Obesity and survival on dialysis

Impact of pretransplantation malnutrition risk on the clinical outcome and graft survival of kidney transplant patients

BACKGROUND

The prevalence of malnourished patients before transplantation and the influence of malnutrition on graft and patient outcomes remain underestimated, despite being associated with higher postoperative morbidity and mortality. This study aimed to develop an easy nutritional screening tool and evaluate the impact of nutritional status on clinical outcome, graft survival (GS) and mortality risk in kidney transplant patients (KTP).

METHODS

In this retrospective cohort study including 451 KTP, we developed a score by using anthropometric, clinical, and laboratory measures performed in the pretransplant evaluation. The patients were stratified into 3 groups according to the final score: G1 (0 or 1 point)=low risk, G2 (2 to 4 points)=moderate risk, and G3 (>5 points)=high risk of malnutrition. The patients were monitored after transplantation at least 1 to 10 years.

RESULTS

Stratifying the 451 patients based on the pretransplant risk score, G1, G2, and G3 were composed of 90, 292, and 69 patients, respectively. Patients from G1 maintained the lowest serum creatinine levels at hospital discharge when compared with others (p = 0.012). The incidence of infection in the patients from G3 was higher than patients from G1 and G2 (p = 0.030). G3 recipients showed worse GS than G1 patients (p = 0.044). G3 patients showed almost threefold higher risk for graft loss (HR 2.94, 95% CI 1.084-7.996).

CONCLUSIONS

KTP with higher malnutrition risk score were associated with worse outcomes and GS. The nutritional screening tool is easy to be used in clinical practice to evaluate the patient in preparation for kidney transplant.

Pressure Ulcer Diagnosis Is Associated with Increased Mortality in Patients with End-Stage Renal Disease: A Retrospective Study

Pressure ulcers are associated with multiple comorbidities and annually affect approximately 3 million Americans, directly accounting for approximately 60,000 deaths per year. Because patients with end-stage renal disease (ESRD) are known to present with unique factors which impair wound healing, pressure ulcers diagnosed in ESRD patients might independently increase the risk of mortality. To investigate the association between pressure ulcer diagnosis and mortality risk in the ESRD population, a retrospective analysis of the United States Renal Data System (USRDS) database was performed. The records of 1,526,366 dialysis patients who began therapy between 1 January 2005 and 31 December 2018 were included. Our analysis showed that the diagnosis of pressure ulcers in this population was independently associated with mortality even after controlling for confounding factors (p < 0.001). A Kaplan-Meier survival analysis demonstrated reduced survival in patients with a pressure ulcer diagnosis compared to those without a pressure ulcer diagnosis. These results establish pressure ulcers as a significant independent risk factor for mortality, as well as suggesting several comorbidities as potential risk factors for pressure ulcers in the ESRD population.

Association between inflammatory potential of diet and markers of malnutrition in haemodialysis patients

In this study, we aimed to examine the relationship between energy-adjusted dietary inflammatory index (E-DII) and a comprehensive profile of malnutrition in Iranian haemodialysis (HD) patients. In this cross-sectional study, 291 participants on HD for at least 6 months before enrollment were included. The current dietary intakes of participants were assessed using a 4-d diet diary-assisted recall, including 2 non-dialysis days and 2 dialysis days to calculate E-DII. To determine the malnutrition status of HD patients, BMI, subjective global assessment (SGA), dialysis malnutrition score (DMS) and malnutrition inflammation score (MIS) were used. Overall, 291 HD patients comprised our study population. After controlling for potential confounders, E-DII was associated with a higher risk of malnutrition, as evidenced by SGA (OR = 2·23; 95 % CI: 1·11, 4·49), DMS (OR = 2·31; 95 % CI: 1·16, 4·60) and MIS (OR = 2·50; 95 % CI: 1·28, 4·88). No significant association was detected between E-DII and BMI either before (OR = 1·78; 95 % CI: 0·83, 3·81) or after adjustment for possible confounders (OR = 1·43; 95 % CI: 0·58, 3·54). This study showed that E-DII was significantly associated with reliable malnutrition markers including SGA, DMS and MIS in HD patients. However, further longitudinal studies are warranted to infer a cause-and-effect relationship between DII and malnutrition.

