, reporting outcome according to BMI, were included in this meta-analysis. Two major outcomes were considered end points in our meta-analysis; thrombosis, including ischemic cerebral events (transient or not) and venous thrombosis (DVD) /pulmonary embolism (PE) and bleeding, including major bleeding and clinically relevant non-major bleeding.

RESULTS

In the NOACs treated group, thrombosis occurred less frequently in obese vs non-obese patients; RR and 95 % CI 0,75 (0,58-0,97), p = 0,03, while low heterogeneity was observed (I2= 40 %). In the warfarin treated subgroup there was statistically significant difference with less thrombotic events occurring in the obese vs non-obese patients; RR and (95 % CI) 0,80 (0,66-0,98), p = 0,03, and heterogeneity was low (I2 = 24 %). This protective effect called the obesity paradox is limited to obese patients anticoagulated for non-valvular atrial fibrillation (NVAF); RR (95 % CI) was 0,70 (0,58-0,85) p = 0,03 and I2 = 24 %. Bleeding events were similar under both NOACs and warfarin in obese vs non-obese analysis.

CONCLUSIONS

Obese patients anticoagulated for NVAF with either standard dose of xabans or INR guided warfarin are more efficiently protected against thrombosis compared to non-obese patients.

Management of Patients With Kidney Disease Undergoing Bariatric Surgery: A Multidisciplinary Approach

Bariatric surgery is increasingly recognized as a safe and effective treatment for obesity in patients with chronic kidney disease (CKD), including stages 4, 5, and 5D (on dialysis). Among the available surgical methods, sleeve gastrectomy (SG) is the most commonly performed weight loss procedure and is mainly done to facilitate kidney transplantation (KT). However, many KT candidates treated with SG remain on the transplant waiting list for months to years, with some never receiving a transplant. Therefore, appropriate candidates for SG must be selected, and post-SG management should address the unique needs of this population, with a focus on sustaining the metabolic benefits of surgery while minimizing potential side effects related to rapid weight loss which may inadvertently lead to muscle and bone catabolism. Multidisciplinary post-SG care in this population may lead to overall better health on the transplant waiting list, resulting in a higher percentage of post-SG patients ultimately receiving KT. To tailor the effective treatment for these patients, clinicians should acknowledge that patients with CKD stage 4-5D have different nutritional needs and are metabolically and psychosocially distinct from the general bariatric surgery population. Sarcopenia is highly prevalent and may be exacerbated by muscle catabolism following SG if not adequately addressed. Blood pressure, glucose, and bone metabolism are all affected by the CKD stage 4-5D, and therefore require distinct diagnostic and management approaches. Long-standing chronic disease, associated comorbidities, and low adherence to medical therapies require ongoing comprehensive psychosocial assessment and support. This paper aims to review and consolidate the existing literature concerning the intersection of CKD stage 4-5D and the consequences of SG. We also suggest future clinical outcome studies examining novel treatment approaches for this medically complex population.

Data-driven, two-stage machine learning algorithm-based prediction scheme for assessing 1-year and 3-year mortality risk in chronic hemodialysis patients

Life expectancy is likely to be substantially reduced in patients undergoing chronic hemodialysis (CHD). However, machine learning (ML) may predict the risk factors of mortality in patients with CHD by analyzing the serum laboratory data from regular dialysis routine. This study aimed to establish the mortality prediction model of CHD patients by adopting two-stage ML algorithm-based prediction scheme, combined with importance of risk factors identified by different ML methods. This is a retrospective, observational cohort study. We included 800 patients undergoing CHD between December 2006 and December 2012 in Shin-Kong Wu Ho-Su Memorial Hospital. This study analyzed laboratory data including 44 indicators. We used five ML methods, namely, logistic regression (LGR), decision tree (DT), random forest (RF), gradient boosting (GB), and eXtreme gradient boosting (XGB), to develop a two-stage ML algorithm-based prediction scheme and evaluate the important factors that predict CHD mortality. LGR served as a bench method. Regarding the validation and testing datasets from 1- and 3-year mortality prediction model, the RF had better accuracy and area-under-curve results among the five different ML methods. The stepwise RF model, which incorporates the most important factors of CHD mortality risk based on the average rank from DT, RF, GB, and XGB, exhibited superior predictive performance compared to LGR in predicting mortality among CHD patients over both 1-year and 3-year periods. We had developed a two-stage ML algorithm-based prediction scheme by implementing the stepwise RF that demonstrated satisfactory performance in predicting mortality in patients with CHD over 1- and 3-year periods. The findings of this study can offer valuable information to nephrologists, enhancing patient-centered decision-making and increasing awareness about risky laboratory data, particularly for patients with a high short-term mortality risk.

Lean-to-fat tissue ratio as a risk factor for cognitive impairment in patients undergoing maintenance hemodialysis

OBJECTIVE

The relationship between body mass index (BMI) and cognitive impairment (CI) remains controversial, and no research has been done to explore the effect of lean-to-fat (L/F) tissue ratio on the risk of CI in patients undergoing maintenance hemodialysis (MHD) so far. This study aimed to explore the effect of L/F tissue ratio on the risk of incident CI in patients undergoing MHD.

METHODS

In this observational cohort study, 3356 patients were recruited and followed up for a median of 2 years. Global cognitive function was measured using Mini-Mental State Examination score. Lean tissue mass (LTM) and fat tissue mass (FTM) were analyzed using body composition monitor based on bioimpedance spectroscopy (BCM-BIS), and L/F tissue ratio was calculated by LTM divided by FTM. Hazard ratios (HRs) for incident CI were determined by Cox regression.

RESULTS

The median age of the cohort was 55 years, and 68.7% patients were less educated. During the follow-up period, 1249 patients (37.2%) experienced incident CI. Patients with lower L/F tissue ratios had significantly higher risks of CI (HR 1.51, 95% confidence interval 1.24-1.84; p < 0.001) than those with higher L/F tissue ratios. The association between L/F tissue ratio and incident CI persisted in all subgroups stratified by sex, age, education status, especially in older and less educated participants. Both in all our patients and subgroups, BMI and CI occurrence were not independently relevant.

CONCLUSION

The L/F tissue ratio rather than BMI was an independent risk factor of incident cognitive impairment in patients undergoing MHD.

Predictors of Arteriovenous Fistula Maturation among Patients with Severe Obesity

BACKGROUND

There is an increasing prevalence of obesity among patients who develop end-stage renal disease and require dialysis. While referrals for arteriovenous fistulas (AVFs) among patients with class 2-3 obesity (i.e., body mass index [BMI] ≥ 35) are increasing, it is unclear what type of autogenous access is most likely to mature in this patient population. This study was designed to evaluate factors that impact maturation of AVF among patients with class ≥2 obesity.

METHODS

We retrospectively reviewed AVFs created at a single center from 2016 to 2019 for patients who had undergone dialysis within the same healthcare system. Ultrasound studies were used to evaluate factors that defined functional maturation, including diameter, depth, and volume flow rates through the fistula. Logistic regression models were used to evaluate the risk-adjusted association between class ≥2 obesity and functional maturation.

RESULTS

A total of 202 AVFs [radiocephalic (24%), brachiocephalic (43%), and transposed brachiobasilic (33%)] were created during the study period, of which 53 (26%) patients had a BMI >35. Functional maturation was significantly lower among patients with class ≥2 obesity undergoing brachiocephalic (58% obese versus 82% normal-overweight; P = 0.017), but not radiocephalic or brachiobasilic AVFs. This was primarily a result of excessive AVF depth in severely obese patients (9.6 ± 4.0 mm obese versus 6.0 ± 2.7 mm normal-overweight; P < 0.001), whereas there was no significant difference found in average volume flow or AVF diameter between groups. In risk-adjusted models, a BMI ≥35 was associated with a significantly lower likelihood of achieving AVF functional maturation (odds ratio: 0.38; 95% confidence interval: 0.18-0.78; P = 0.009) after controlling for age, sex, socioeconomic status, and fistula type.