COVID-19 Risk Factors and Mortality Outcomes Among Medicare Patients Receiving Long-term Dialysis

Importance

There is a need for studies to evaluate the risk factors for COVID-19 and mortality among the entire Medicare long-term dialysis population using Medicare claims data.

Objective

To identify risk factors associated with COVID-19 and mortality in Medicare patients undergoing long-term dialysis.

Design, Setting, and Participants

This retrospective, claims-based cohort study compared mortality trends of patients receiving long-term dialysis in 2020 with previous years (2013-2019) and fit Cox regression models to identify risk factors for contracting COVID-19 and postdiagnosis mortality. The cohort included the national population of Medicare patients receiving long-term dialysis in 2020, derived from clinical and administrative databases. COVID-19 was identified through Medicare claims sources. Data were analyzed on May 17, 2021.

Main Outcomes and Measures

The 2 main outcomes were COVID-19 and all-cause mortality. Associations of claims-based risk factors with COVID-19 and mortality were investigated prediagnosis and postdiagnosis.

Results

Among a total of 498 169 Medicare patients undergoing dialysis (median [IQR] age, 66 [56-74] years; 215 935 [43.1%] women and 283 227 [56.9%] men), 60 090 (12.1%) had COVID-19, among whom 15 612 patients (26.0%) died. COVID-19 rates were significantly higher among Black (21 787 of 165 830 patients [13.1%]) and Hispanic (13 530 of 86 871 patients [15.6%]) patients compared with non-Black patients (38 303 of 332 339 [11.5%]), as well as patients with short (ie, 1-89 days; 7738 of 55 184 patients [14.0%]) and extended (ie, ≥90 days; 10 737 of 30 196 patients [35.6%]) nursing home stays in the prior year. Adjusting for all other risk factors, residing in a nursing home 1 to 89 days in the prior year was associated with a higher hazard for COVID-19 (hazard ratio [HR] vs 0 days, 1.60; 95% CI 1.56-1.65) and for postdiagnosis mortality (HR, 1.31; 95% CI, 1.25-1.37), as was residing in a nursing home for an extended stay (COVID-19: HR, 4.48; 95% CI, 4.37-4.59; mortality: HR, 1.12; 95% CI, 1.07-1.16). Black race (HR vs non-Black: HR, 1.25; 95% CI, 1.23-1.28) and Hispanic ethnicity (HR vs non-Hispanic: HR, 1.68; 95% CI, 1.64-1.72) were associated with significantly higher hazards of COVID-19. Although home dialysis was associated with lower COVID-19 rates (HR, 0.77; 95% CI, 0.75-0.80), it was associated with higher mortality (HR, 1.18; 95% CI, 1.11-1.25).

Conclusions and Relevance

These results shed light on COVID-19 risk factors and outcomes among Medicare patients receiving long-term chronic dialysis and could inform policy decisions to mitigate the significant extra burden of COVID-19 and death in this population.

Macrophage and adipocyte interaction as a source of inflammation in kidney disease

In obesity, adipose tissue derived inflammation is associated with unfavorable metabolic consequences. Uremic inflammation is prevalent and contributes to detrimental outcomes. However, the contribution of adipose tissue inflammation in uremia has not been characterized. We studied the contribution of adipose tissue to uremic inflammation in-vitro, in-vivo and in human samples. Exposure to uremic serum resulted in activation of inflammatory pathways including NFκB and HIF1, upregulation of inflammatory cytokines/chemokines and catabolism with lipolysis, and lactate production. Also, co-culture of adipocytes with macrophages primed by uremic serum resulted in higher inflammatory cytokine expression than adipocytes exposed only to uremic serum. Adipose tissue of end stage renal disease subjects revealed increased macrophage infiltration compared to controls after BMI stratification. Similarly, mice with kidney disease recapitulated the inflammatory state observed in uremic patients and additionally demonstrated increased peripheral monocytes and inflammatory polarization of adipose tissue macrophages (ATMS). In contrast, adipose tissue in uremic IL-6 knock out mice showed reduced ATMS density compared to uremic wild-type controls. Differences in ATMS density highlight the necessary role of IL-6 in macrophage infiltration in uremia. Uremia promotes changes in adipocytes and macrophages enhancing production of inflammatory cytokines. We demonstrate an interaction between uremic activated macrophages and adipose tissue that augments inflammation in uremia.

Effects of Sarcopenia on Prognosis After Resection of Gallbladder Cancer

BACKGROUND

This study aimed to determine the prognostic significance of radiographic sarcopenia (RS) in patients with gallbladder cancer (GBC).

METHODS

From March 2001 to December 2013, 158 GBC patients who underwent curative intent surgery were included. The presence of RS was determined by skeletal muscle mass index using abdominal computed tomography.

RESULTS

The 1-, 3-, and 5-year overall survival (OS) rates were 63.6%, 41.9%, and 36.4%, respectively, for patients with RS (n = 88), and 84.3%, 62.6%, and 54.3%, respectively, for those without RS (n = 70) (P = 0.006). Multivariate analysis showed that RS (hazard rate [HR] 1.704, P = 0.024) was a significant prognostic factor for patient survival, as well as disease stage (IV: HR 7.181, P < 0.001), radicality (HR 2.830, P = 0.001), adjuvant therapy (HR 0.537, P = 0.017), and intraoperative blood loss ≥ 1 L (HR 1.851, P = 0.023).

CONCLUSIONS

This study showed a significant association between RS and OS in GBC patients. Because RS is the only significant prognostic factor that can be evaluated preoperatively, its assessment would be helpful to provide early preventive therapy allowing the maintenance of muscle mass and patient-tailored treatment based on their physiologic reserves (e.g., skeletal muscle mass).

Dietary intake as a predictor for all-cause mortality in hemodialysis subjects (NUGE-HD study)

This study aimed to identify the factors capable of mortality prediction in patients on hemodialysis, using a prospective cohort with three years of follow-up. We hypothesized that lack of clinical-metabolic control, impairment of nutritional status, and inadequate food consumption are risk factors for mortality in this population. This is a longitudinal study on a non-probabilistic sample of 85 adults and elderly patients undergoing hemodialysis, aged ≥ 18 years (66.0% male, 61.6±13.7 years). Data on anthropometric, biomarkers, body composition and food intake were obtained. Predictors of mortality were evaluated using Cox regression analysis. During the three years follow-up, 16 patients (18.8%) died. We observed that age (HR = 1.319, CI 95% = 1.131-1.538), calcium-phosphorus product (HR = 1.114, CI 95% = 1.031-1.205), ferritin (HR = 1.001, CI 95% = 1.001-1.002), nitric oxide (HR = 1.082, CI 95% = 1.006-1.164), and vitamin C intake (HR = 1.005, CI 95% = 1.001-1.009) were positively associated with mortality. Serum iron (HR = 0.717, CI 95% = 0.567-0.907), triceps skinfold thickness (HR = 0.704, CI 95% = 0.519-0.954), lean mass (HR = 0.863, CI 95% = 0.787-0.945), and the ratio of dietary monounsaturated/polyunsaturated fat (HR = 0.022, CI 95% = 0.001-0.549) were independent negative predictors of mortality. Our results suggest that dietary intake is also a predictor of mortality in patients on hemodialysis, besides nutritional status, body composition, oxidative stress, inflammation, and bone metabolism, indicating the importance of evaluation of these factors altogether for better prognosis.

Genomic Analysis of an Obesity Paradox: A Microarray Study of the Aortas of Morbidly Obese Decedents With Mild and Severe Atherosclerosis

BACKGROUND

Atherosclerosis of the aorta and coronary arteries is still one of the major causes of death. We recently reported obesity paradox between body mass index and atherosclerosis of the aortas (AA) in morbidly obese decedent patients. The cause of this obesity paradox is unknown. The aim of the present study was to carry out genomic microarray analysis to determine gene expression profiles in the aortas of morbidly obese decedents with either mild or severe atherosclerosis of the aorta.