CONCLUSIONS

Patients with a BMI >35 are less likely to mature AVFs after creation. This principally affects brachiocephalic AVFs and occurs because of increased fistula depth as opposed to diameter or volume flow parameters. These data can help guide decision-making when planning AVF placement in severely obese patients.

Moderate body lipid accumulation in mice attenuated benzene-induced hematotoxicity via acceleration of benzene metabolism and clearance

Recent population and animal studies have revealed a correlation between fat content and the severity of benzene-induced hematologic toxicity. However, the precise impact of lipid deposition on benzene-induced hematotoxicity and the underlying mechanisms remain unclear. In this study, we established a mouse model with moderate lipid accumulation by subjecting the mice to an 8-week high-fat diet (45% kcal from fat, HFD), followed by 28-day inhalation of benzene at doses of 0, 1, 10, and 100 ppm. The results showed that benzene exposure caused a dose-dependent reduction of peripheral white blood cell (WBC) counts in both diet groups. Notably, this reduction was less pronounced in the HFD-fed mice, suggesting that moderate lipid accumulation mitigates benzene-related hematotoxicity. To investigate the molecular basis for this effect, we performed bioinformatics analysis of high-throughput transcriptome sequencing data, which revealed that moderate lipid deposition alters mouse metabolism and stress tolerance towards xenobiotics. Consistently, the expression of key metabolic enzymes, such as Cyp2e1 and Gsta1, were upregulated in the HFD-fed mice upon benzene exposure. Furthermore, we utilized a real-time exhaled breath detection technique to monitor exhaled benzene metabolites, and the results indicated that moderate lipid deposition enhanced metabolic activation and increased the elimination of benzene metabolites. Collectively, these findings demonstrate that moderate lipid deposition confers reduced susceptibility to benzene-induced hematotoxicity in mice, at least in part, by accelerating benzene metabolism and clearance.

Impact of Abdominal Fat Distribution on Mortality and Its Changes Over Time in Patients Undergoing Hemodialysis: A Prospective Cohort Study

OBJECTIVE

Measures of fat distribution and visceral fat accumulation maintain a direct association with mortality in the general population. However, among patients undergoing hemodialysis (HD), there are few reports of this association. This study aimed to investigate the impact of computed tomography (CT)-measured abdominal fat levels, including the visceral fat area (VFA) and subcutaneous fat area (SFA), on all-cause mortality in patients undergoing HD and investigate whether there are sex-specific particularities regarding the associations between the abovementioned parameters.

METHODS

A total of 258 participants were selected from the population of patients undergoing stable HD. The baseline characteristics were collected by records and interviews. The following variables were assessed at baseline and every year: body mass index, abdominal circumference, VFA, and SFA. Abdominal circumference and body fat distribution were assessed at the level of the umbilicus via CT. All CT scans were performed on a nondialysis day with the subject in a supine position. The primary end point was the 5-year all-cause mortality.

RESULTS

This prospective cohort study revealed that age, cardiothoracic ratio, %VFA (VFA/[VFA + SFA]), and albumin were independent predictors of death via multivariable analyses. Regarding the %VFA, its area under the curve (0.599), which did not suffice to predict mortality, was higher than that of VFA, SFA, and body mass index. Also, the effect was recognized mainly in male patients. The %VFA of patients who survived for 60 months increased over time.

CONCLUSION

These data suggest that patients (especially men) with a high VFA-to-abdominal fat ratio have a high risk of death. Thus, more attention should be paid to such patients.

The prognostic effects of the geriatric nutritional risk index on elderly acute kidney injury patients in intensive care units

Introduction

The geriatric nutritional risk index (GNRI), a nutritional screening tool specifically for the aging population, has been proven to be associated with worse outcomes in chronic kidney disease patients, especially in the hemodialysis population. However, the predictive validity of GNRI in critically ill elderly patients with acute kidney injury (AKI) is yet to be determined. This analysis sought to examine the prognostic effects of GNRI on elderly AKI patients in intensive care units (ICUs).

Methods

We collected elderly AKI patient-relevant data from the Medical Information Mart for Intensive Care III database. AKI was diagnosed and staged according to the "Kidney Disease Improving Global Outcomes" criteria. In the study, 1-year mortality was considered the primary outcome, whereas in-hospital, ICU, 28-day and 90-day mortality, and prolonged length of stay in ICU and hospital were selected as the secondary outcomes.

Results

In all, 3,501 elderly patients with AKI were selected for this study, with a 1-year mortality rate of 36.4%. We classified the study population into low (≤98) and high (>98) GNRI groups based on the best cutoff value. The incidence of endpoints was remarkably lower in patients with elevated GNRI (p < 0.001). When stratified by the AKI stage, patients with high GNRI at AKI stages 1, 2, and 3 had markedly lower 1-year mortality than those with low GNRI (all p < 0.05). The multivariable regression analysis identified the independent prognostic ability of GNRI on the research outcomes (all p < 0.05). Restricted cubic spline exhibited a linear correlation between GNRI and 1-year death (p for non-linearity = 0.434). The prognostic implication of GNRI on 1-year mortality was still significant in patients with the most subgroups.

Conclusion

In critically ill elderly patients with AKI, elevated GNRI upon admission was strongly correlated with a lower risk of unfavorable outcomes.

Cognitive-behavioral and dietary weight loss intervention in adult kidney transplant recipients with overweight and obesity: Results of a pilot RCT study (Adi-KTx)

The obesity epidemic and its health consequences have not spared the population of kidney transplant (KTx) candidates and recipients. In addition, KTx recipients are susceptible to weight gain after transplantation. Overweight and obesity after KTx are strongly associated with adverse outcomes. Therefore, we designed a randomized controlled, mono-center study to specifically test the effectiveness of a primarily cognitive-behavioral approach supplemented by nutritional counseling for weight reduction following KTx as the intervention group (IG) in comparison to a brief self-guided intervention as control group (CG). The study was registered in the German Clinical Trials Register (DRKS-ID: DRKS00017226). Fifty-six KTx patients with a BMI from 27 to 40 kg/m2 were included in this study and randomized to the IG or CG. Main outcome was the number of participants achieving a 5% weight loss during the treatment phase. Additionally, participants were assessed 6 and 12 months after the end of the 6-month treatment phase. Participants significantly lost weight without group differences. 32.0% (n = 8) of the patients in the IG and 16.7% (n = 4) of the patients in the CG achieved a weight loss of 5% or more. Weight loss was largely maintained during follow-up. Retention and acceptance rate in the IG was high, with 25 (out of 28) patients completing all 12 sessions and one patient completing 11 sessions. Short-term, cognitive-behaviorally oriented weight loss treatment seems to be feasible and acceptable for patients after KTx who suffer from overweight or obesity. This clinical trial was ongoing at the onset of the COVID-19 pandemic which might have influenced study conduct and results. Clinical Trial Registration: https://clinicaltrials.gov/ DRKS-ID: DRKS00017226.

Low serum creatinine, a surrogate marker of muscle mass, correlates with insulin sensitivity in nonhuman primates

OBJECTIVES

Decreased serum creatinine levels are associated with increased risk of type 2 diabetes (T2DM) in humans, however, its association with muscle mass and insulin sensitivity have not been studied in NHPs.

METHODS

Retrospective data of 229 adult NHPs were studied for association of serum creatinine levels with muscle mass and onset of T2DM.

RESULTS

Serum creatinine levels were positively correlated with lean muscle mass in nondiabetic (non-DM), male and female NHPs. Aged NHPs had significantly reduced lean muscle mass and corresponding creatinine levels compared to young age groups (p < .001). Creatinine was positively correlated with insulin sensitivity in nonDM male NHPs and significant decrease in creatinine was observed in T2DM (p < .001) compared to same age group nonDM NHPs.

CONCLUSIONS

The pathophysiology of T2DM in NHPs is similar to humans, low creatinine further provides utility of surrogate biomarkers of lower muscle mass and risk factor for T2DM NHPs.

The obesity paradox in patients with acute coronary syndromes over 2 decades - the ACSIS registry 2000-2018

BACKGROUND

Obesity is a worldwide epidemic which is associated with major cardiovascular (CV) risk factors. Nevertheless, substantial distant data, mostly published more than a decade ago, have demonstrated an obesity paradox, where obese patients generally have a better short- and long-term prognosis than do their leaner counterparts with the same CV profile. Nonetheless, it is not fully elucidated whether the obesity paradox is still relevant in the contemporary cardiology era among patients with acute coronary syndrome (ACS). We aimed to examine temporal trends in the clinical outcomes of ACS patients by their BMI status.

METHODS

Data from the ACSIS registry including all patients with calculated BMI data between the years 2002-2018. Patients were stratified by BMI groups to underweight, normal, overweight and obese. Clinical endpoints included 30d major cardiovascular events (MACE), and 1-year mortality. Temporal trends were examined in the late (2010-2018) vs. the early period (2002-2008). Multivariable models examined factors associated with clinical outcomes by BMI status.

RESULTS

Among the 13,816 patients from the ACSIS registry with available BMI data, 104 were underweight, 3921 were normal weight, 6224 were overweight and 3567 were obese. 1-year mortality was highest among underweight patients (24.8%), as compared to normal weight patients (10.7%) and lowest among overweight and obese patients (7.1% and 7.5% respectively; p for trend <0.001). 30-day MACE rates followed a similar pattern (24.3% for underweight, 13.6% for normal weight, 11.6% for overweight, and 11.7% for obese; p for trend<0.001). Comparing the 2 time-periods, 30-day MACE was significantly lower in the late period in all BMI groups, but unchanged in patients who were underweight. Similarly, 1-year mortality has decreased in normal weight and obese patients but remained similarly high in underweight patients.

CONCLUSIONS

In ACS patients, during 2-decades, 30-day MACE and 1-year mortality were lower among overweight and obese patients compared to underweight and even normal weight patients. Temporal trends revealed that 30-day MACE and 1-year mortality have decreased among all BMI groups other than the underweight ACS patients, among whom the adverse CV rates were consistently high. Our findings suggest that the obesity paradox is still relevant in ACS patients in the current cardiology era.

Nutritional Assessment of Adult Patients Undergoing Maintenance Hemodialysis in the Gaza Strip

Malnutrition is a common condition in patients undergoing hemodialysis (HD), and it is associated with increased morbidity and mortality. The main objective of the study was to evaluate the nutritional status of patients on maintenance HD. After applying eligibility criteria, 141 HD patients attending major governmental dialysis centers were randomly recruited in this cross-sectional study and assessed for nutritional status using the Patient-Generated Subjective Global Assessment (PG-SGA) tool. The PG-SGA categorizes patients as well-nourished, moderately malnourished, and severely malnourished. Different anthropometric measurements, laboratory investigations, blood pressure measurements, and 24-h dietary recall were collected from each patient. According to PG- SGA results, 78% of patients were moderately malnourished and 22% of patients were severely malnourished. The mean body mass index was 27.8 kg/m2, and 5.7% of patients were underweight. There were significant differences in the mid-upper arm muscle circumference (P = 0.020) between the PG-SGA groups. The total energy and protein intake were significantly (P <0.001) less than the recommended dietary intake by 1268.9 kcal and 41.4 g, respectively. The albumin level in 37.6% of patients was less than the normal level, and the results indicated that there were significant differences in serum iron (P = 0.022) between the moderately and severely malnourished patients. The results of this study indicated that all HD patients were suffering from different degrees of malnutrition and, unfortunately, most of their energy and nutrient intake was far less than the requirements, which might be the reason why they face nutritional and health risks.

Low BMI and high waist-to-hip ratio are associated with mortality risk among hemodialysis patients: a multicenter prospective cohort study

Background

Data are limited on the relationship between waist-to-hip ratio (WHR) and mortality risk among maintenance hemodialysis (MHD) patients. Moreover, the combined association of body mass index (BMI) and WHR with mortality remains uncertain. Therefore, we aimed to explore the individual and combined association of BMI and WHR with the all-cause and cardiovascular disease (CVD) mortality.

Methods

In this multicenter prospective cohort study, we enrolled 1034 MHD patients. The primary outcome was all-cause mortality and secondary outcome was CVD mortality. Multivariable Cox proportional hazards models were used to evaluate the individual and combined association of BMI and WHR with the risk of mortality.

Results

A nonlinear inverse relationship was found between BMI and risk of all-cause mortality (P for nonlinearity <.05). Being underweight (<18.5 kg/m2) was associated with higher all-cause mortality risk (HR 1.45; 95% CI 1.08-1.94) compared with normal weight (18.5-23.9 kg/m2), while being overweight (24-27.9 kg/m2; HR 0.96; 95% CI 0.70-1.31) and obese (≥28 kg/m2; HR 1.19; 95% CI 0.62-2.26) showed no significant differences. Of note, WHR was independently and positively associated with all-cause mortality (per standard deviation increase, HR 1.13; 95% CI 1.00-1.27). When analyzed jointly, patients with low BMI (<18.5 kg/m2) and high WHR (≥0.95) had the highest risk of all-cause mortality. Similar results were obtained for CVD mortality.

Conclusions

In patients undergoing hemodialysis from China, low BMI and high WHR were individually and jointly associated with higher risk of mortality. Our results emphasize that BMI and WHR may jointly affect the prognosis of MHD patients.

Trends, Social Context, and Transplant Implications of Obesity Among Incident Dialysis Patients in the United States

BACKGROUND

Kidney transplant programs have variable thresholds to accept obese candidates. This study aimed to examine trends and the social context of obesity among United States dialysis patients and implications for kidney transplant access.

METHODS

We performed a retrospective cohort study of 1 084 816 adults who initiated dialysis between January 2007 and December 2016 using the United States Renal Data System data. We estimated national body mass index (BMI) trends and 1-y cumulative incidence of waitlisting and death without waitlisting by BMI category (<18.5 kg/m 2 , ≥18.5 and <25 kg/m 2 [normal weight], ≥25 and <30 kg/m 2 [overweight], ≥30 and <35 kg/m 2 [class 1 obesity], ≥35 and <40 kg/m 2 [class 2 obesity], and ≥40 kg/m 2 [class 3 obesity]). We then used Fine-Gray subdistribution hazard regression models to examine associations between BMI category and 1-y waitlisting with death as a competing risk and tested for effect modification by End Stage Renal Disease (ESRD) network, patient characteristics, and neighborhood social deprivation index.

RESULTS

The median age was 65 (interquartile range 54-75) y, 43% were female, and 27% were non-Hispanic Black. From 2007 to 2016, the adjusted prevalence of class 1 obesity or higher increased from 31.9% to 38.2%. Class 2 and 3 obesity but not class 1 obesity were associated with lower waitlisting rates relative to normal BMI, especially for younger individuals, women, those of Asian race, or those living in less disadvantaged neighborhoods ( pinteraction < 0.001 for all).

CONCLUSIONS

Obesity prevalence is rising among US incident dialysis patients. Relative to normal BMI, waitlisting rates with class 2 and 3 obesity were lower and varied substantially by region, patient characteristics, and socioeconomic context.