METHODS

Microarray studies using Affymetrix GeneChips Clariom D Human array chips were performed on the aortas obtained from 6 morbidly obese decedents, 3 of whom had minimal AA and 3 who had severe disease.

RESULTS

Group 1 (severe AA) and group 2 (mild AA) included 3 patients each. The patients were matched by age and body mass index. There were significant (P<0.005) differences in the expressions of 1067 genes between groups 1 and 2, including 602 upregulated and 465 downregulated genes.

CONCLUSIONS

Our data show significantly different gene signatures between morbidly obese decedents who have mild or severe AA, suggesting that genetic factors may be important contributors to the obesity paradox as it relates to aortic atherosclerosis. Further studies are warranted to define differences in protein expression in the aortas of these 2 groups to further elucidate the cause of this obesity paradox.

Uremia induces adipose tissue inflammation and muscle mitochondrial dysfunction

Background.

End-stage renal disease (ESRD) is associated with inflammation and increased reactive oxygen species (ROS). Inflammation and oxidative stress are associated with several complications of ESRD. The aim of this study was to determine histological characteristics of adipose tissue and muscle mitochondrial function in uremia and its relationship with inflammation.

Methods.

ESRD patients ( n  = 18) and controls ( n  = 6) were enrolled for studies of adipose and muscle tissue by immunohistochemistry and western blot. In a uremic muscle cell model, C2C12 cells were exposed to uremic serum and inflammatory cytokines. Mitochondrial function was studied by MitoTracker Orange, translocase of the mitochondrial outer membrane 20 (TOMM20) and mitochondrial oxidative phosphorylation complex subunit expression.

Results.

ESRD patients had increased macrophage infiltration in subcutaneous and visceral adipose tissue compared with controls, even in nonobese ESRD patients (P < 0.05). Compared with controls, TOMM20 expression in muscle tissue was lower in ESRD, consistent with reduced mitochondrial function (P < 0.05). C2C12 exposed to uremia had decreased mitotracker intensity (P < 0.05) and the reduced mitochondrial function was rescued by N-acetyl cysteine (P < 0.01). Similarly, C2C12 cells exposed to tumor necrosis factor α (TNF-α)/interleukin-6 (IL-6) have decreased mitotracker intensity (P < 0.01) that was rescued with adiponectin (P < 0.05). C2C12 exposed to TNF-α, IL-6 and buthionine sulfoximine had decreased TOMM20 expression and cells exposed to TNF-α showed a decrease in subunits of mitochondrial complexes I and III.

Conclusion.

Our data indicate that uremia is associated with increased adipose tissue macrophage infiltration and concurrent muscle tissue mitochondrial dysfunction induced by inflammation/ROS. Adipose tissue is a potential source of inflammation in ESRD that is not due to increased adiposity and may contribute to mitochondrial dysfunction in uremia.

Association Between Comprehensive Nutritional Scoring System (CNSS) and Outcomes of Continuous Ambulatory Peritoneal Dialysis Patients

BACKGROUND/AIMS

The presence of protein-energy wasting (PEW) among dialysis patients is a crucial risk factor for outcomes. The complicated pathogenesis of PEW makes it difficult to assess and treat. This single-center retrospective study focuses on the association between nutritional markers and the outcomes of continuous ambulatory peritoneal dialysis(CAPD) patients, aiming to establish a practical comprehensive nutritional scoring system for CAPD patients.

METHODS

924 patients who initiated peritoneal dialysis in our center from January 1st,2005 to December 31st,2015 were enrolled. Comprehensive nutritional scoring system(CNSS) was based on items including SGA, BMI, ALB, TC, MAC and TSF. We divide patients into 3 groups according to their CNSS score. Outcomes including mortality, hospitalization days and hospitalization frequency were compared between 3 grades.

RESULTS

The CNSS grade correlated significantly with hospitalization days (P<0.05). Both categorized CNSS grade (HR:0.56; 95% CI:0.41-0.78; P = 0.001) and continuous CNSS score (HR:0.87; 95% CI: 0.80-0.94; P = 0.001) independently protect PD patients from all-cause mortality.