Prevalence of Protein-Energy Wasting in Dialysis Patients Using a Practical Online Tool to Compare with Other Nutritional Scores: Results of the Nutrendial Study

This cross-sectional study aims to explore the prevalence of protein-energy wasting (PEW) in dialysis patients in Catalonia, Spain, using a new and practical online tool which enables rapid calculation and comparison with other nutritional scores. Methods: A web tool (Nutrendial) was created to introduce different variables and automatically calculate PEW, Malnutrition inflammation Score (MIS) and Subjective Global Assessment (SGA) in 1389 patients (88% in haemodialysis (HD)), 12% in peritoneal dialysis (PD) from different regions of Catalonia. Results: A prevalence of 23.3% (26% HD, 10.2% PD) of PEW was found, with a mean MIS score of 6 and SGA score of C in 7% of the patients. ROC analysis showed MIS as the best nutritional score to diagnose PEW (AUC 0.85). Albumin delivered lower diagnostic precision (AUC 0.77) and sensitivity (66%). A cut off point of 7 (86% sensitivity and 75% specificity) for MIS and 3.7 mg/dL for albumin were found to predict the appearance of PEW in this population. SGA B or C showed an 87% sensitivity and 55% specificity to diagnose PEW. Very low nutritional intervention (14%) was recorded with this tool in patients with PEW. Conclusions: This new online tool facilitated the calculation of PEW, enabling different professionals—including nephrologists, dieticians and nurses—to efficiently obtain insights into the nutritional status of the Catalonian dialysis population and implement the required nutritional interventions. MIS is the score with more sensitivity to diagnose PEW.

Hypothesis: Enhanced glucose availability and insulin resistance enhances an activated immune system and accounts for the obesity paradox

Many studies have demonstrated an 'obesity paradox' where people with obesity have reduced mortality in the context of acute critical illnesses compared to people of normal weight. In contrast, obesity is associated with reduced life expectancy in the population in general and is associated with an increased risk for type 2 diabetes, cardiovascular disease and other health problems. However, the absence of the metabolic syndrome is associated a lower mortality than when the metabolic syndrome is present regardless of body mass index status and the obesity paradox appears to only occur in association with the metabolic syndrome, but cardiorespiratory fitness modifies these outcomes. Enhanced glucose availability is important when the immune system is activated not only because it has an acute onset, a high consumption of glucose and is substantially an obligate glucose utilizer but also because it has priority over most other tissues and cells for the available glucose. Thus, for vulnerable populations, such as children with severe infections, this increases the risk of hypoglycaemia and death. The obesity paradox may be substantially a consequence of two features associated with obesity. One is endogenous glucose production (EGP). Obesity is associated with an increased capacity for EGP and thus is associated with enhanced glucose availability. Second is insulin resistance that reduces the amount of glucose metabolized by cells that are not obligate glucose utilizers and increases the release of fatty acids and glycerol from adipose stores that are alternative fuels for tissues and cells.

Colorectal resection in end-stage renal disease (ESRD) patients: experience from a single tertiary center

BACKGROUND

End-stage renal disease (ESRD) and renal replacement therapy (RRT) are important risk factors for post-operative morbidity and mortality but remains poorly reported in colorectal surgery. This study aims to evaluate postoperative outcomes of ESRD patients under RRT undergoing colorectal resection.

METHODS

All ESRD patients under RRT who underwent colorectal resection between 2006 and 2019 were retrospectively reviewed. Perioperative outcomes were analysed, such as risk factors of postoperative complications.

RESULTS

Forty-two patients were analysed, including 27 emergency and 15 elective surgeries. The most frequent indication was acute colonic ischemia for emergency and malignancy for elective procedures. Laparoscopic approach was used in 12 patients (29%), without difference between elective and emergency groups. Postoperative severe complications rate (including deaths) was 50% (21/42), including 56% (15/27) and 40% (6/15) in emergency and elective groups, respectively (p = .334). Anastomotic leak was observed in 3 of the 23 patients (13%) undergoing digestive anastomosis, (1 in emergency and 2 in elective groups, p = .246). The postoperative mortality rate was 29%, not significantly different between groups. The median hospital stay was 14.5 days (8-42). At univariate analysis, history of cardiac event (p = .028) and open approach (p = .040) were associated with severe complications, and ASA score >3 (p = .043), history of cardiac event (p = .001) and diabetes (p = .030) associated with mortality.

CONCLUSIONS

Colorectal surgery in ESRD patient exposes to high risk of morbidity and mortality, even in the elective setting, especially in patients with comorbidities like cardiac event and diabetes. Careful patient selection and closed management is required in such fragile patients.

Long-term weight loss as a predictor of mortality in haemodialysis patients

BACKGROUND

Serial weight decrease can be a prognostic predictor in chronic haemodialysis (HD) patients. We investigated the impact of long-term post-HD body weight (BW) changes on all-cause mortality among HD patients.

METHODS

This longitudinal cohort study and post-hoc analysis evaluated participants of a previous randomised controlled trial conducted between 2006 and 2011 who were followed up until 2018. Weight change slopes were generated with repeated measurements every 6 months during the trial for patients having ≥5 BW measurements. Participants were categorised into four groups based on quartiles of weight change slopes; the median weight changes per 6 months were -1.02 kg, -0.25 kg, +0.26 kg, and +0.86 kg. Cox proportional hazard regression was used to evaluate differences in subsequent survival among the four groups. BW trajectories were plotted with a backward time-scale and multilevel regression analysis to visualise the difference in BW trajectories between survivors and non-survivors.

RESULTS

Among the 461 patients, 404 were evaluated, and 168 (41.6%) died within a median follow-up period of 10.2 years. The Cox proportional hazard regression adjusted for covariates and baseline BW showed that a higher rate of weight loss was associated with higher mortality. The hazard ratios were 2.02 (1.28-3.20), 1.77 (1.10-2.85), 1.00 (reference), and 1.11 (0.67-1.83) for the first, second, third (reference), and fourth quartiles, respectively. BW trajectories revealed a significant decrease in BW in non-survivors.

CONCLUSIONS

Weight loss elucidated by serial BW measurements every 6 months is significantly associated with higher mortality among HD patients.

The weight of words: Discursive constructions of health in weight-neutral peer-reviewed journal articles

Weight-neutral approaches to health, like the Health at Every Size® (HAES®) approach arose in response to emerging evidence showing the negative health consequences of weight-focused approaches through the effects of stigma and marginalization in many settings, including healthcare. While the discourses of dominant 'weight-normative' approaches are well-researched and described, little is known about how language and discourse is creating certain 'truths' about weight-neutral approaches. The aim of this study was to explore how academic discourses create truths about weight-neutral approaches to health. A discourse analysis of 63 academic journal articles was conducted. We found that the language used in academic literature is creating confusing and contradictory messages about weight and weight-neutral approaches to health (like the HAES® approach) through: (i) the continued use of stigmatising and normative labels like 'overweight' and 'obese', (ii) paradoxical language like 'flexible restraint', and (iii) a focus on individual responsibility and blame for health and weight without acknowledgement of broader societal and systemic factors. More research is needed to characterize weight-neutral approaches and develop a clearer framework for researchers wishing to engage with the weight-neutral paradigm of health.

Longitudinal Assessment of Body Composition and Its Association With Survival Among Participants of the ACTIVE/ADIPOSE Study

OBJECTIVES

The importance of muscle wasting as a predictor of mortality in the hemodialysis population is not clear. Lack of association of muscle mass with survival in some studies could be related to reliance on single measures or to incorporation of excess extracellular water (ECW) into estimates of muscle mass. We examined changes in body composition over a 2-year period and the association of body composition with survival.

DESIGN AND METHODS

We analyzed data from 325 adults receiving hemodialysis in the Bay Area. We estimated ECW, intracellular water (ICW), and fat mass by whole-body bioimpedance spectroscopy (BIS) at 0, 12, and 24 months from enrollment. We used linear mixed modeling to examine changes in body mass index and BIS-derived estimates of body composition and Cox modeling with BIS-derived estimates as time-varying independent variables to examine associations between body composition and survival in multivariable analyses.

RESULTS

Body mass index declined over time. Considering individual components of body composition, ICW declined (-0.09 kg/m² per year, 95% confidence interval -0.14 to -0.04), but fat mass and ECW did not change significantly. There were 120 deaths over a median of 5.2 years. The relationship between ICW and mortality was not linear such that the association was steeper at low values of ICW, whereas higher ICW was associated with better survival that was relatively stable above 9 kg/m2. Higher ECW was associated with higher mortality, and fat mass was not associated with survival. These associations were independent of markers of inflammation and nutritional status.

CONCLUSIONS

ICW declined over 2 years in this cohort, whereas fat mass and ECW remained relatively stable. Higher ICW was associated with better survival, but higher fat mass was not. Higher ECW was associated with worse survival. These results suggest that muscle mass may predict survival among patients on hemodialysis.

Effect of Pretransplant Body Mass Index on Kidney Transplant Recipient and Graft Long-term Survival

BACKGROUND

The aim of the study was to assess the influence of pretransplant body mass index (BMI [calculated as weight in kilograms divided by height in meters squared]) to the graft and patient 5- and 10-year survival.

METHODS

Our study group consisted of 706 patients who received their kidney transplant after the year 2000.

RESULTS

Almost half, 51.9% (n = 372) of the patients had BMI < 25, and 47.6% (n = 336) had BMI ≥ 25. Patients who were overweight or obese were significantly older than other groups (P = .01). The 5-year recipient survival was significantly better in the BMI < 25 group (n = 291, 79.5%) than the BMI ≥ 25 group (n = 238, 70.2%, P < .05). In addition, 10-year recipient survival was better in the BMI < 25 group (n = 175, 47.8%) compared with the BMI ≥ 25 group (n = 127, 37.5%, P < .05). Similarly, 5-year graft survival was better in the BMI < 25 group (66.9%, n = 242) compared with the BMI ≥ 25 group (61.1%, n = 204, P < .05). However, 10-year graft survival was not statistically significant (P = .08). Regarding the impact of diabetes on survival, we found patients with diabetes mellitus to have worse survival in all groups (P = .009).

CONCLUSIONS

Recipient graft survival was affected by diabetes mellitus independently from being overweight. In the current study, we demonstrated that pretransplant obesity or being overweight affects recipient and graft short-term survival, but long-term comparison of patients who were overweight or obese with patients with normal BMI revealed minimal recipient survival differences and in graft survival analysis no difference. Although in many studies obesity and being overweight predict a bad outcome for kidney transplant recipient survival, our research did not fully confirm it. Diabetes mellitus had worse outcome in all patients groups.

Bariatric surgery prior to transplantation and risk of early hospital re-admission, graft failure, or death following kidney transplantation

Bariatric surgery has been shown to be safe in the dialysis population. Whether bariatric surgery before kidney transplantation influences posttransplant outcomes has not been examined nationally. We included severely obese (BMI >35) dialysis patients between 18 and 70 years who received a kidney transplant according to the US Renal Data System. We determined the association between history of bariatric surgery and risk of 30-day readmission, graft failure, or death after transplantation using multivariable logistic, Fine-Gray, and Cox models. We included 12 573 patients, of whom 503 (4%) received bariatric surgery before transplantation. Median age at transplant was 53 years; 42% were women. Overall, history of bariatric surgery was not statistically significantly associated with graft failure (HR 1.02; 95% CI 0.77-1.35) or death (HR 1.10; 95% CI 0.84-1.45). However, sleeve gastrectomy (vs. no bariatric surgery) was associated with lower risk of graft failure (HR 0.39; 95% CI 0.16-0.95). In conclusion, history of bariatric surgery prior to kidney transplantation was not associated with allograft or patient survival, but findings varied by surgery type. Sleeve gastrectomy was associated with better graft survival and should be considered in severely obese transplant candidates receiving dialysis.

Sex Differences in Cancer Genomes: Much Learned, More Unknown

Cancer is a leading cause of death worldwide. Sex influences cancer in a bewildering variety of ways. In some cancer types, it affects prevalence; in others, genomic profiles, response to treatment, or mortality. In some, sex seems to have little or no influence. How and when sex influences cancer initiation and progression remain a critical gap in our understanding of cancer, with direct relevance to precision medicine. Here, we note several factors that complicate our understanding of sex differences: representativeness of large cohorts, confounding with features such as ancestry, age, obesity, and variability in clinical presentation. We summarize the key resources available to study molecular sex differences and suggest some likely directions for improving our understanding of how patient sex influences cancer behavior.

Obesity Management in Kidney Transplant Candidates: Current Paradigms and Gaps in Knowledge

In this review, we discuss the increasing prevalence of obesity among people with chronic and end-stage kidney disease (ESKD) and implications for kidney transplant (KT) candidate selection and management. Although people with obesity and ESKD receive survival and quality-of-life benefits from KT, most KT programs maintain strict body mass index (BMI) cutoffs to determine transplant eligibility. However, BMI does not distinguish between visceral adiposity, which confers higher cardiovascular risks and risks of perioperative and adverse posttransplant outcomes, and muscle mass, which is protective in ESKD. Furthermore, requirements for patients with obesity to lose weight before KT should be balanced with the findings of numerous studies that show weight loss is a risk factor for death among patients with ESKD, independent of starting BMI. Data suggest that KT is associated with survival benefits relative to remaining on dialysis for candidates with obesity although recipients without obesity have higher delayed graft function rates and longer transplant hospitalization durations. Research is needed to determine the optimal body composition metrics for KT candidacy assessments and risk stratification. In addition, ESKD-specific obesity management guidelines are needed that will address the neurologic, behavioral, socioeconomic, and physical underpinnings of this increasingly common disease.

The Uniqueness of Clear Cell Renal Cell Carcinoma: Summary of the Process and Abnormality of Glucose Metabolism and Lipid Metabolism in ccRCC

Kidney cancer is a cancer with an increasing incidence in recent years. Clear cell renal cell carcinoma (ccRCC) accounts for up to 80% of all kidney cancers. The understanding of the pathogenesis, tumor progression, and metastasis of renal carcinoma is not yet perfect. Kidney cancer has some characteristics that distinguish it from other cancers, and the metabolic aspect is the most obvious. The specificity of glucose and lipid metabolism in kidney cancer cells has also led to its being studied as a metabolic disease. As the most common type of kidney cancer, ccRCC has many characteristics that represent the specificity of kidney cancer. There are features that we are very concerned about, including the presence of lipid droplets in cells and the obesity paradox. These two points are closely related to glucose metabolism and lipid metabolism. Therefore, we hope to explore whether metabolic changes affect the occurrence and development of kidney cancer by looking for evidence of changes on expression at the genomic and protein levels in glucose metabolism and lipid metabolism in ccRCC. We begin with the representative phenomenon of abnormal cancer metabolism: the Warburg effect, through the collection of popular metabolic pathways and related genes in the last decade, as well as some research hotspots, including the role of ferroptosis and glutamine in cancer, systematically elaborated the factors affecting the incidence and metastasis of kidney cancer. This review also identifies the similarities and differences between kidney cancer and other cancers in order to lay a theoretical foundation and provide a valid hypothesis for future research.

Clinical assessment of nutritional status using the modified quantified subjective global assessment and anthropometric and biochemical parameters in patients undergoing hemodialysis in Macao

OBJECTIVE

Malnutrition is widespread among patients undergoing hemodialysis and is linked to high morbidity and mortality rates. We evaluated the nutritional status and malnutrition markers in patients undergoing hemodialysis in Macao.

METHODS

We performed a cross-sectional analysis of 360 patients in a hemodialysis center. The modified quantitative subjective global assessment (MQSGA), anthropometric indices and related biochemical test data were used to evaluate nutritional status.

RESULTS

The sample's mean age was 63.47 ± 13.95 years. There were 210 well-nourished (58.3%), 139 mild-to-moderately malnourished (38.6%) and 11 severely malnourished (3.1%) patients. Older patients had a higher incidence of severe malnutrition, but there were no significant differences between diabetic and non-diabetic patients. Mid-arm circumference (MAC); mid-arm muscle circumference; body mass index; triceps skin fold thickness; serum albumin, creatinine and urea; and hemoglobin were all valid for assessing nutritional status. MAC and the serum albumin and creatinine concentrations significantly negatively correlated with MQSGA.