CONCLUSION

CNSS provides an integrated scoring system with significant associations with hospitalization and mortality in PD patients. The CNSS grade differentiates patients with malnutritional risk and independently predicts high risk of morbidity and mortality.

Metabolic syndrome and new onset diabetes after kidney transplantation

AIMS

The metabolic syndrome developed after kidney transplantation is the result of several factors which are identical with the risk factors in normal population, however, also some factors typical for the transplanted patients-especially the effects of immunosuppressive therapy.

MATERIAL AND METHODS

In the groupof 268 patients after kidney transplantation, which had no type 1 or type 2 diabetes mellitus before transplantation, we identified patients with metabolic syndrome(based on IDF criteria), 12 months from the kidney transplantation. In all patients, we recorded the following parameters: age at the time of transplantation, type of immunosuppression, waist measure, the value of triacylglycerols, the value of HDL cholesterol, presence of arterial hypertension, andthe value of glycaemia in fasting state (or presence of diabetes mellitus). The groupof patients was divided into the control group and the group of patients with metabolic syndrome.

RESULTS

The average age of patients was 46.1±11.6years. The control group included 149 patients (55.6%),and we identified the metabolicsyndromein 119patients (44.4%). The patients with metabolicsyndrome were significantly older (P<0.0001), had significantly larger waist (both the entiregroup and the males andfemales) P<0.0001.The femaleswith metabolic syndrome had significantly lower value of HDL-cholesterol (P=0.0013), and significantly higher number of patients with metabolic syndrome had hyperglycaemia in fasting state or diabetes mellitus (P=0.0006).

CONCLUSION

By controlling the weight and waist, we may identify the risk patients for development of metabolic syndrome after kidney transplantation.

Mortality after Renal Allograft Failure and Return to Dialysis

INTRODUCTION

The outcomes of patients who fail their kidney transplant and return to dialysis (RTD) has not been investigated in a nationally representative sample. We hypothesized that variations in management of transplant chronic kidney disease stage 5 leading to kidney allograft failure (KAF) and RTD, such as access, nutrition, timing of dialysis, and anemia management predict long-term survival.

METHODS

We used an incident cohort of patients from the United States Renal Data System who initiated hemodialysis between January 1, 2003 and December 31, 2008, after KAF. We used Cox regression analysis for statistical associations, with mortality as the primary outcome.

RESULTS

We identified 5,077 RTD patients and followed them for a mean of 30.9 ± 22.6 months. Adjusting for all possible confounders at the time of RTD, the adjusted hazards ratio (AHR) for death was increased with lack of arteriovenous fistula at initiation of dialysis (AHR 1.22, 95% CI 1.02-1.46, p = 0.03), albumin <3.5 g/dL (AHR 1.33, 95% CI 1.18-1.49, p = 0.0001), and being underweight (AHR 1.30, 95% CI 1.07-1.58, p = 0.006). Hemoglobin <10 g/dL (AHR 0.96, 95% CI 0.86-1.06, p = 0.46), type of insurance, and zip code-based median household income were not associated with higher mortality. Glomerular filtration rate <10 mL/min/1.73 m2 at time of dialysis initiation (AHR 0.83, 95% CI 0.75-0.93, p = 0.001) was associated with reduction in mortality.

CONCLUSIONS

Excess mortality risk observed in patients starting dialysis after KAF is multifactorial, including nutritional issues and vascular access. Adequate preparation of patients with failing kidney transplants prior to resuming dialysis may improve outcomes.

Gastric Bypass in Chronic Renal Failure and Renal Transplant

BACKGROUND

Morbid obesity has reached epidemic proportions in developed nations worldwide, causing considerable mortality and increased healthcare expenditures. The use of gastric bypass surgery to achieve weight loss in morbidly obese patients with chronic renal failure (CRF) and postrenal transplant patients has not been studied adequately.

METHODS

Forty-one patients with different stages of CRF (25 already receiving dialysis) underwent a gastric bypass (GBP), and an additional 10 patients underwent a GBP after becoming morbidly obese after transplantation.