CONCLUSIONS

Malnutrition is commonplace in patients undergoing hemodialysis in Macao, but their nutritional status is not affected by diabetes. Serum creatinine, serum albumin and MAC, and especially pre-dialysis creatinine concentration, represent effective, readily available, and easily remembered screening measures of nutritional status for patients undergoing maintenance dialysis.

Obesity paradox and heart failure

BACKGROUND

There is scientific consensus that obesity increases the risk of cardiovascular diseases (CVD), including heart failure (HF). However, in CVD, many studies observed greater survival in overweight or class 1 obesity individuals. This counterintuitive observation was termed "obesity paradox" (OP).

OBJECTIVE AND METHODS

This article is a narrative overview of the relationship between OP and CVD, particularly HF. The sources used were MEDLINE/PubMed, CINAHL, EMBASE, and Cochrane Library, from 2001 to 31 May 2020, exception for a 1983 work of historical importance. Studies reporting association and prognostic impact of obesity in HF and the impact of body composition on cardiac structure and myocardial function in obesity were also included in this review. In addition, we examined references from the retrieved articles and explored several related websites. Ultimately, we chose 79 relevant documents. Fifty-three were specifically focused on OP and HF.

RESULTS

In this review, we made a summary of the evidence coming from a series of studies investigating OP. Many of these studies do not take into consideration or underestimate some of the more important morpho-functional variables of patients suffering from HF: among these, body composition and visceral adiposity, sarcopenic obesity, muscle fitness (MF), and cardiorespiratory fitness (CRF). A high body mass index (BMI) represents a risk factor for HF, but it also seems to exert a protective effect under certain circumstances. Fat distribution, lean mass, and cardio fitness could play an essential role in determining the observed differences in the HF population.

CONCLUSION

BMI does not distinguish between the metabolically healthy and metabolically unhealthy obesity. The obesity impact on morbidity and premature mortality can be underestimated and, therefore, may lead to incorrect clinical courses.

LEVEL OF EVIDENCE

Level V, Narrative review.

Are we overfeeding hemodialysis patients with protein? Exploring an alternative method to estimate protein needs

BACKGROUND & AIMS

Sufficient protein intake is of great importance in hemodialysis (HD) patients, especially for maintaining muscle mass. Daily protein needs are generally estimated using bodyweight (BW), in which individual differences in body composition are not accounted for. As body protein mass is best represented by fat free mass (FFM), there is a rationale to apply FFM instead of BW. The agreement between both estimations is unclear. Therefore, the aim of this study is to compare protein needs based on either FFM or BW in HD patients.

METHODS

Protein needs were estimated in 115 HD patients by three different equations; FFM, BW and BW adjusted for low or high BMI. FFM was measured by multi-frequency bioelectrical impedance spectroscopy and considered the reference method. Estimations of FFM x 1.5 g/kg and FFM x 1.9 g/kg were compared with (adjusted)BW x 1.2 and x 1.5, respectively. Differences were assessed with repeated measures ANOVA and Bland-Altman plots.

RESULTS

Mean protein needs estimated by (adjusted)BW were higher compared to those based on FFM, across all BMI categories (P < 0.01) and most explicitly in obese patients. In females with BMI >30, protein needs were 69 ± 17.4 g/day higher based on BW and 45 ± 9.3 g/day higher based on BMI adjusted BW, compared to FFM. In males with BMI >30, protein needs were 51 ± 20.4 g/day and 23 ± 20.9 g/day higher compared to FFM, respectively.

CONCLUSIONS

Our data show large differences and possible overestimations of protein needs when comparing BW to FFM. We emphasize the importance of more research and discussion on this topic.

Agreement of Single-Frequency Electrical Bioimpedance in the Evaluation of Fat Free Mass and Fat Mass in Peritoneal Dialysis Patients

Background: Protein-energy wasting is related to impairment of quality of life and lower survival of end-stage kidney disease (ESKD) patients. The evaluation of body composition, especially fat free mass (FFM) and fat mass (FM), is important for the prediction of outcomes in these individuals. The aim of this study was to compare the FFM and FM measurements obtained by single-frequency bioimpedance (SF-BIA) and by a multiple frequency bioimpedance (MF-BIA) device, using dual energy X-ray absorptiometry (DXA) peritoneal dialysis (PD) patients. Methods: This was a cross-sectional study involving adult patients undergoing regular PD, in which we performed SF-BIA, MF-BIA, and DXA at the same visit. To compare the bioimpedance values with DXA, we used: Person correlation (r), intraclass correlation coefficient (ICC), and Bland-Altman concordance analysis. Results: The sample consisted of 50 patients in the PD, with mean age of 55.1 ± 16.3 years. Both bioimpedance methods showed a strong correlation (r > 0.7) and excellent reproducibility (ICC > 0.75) compared to DXA. According to the Bland-Altman diagram, SF-BIA showed agreement in body compartment measurements, with no proportionality bias (p > 0.05), without systematic bias for FFM (-0.5 ± 4.9, 95% CI -1.8 to 0.9, p = 0.506), and for FM (0.3 ± 4.6, p = 0.543). MF-BIA did not present a proportionality bias for the FFM, but it underestimated this body compartment by 2.5 ± 5.4 kg (p = 0.002). In addition, MF-BIA presented proportionality bias for FM. Conclusion: SF-BIA was a more accurate assessing method than MBIA for FFM and FM measurements in PD patients. Because it is a low-cost, non-evaluator-dependent measurement and has less systematic bias, it can also be recommended for fat mass and free-fat mass evaluation in PD patients.

Malnutrition score and Body Mass Index as nutritional screening tools for hemodialysis patients

BACKGROUND AND AIMS

Malnutrition is highly prevalent in the hemodialysis population. Nutritional screening is important to identify patients at risk of malnutrition. This study aimed to investigate the concurrent validity of BMI cut-offs (BMI < 23 kg/m² and BMI < 18.5 kg/m²) and DMS, as simple nutritional screening tools, compared to PG-SGA, as the reference standard, in detecting the risk of malnutrition in hemodialysis patients.

DESIGN

A Single-centered cross-sectional study design.

METHODS

A total of 98 patients on maintenance hemodialysis, who were at least 18 years old (mean age: 51.33 ± 14.12) and subjected to hemodialysis for at least 3 months, were screened. Concurrent validity was assessed using receiver operating characteristic (ROC) curve analysis as well as sensitivity, specificity, accuracy, PPV, NPV, LR⁺ and LR^-, against diagnosed malnutrition.

RESULTS

The patients considered malnourished were 71.4% (n = 70), with the majority being females (60%), and possessed a BMI distribution of 28.2 ± 6.3 kg/m². DMS (score ≥ 14) agreed with diagnosed malnutrition (κ = 0.450 (95% CI 0.26-0.64) <0.0005). Furthermore, DMS (score ≥ 14) showed a sensitivity and a specificity of 84.3% and 60.7%, respectively. However, BMI cut-offs (<23 kg/m² or < 18.5 kg/m²) did not show any agreement with diagnosed malnutrition.

CONCLUSION

DMS is a useful screening tool for detecting the risk of malnutrition in hemodialysis patients. On the contrary, BMI <23 kg/m² and BMI <18.5 kg/m² were not valid tools for identifying the risk of malnutrition in hemodialysis patients.

Association between geriatric nutritional risk index and stroke risk in hemodialysis patients: 10-Years outcome of the Q-Cohort study

BACKGROUNDS AND AIMS

The geriatric nutritional risk index (GNRI), which is calculated using the serum albumin level and body mass index, is a nutritional marker associated with an increased risk of cardiovascular events in patients who are receiving hemodialysis. However, no studies have examined the association between the GNRI level and the incidence of stroke in this population.

METHODS

Three thousand forty-five patients were registered in the Q-Cohort Study, which is a multicenter, observational cohort of hemodialysis patients. The main outcomes were brain infarction and brain hemorrhage. The main exposure was GNRI levels at baseline. Patients were divided into quartiles on the basis of baseline GNRI levels: Q1, <90.7; Q2, 90.7-95.5; Q3, 95.6-99.8; Q4, >99.8. The risk of brain infarction or hemorrhage was estimated using the multivariable-adjusted Cox proportional hazard risk models and restricted cubic spline analyses.

RESULTS

During the 10-year follow-up period, 326 patients developed brain infarction and 149 patients developed brain hemorrhage. Cox proportional hazard risk models showed that the risk of brain infarction and hemorrhage in Q1 was significantly higher than that in Q4 group. The hazard ratios [95% confidence intervals] were 1.49 [1.05-2.12] and 1.89 [1.11-3.20], respectively. Restricted cubic spline curves showed that a lower GNRI was incrementally associated with an increased risk for both brain infarction and brain hemorrhage.

CONCLUSIONS

Our results suggest that a lower GNRI is an independent risk factor for both brain infarction and hemorrhage in patients who are receiving maintenance hemodialysis.

Impact of health-related quality of life on survival after dialysis initiation: a prospective cohort study in Korea

Background

The effect of each health-related quality of life (HRQOL) component on hemodialysis prognosis has not been well studied. We aimed to investigate the clinical factors associated with HRQOL and the effect of HRQOL after dialysis initiation on long-term survival in an Asian population.

Methods

A total of 568 hemodialysis patients were included from a nationwide prospective cohort study. HRQOL was evaluated using the Kidney Disease Quality of Life (KDQOL) Short FormTM 1.3 at 3 months after dialysis initiation. The effect of each KDQOL item score on mortality was analyzed. Multivariable Cox analysis was performed after adjusting for age, sex, modified Charlson comorbidity index, and causes of primary kidney disease.

Results

Old age, diabetes mellitus, high comorbidities, and low serum albumin levels were associated with poor physical health status. Decreased urine output was associated with both poor physical and mental health status. The scores of 3 indices in the kidney disease domain (effect of kidney disease, social support, and dialysis staff encouragement) showed significant associations with mortality, as did the 3 indices (physical function, physical role limitation, and body pain) in the physical health domain. Neither the 4 indices in the mental health domain nor the mental composite score showed a significant association with mortality. However, a high physical composite score was associated with decreased overall patient mortality (P = 0.003). The effect of physical composite score on survival was prominent among young or middle-aged groups.

Conclusion

Poor physical health status 3 months after hemodialysis start correlates significantly with overall mortality.

Weighing the waitlist: Weight changes and access to kidney transplantation among obese candidates

High body mass index is a known barrier to access to kidney transplantation in patients with end-stage kidney disease. The extent to which weight and weight changes affect access to transplantation among obese candidates differentially by race/ethnicity has received little attention. We included 10 221 obese patients waitlisted for kidney transplantation prior to end-stage kidney disease onset between 1995–2015. We used multinomial logistic regression models to examine the association between race/ethnicity and annualized change in body mass index (defined as stable [-2 to 2 kg/m²/year], loss [>2 kg/m²/year] or gain [>2 kg/m²/year]). We then used Fine-Gray models to examine the association between weight changes and access to living or deceased donor transplantation by race/ethnicity, accounting for the competing risk of death. Overall, 29% of the cohort lost weight and 7% gained weight; 46% received a transplant. Non-Hispanic blacks had a 24% (95% CI 1.12–1.38) higher odds of weight loss and 22% lower odds of weight gain (95% CI 0.64–0.95) compared with non-Hispanic whites. Hispanics did not differ from whites in their odds of weight loss or weight gain. Overall, weight gain was associated with lower access to transplantation (HR 0.88 [95% CI 0.79–0.99]) compared with maintenance of stable weight, but weight loss was not associated with better access to transplantation (HR 0.96 [95% CI 0.90–1.02]), although this relation differed by baseline body mass index and for recipients of living versus deceased donor organs. For example, weight loss was associated with improved access to living donor transplantation (HR 1.24 [95% CI 1.07–1.44]) in whites but not in blacks or Hispanics. In a cohort of obese patients waitlisted before dialysis, blacks were more likely to lose weight and less likely to gain weight compared with whites. Weight loss was only associated with improved access to living donor transplantation among whites. Further studies are needed to understand the reasons for the observed associations.

Association of Pulmonary Hypertension With End-Stage Renal Disease Among the Obese Population

Introduction

Pulmonary hypertension (PH) is a known complication that occurs in patients of end-stage renal disease (ESRD) that have an arteriovenous fistula (AVF) for hemodialysis (HD). It is defined as pulmonary artery pressure (PAP) of greater than 30 mmHg on echocardiography. The presence of PH in ESRD is an independent risk factor and decreases the survival likelihood among HD patients. Unexplained PH is frequently seen in ESRD following AVF.

Obesity can lead to various complications, such as sleep apnea, cardiac complications, pulmonary hypertension, and mortality. Data on the prevalence of coexisting PH and obesity are scarce.

Obese patients often have increased albumin excretion rates (AER) that can lead to early renal impairment and an increase in intraglomerular pressure, which may increase the risk of cardiovascular (CV) morbidity and mortality.

Therefore, the study aimed to evaluate and compare the associated PH and obesity separately and collectively among ESRD patients.

Methods

This comparative cross-sectional study was conducted in a tertiary care public sector hospital with the approval of the medical ethics review board committee.

The study enrolled all consecutive patients with ESRD as defined by having an estimated glomerular filtration rate (GFR) of <15 mL/min/1.7 3 m² from April 2017 till March 2019, who presented to our facility. These patients underwent dialysis twice or thrice a week, each session lasting three to four hours approximately. On initial encounter, trans-thoracic echocardiography (TTE) was done by the cardiologist to diagnose pulmonary hypertension.

In addition, body mass index (BMI) was calculated for all patients, and the patients were categorized into underweight, normal, overweight, or obese. All patients underwent post-dialysis TTE at one hour or when patients were at the optimal dry weight. Systolic PAP and ejection fraction were measured, and pulmonary hypertension was defined as a PAP of 30 mmHg or greater on TTE.

ESRD patients that were diagnosed with PH prior to hemodialysis or had primary PH were excluded from the study. Only ESRD patients developing secondary PH after hemodialysis were included in the study.

The chi-square test was used to see the correlation of gender, ambulation status, smoking status, obesity, pulmonary hypertension, body mass index (BMI), and pulmonary hypertension and obesity combined on the final outcome. A p-value of 0.05 was considered significant. Odds ratio (OR) and relative risk (RR) were calculated for pulmonary hypertension and obesity combined, obesity, and pulmonary hypertension in the final outcome.

Results

The study enrolled 204 patients with a mean age of 46.23 (±20.45 SD) having higher female participation of 108 (52.9%), whereas 96 (47.1%) were males. The average weight of the cohort was 66.78 kg (±22.98 SD) with a mean BMI of 29.91 kg/m² (±13.29SD), 52 (25.5%) patients were underweight, 40 (19.6%) had a normal BMI, 29 (14.2%) were overweight, and 83 (40.7%) patients were obese.

Pulmonary hypertension and obesity combined were observed in 48 (23.5%) of the cases and there was a 4.60 relative risk of death among these individuals, with an odds ratio of 13.35 and a p-value of 0.00.

Conclusion

The study shows a strong synergistic effect of pulmonary hypertension and obesity towards the final survival outcome in ESRD patients who are on hemodialysis.

Obesity After Kidney Transplantation-Results of a KTx360°Substudy

OBJECTIVE

There is solid evidence that kidney transplant (KTx) patients are susceptible to weight gain after transplantation. Post-transplantation obesity [body mass index (BMI) ≥ 30 kg/m2] seems to be associated with higher risks of hypertension, dyslipidemia, diabetes mellitus, and cardiovascular events, while there are contradicting findings regarding the association between obesity and mortality, graft failure after transplantation as well as other variables. We aimed to evaluate the course of weight after KTx and to assess the prevalence of post-transplant obesity in a large sample of German KTx patients. Further, we focused on potential associations between weight gain, obesity, and BMI after transplantation with sociodemographic, medical, psychological [levels of anxiety and depression measured with the Hospital Anxiety and Depression Scale (HADS)], and donation-specific variables.