RESULTS

Of the 41 patients with CRF, 5 stabilized or resolved their kidney disease and 9 underwent successful transplantation. These patients had a loss of 68% excess body mass index (BMI) by 12 months after GBP. Of the 10 patients with GBP after transplant, the mean loss of excess BMI was 70.5%. There were no in-hospital or 30-day mortalities, but 8 of the 51 patients died from 112 to 2869 days postoperatively, 7 from cardiac or vascular events and 1 from an automobile accident. This compares with an approximate 10% mortality per year for patients receiving dialysis. Comorbid conditions associated with morbid obesity improved in all patients and permitted eligibility for transplantation.

CONCLUSIONS

GBP for massive weight reduction in morbidly obese renal failure and transplant patients leads to a reduction in comorbid conditions that are associated with an increased risk for cardiovascular deaths. There was no operative mortality in this series, and all but 1 death were related to previously existing disease of the cardiovascular system.

Incidence of Diabetes Mellitus After Kidney Transplantation in Slovakia: Multicentric, Prospective Analysis

BACKGROUND

The incidence rate of post-transplant diabetes mellitus (PTDM) after kidney transplantation (KT) is 5% to 40%. The objective of this analysis was to identify the risk factors of PTDM after KT in the Slovak Republic (SR).

METHODS

In the group of 133 patients/non-diabetics, we identified the risk factors of PTDM in the monitored period of 12 months from transplantation.

RESULTS

The incidence of PTDM in the SR in 2014 was 38.3%. By logistic regression, we discovered that the age at the time of KT [odds ratio, 1.0885; 95% CI, 1.0222-1.1592; P = .0082], the value of body mass index (BMI) at the time of KT [odds ratio, 1.4606; 95% CI, 1.0099-2.1125; P = .0442], and the value of insulin resistance index (homeostatic model assessment for insulin resistance) at the time of KT [odds ratio, 2.5183; 95% CI, 1.7119-3.4692; P < .0001] represented predictive factors of PTDM. The independent risk factors of PTDM in our group were age at the time of KT of more than 60 years [HR 0.3871; 95% CI 0.1659-1.7767; P = .0281], waist circumference at the time of KT in men more than 94 cm and in women more than 80 cm [HR, 3.4833; 95% CI, 1.2789-9.4878 (P = .0146)], BMI at the time of KT [HR 3.0011; 95% CI 1.0725-8.3977 (P = .0363)], and triacylglycerols at the time of KT more than 1.7 mmol/L [HR, 2.9763; 95% CI, 1.0141-8.7352; P = .0471].

CONCLUSIONS

In the group of Slovak patients after kidney transplantation, the dominating risk factor for PTDM development was insulin resistance prior to KT.

Nutrition Interventions in Chronic Kidney Disease

Dietary modification is recommended in the management of chronic kidney disease (CKD). Individuals with CKD often have multiple comorbidities, such as high blood pressure, diabetes, obesity, and cardiovascular disease, for which dietary modification is also recommended. As CKD progresses, nutrition plays an important role in mitigating risk for cardiovascular disease and decline in kidney function. The objectives of nutrition interventions in CKD include management of risk factors, ensuring optimal nutritional status throughout all stages of CKD, preventing buildup of toxic metabolic products, and avoiding complications of CKD. Recommended dietary changes should be feasible, sustainable, and suited for patients' food preferences and clinical needs.

Dietary inflammatory index is associated with serum C-reactive protein and protein energy wasting in hemodialysis patients: A cross-sectional study

BACKGROUND/OBJECTIVE

Malnutrition and inflammation are reported as the most powerful predictors of mortality and morbidity in hemodialysis (HD) patients. Diet has a key role in modulating inflammation and dietary inflammatory index (DII) is a new tool for assessment of inflammatory potential of diet. The aim of this study was to evaluate the application of DII on dietary intake of HD patients and examine the associations between DII and malnutrition-inflammation markers.