METHODS

In a structured post-transplant care program 433 KTx patients were evaluated at Hannover Medical School. Information on the pre-transplant body weight/dry weight of dialysis patients was taken from the electronic patient charts. At post-transplant assessment body weight was measured in the transplant center. For statistical analyses, descriptive statistics, analyses of variance, tests for correlations, and regression analyses were used.

RESULTS

Mean age was 51.3 years, 59% were male and 26.3% had ≥12 years of school attendance. Regarding somatic conditions 6.0% were suffering from type 2 diabetes mellitus, 6.9% were affected by new-onset diabetes after transplantation (NODAT), and the mean estimated glomerular filtration rate (eGFR) was 47.7 ml/min/1.73m2. The prevalence rates of obesity before and after kidney transplantation were 14.8 and 19.9%, respectively. This represents an increase of 34%. Obesity after transplantation was associated with higher rates of type 2 diabetes mellitus and of NODAT. Additionally, there was an association between increasing pre-transplant as well as post-transplant BMI and decreasing eGFR. Higher age and female sex were associated with higher rates of post-transplant obesity.

CONCLUSIONS

Our results suggest that obesity represents a serious problem in KTx patients, especially regarding the association between increasing BMI and decreasing graft functioning (eGFR). However, this aspect is often overlooked and information on effective treatment options for these patients are scarce making further research on this topic necessary.

Correlation between body composition measurement by bioelectrical impedance analysis and intradialytic hypotension

OBJECTIVE

To explore the correlation between body composition measurement by bioelectrical impedance analysis (BIA) and intradialytic hypotension (IDH).

METHODS

The clinical data of 127 patients with end-stage renal disease (ESRD) who underwent regular dialysis in the Blood Purification Center of the Second Affiliated Hospital of Chongqing Medical University were retrospectively analyzed. According to the occurrence of IDH, the patients were divided into IDH group and intradialytic normotension group. The difference in body composition measured by BIA and its relationship with IDH were compared between the two groups.

RESULTS

Compared with intradialytic normotension group, the intracellular water (ICW) ratio (P = 0.009), extracellular water (ECW) ratio (P = 0.029), total body water (TBW) ratio (P = 0.012), protein ratio (P = 0.010), soft lean mass (SLM) ratio (P = 0.011), fat-free mass (FFM) ratio (P = 0.012) and skeletal muscle mass (SMM) ratio (P = 0.009) in IDH group were significantly decreased. However, the fat mass (FM) ratio (P = 0.016), percentage body fat (PBF) ratio (P = 0.001), extracellular water/total body water (ECW/TBW) ratio (P = 0.036), extracellular water/total body water in trunk (ECW/TBWT) ratio (P = 0.045) and visceral fat area (VFA) (P = 0.003) in IDH group were significantly increased when compared with intradialytic normotension group. In addition, there was a positive correlation between systolic blood pressure (SBP) during IDH and ECW ratio, ECW/TBW ratio, and ECW/TBWTR ratio before dialysis.

CONCLUSIONS

The body composition of dialysis patients is closely related to the occurrence of IDH. Strengthening the body composition management of dialysis patients outside the hospital may reduce the occurrence of IDH and improve the long-term prognosis of dialysis patients.

Effect of a pedometer-based walking intervention on body composition in patients with ESRD: a randomized controlled trial

BACKGROUND

A randomized trial of a pedometer-based intervention with weekly activity goals led to a modest increase in step count among dialysis patients. In a secondary analysis, we investigated the effect of this intervention on body composition.

METHODS

Sixty dialysis patients were randomized to standard care or a 6-month program consisting of 3 months of pedometers and weekly step count targets and 3 months of post-intervention follow-up. We obtained bioelectrical impedance spectroscopy (BIS) data on 54 of these patients (28 control, 26 intervention) and used linear mixed-modeling (adjusted for sex and dialysis modality) to estimate differences in change in total-body muscle mass (TBMM) adjusted for height2, fat mass (kg), and body mass index (BMI) (kg/m2) between control and intervention groups.

RESULTS

The median age of participants was 57.5 years (53-66), and 76% were men. At baseline, there was no significant difference between groups in age, BMI, race, or body composition, but there were more men in the intervention group. After 3 months, patients in the intervention group increased their average daily steps by 2414 (95% CI 1047, 3782) more than controls (p < 0.001), but there were no significant differences in body composition. However, at 6 months, participants in the intervention had a significantly greater increase from baseline in TBMM of 0.7 kg/m2 (95% CI 0.3, 1.13), decrease in fat mass (- 4.3 kg [95% CI -7.1, - 1.5]) and decrease in BMI (- 1.0 kg/m2 [95% CI -1.8, - 0.2]) relative to controls. In post-hoc analysis, each increase of 1000 steps from 0 to 3 months was associated with a 0.3 kg decrease in fat mass (95% CI 0.05, 0.5) from 0 to 6 months, but there was no dose-response relationship with TBMM/ht2 or BMI.

CONCLUSION

A pedometer-based intervention resulted in greater decreases in fat mass with relative preservation of muscle mass, leading to a greater decrease in BMI over time compared with patients not in the intervention. These differences were driven as much by worsening in the control group as by improvement in the intervention group. Step counts had a dose-response relationship with decrease in fat mass.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT02623348). 02 December 2015.

Approaches to Obesity Management in Dialysis Settings: Renal Dietitian Perspectives

OBJECTIVES

Over 40% of individuals in the United States with end-stage kidney disease have obesity. Little is known about renal dietitian perspectives on obesity management in the setting of dialysis dependence.

DESIGN AND METHODS

An online 21-item survey was distributed to 118 renal dietitians via individual outreach and a professional organization e-mail listserv. Four themes were explored: the burden of obesity among dialysis patients, concepts of healthy weight loss, weight loss approaches, and challenges of obesity management in dialysis settings. Respondents were asked to rank approaches and biomarkers for obesity management from 0 (least important or not used) to 100 (most important). Free text fields were provided in each category for additional comments.

RESULTS

Thirty-one renal dietitians responded to the survey (26% response rate). The majority of respondents (90%) indicated that access to kidney transplantation was the main reason that dialysis patients with obesity desired weight loss. Calorie restriction was rated as the most common weight loss approach, and dry weight as the most important weight loss biomarker. Nearly 40% of respondents do not alter their nutritional approach when dialysis patients with obesity are losing weight, and 42% of respondents do not monitor changes in waist circumference. Exercise, diet counseling, and stress management were variably prioritized as weight loss management strategies. Barriers to obesity management in dialysis settings included lack of time, lack of training in weight loss counseling, and gaps in current renal nutritional guidelines.

CONCLUSION

Despite the high prevalence of obesity among individuals with end-stage kidney disease, the results of this survey suggest that current approaches to obesity management in dialysis settings are highly variable. Many renal dietitians lack time to counsel patients on healthy weight loss strategies. Nutritional guidelines are also needed to support people with dialysis dependence and obesity who desire or require weight loss.

Creatinine: From physiology to clinical application

Estimating static kidney function accurately and detecting changes in kidney function in a timely fashion are challenging but critically important tasks. Serum creatinine is the most widely used functional biomarker of the kidney. However, its use is associated with substantial shortcomings. Understanding these shortcomings is critical in allowing accurate interpretation of creatinine values and translating them into changes in kidney function. In this review, the pathways involved in creatinine generation and metabolism as well as the techniques involved in measuring creatinine concentrations are discussed. This allows for the discussion of the value and pitfalls in using creatinine as a marker of kidney function. In addition, information regarding alternative functional biomarkers of the kidney is provided.