SUBJECTS/METHODS

A total of 105 subjects were recruited for this cross-sectional study. Anthropometric measurements, 3-day dietary recall, and pre-dialysis biochemical parameters were recorded for each subject. Subjective global assessment (SGA), which was previously validated for HD patients, and malnutrition inflammation score (MIS) were used for the diagnosis of protein energy wasting. DII was calculated according to average of 3-day dietary recall data.

RESULTS

DII showed significant correlation with reliable malnutrition and inflammation indicators including SGA (r = 0.28, P < 0.01), MIS (r = 0.28, P < 0.01), and serum C-reactive protein (CRP) (r = 0.35, P < 0.001) in HD patients. When the study population was divided into three subgroups according to their DII score, significant increasing trends across the tertiles of DII were observed for SGA score (P = 0.035), serum CRP (P = 0.001), dietary energy (P < 0.001), total fat (P < 0.001), saturated fatty acids (P < 0.001), polyunsaturated fatty acids (P = 0.006), and omega-6 fatty acids (P = 0.01) intakes.

CONCLUSION

This study shows that DII is a good tool for assessing the overall inflammatory potential of diet in HD patients.

Does the obesity survival paradox of dialysis patients differ with age?

BACKGROUND

The obesity paradox of hemodialysis patients (the association between obesity and survival) could be modified by age. We hypothesize that whereas obesity associates with survival in elderly patients, it behaves as a mortality risk marker in younger individuals.

METHODS

Retrospective study of 2002-2010 adult incident hemodialysis to analyze the relationship between body mass index (BMI) and annual body weight changes with mortality in different age strata.

RESULTS

Included in the study were 6,290 individuals. A progressive decrease in mortality was associated with increasing BMI ranges. Both annual body weight gains and losses were associated with mortality. Similar results were observed in elderly individuals, but in the BMI values of young patients, there were no significant differences in mortality.

CONCLUSION

There is a survival benefit with increasing BMI in patients overall. However, while these results persist in patients >65 years, in young people there are no changes in mortality. Patients with the highest inter-annual variability in weight have an increased risk.

The association between blood pressure level and serum uric acid concentration in hemodialysis patients

Background: High blood pressure is a common condition in hemodialysis patients. Uric acid, which is high in these patients due to decreased clearance, had been shown to positively correlate with blood pressure in animal studies.

Objectives: The goal of this investigation was to evaluate the impact of high uric acid level on blood pressure in these patients.

Patients and Methods: Ninety-one patients, on three times weekly hemodialysis, were studied. Uric acid levels were measured just before and after hemodialysis along with blood pressures before, during and after each session. Data were analyzed by SPSS 15. A P value less than 0.05 was considered significant.

Results: 40 (44%) of patients had serum uric acid ≥6 mg/dl. Before dialysis 51 (61%) and 19 (21%) had high systolic blood and diastolic blood pressures respectively. Also, 50 (55%) were with wide pulse pressure and 63 (69%) had high mean arterial pressure (MAP). Additionally 62 (68%) developed inter-dialysis hypotension. After measuring odds ratio for hyperuricemia in each group, we observed low risk of hypruricemia in the group with high systolic pressure (OR = 0.352; 95% CI: 0.147-0.844; P = 0.01), the high MAP group (OR = 0.382; 95% CI: 0.153-0.955; P = 0.03) and wide pulse pressure group (OR = 0.416; 95% CI: 0.177-0.975; P = 0.04). There was no association between high uric acid level and diastolic pressure (P = 0.11) and inter-dialysis hypotension (P = 0.33). No relationship was found between serum uric acid and KT/V (P = 0.2), normalized protein catabolic rate (nPCR) (P = 0.07) and body mass index (BMI) (P = 0.4).

Conclusions: This study showed paradoxical association between high uric acid level and high systolic pressure, high MAP and wide pulse pressure and these effects were independent of dialysis duration, dialysis efficacy and nutrition, assuming that these relationships could be due to reverse epidemiology in dialysis patients.

Intensive weight loss combining flexible dialysis with a personalized, ad libitum, coach-assisted diet program. A "pilot" case series

Obesity is a growing problem on dialysis. The best approach to weight loss has not been established. The risks of malnutrition may offset the advantages of weight loss. Personalized hemodialysis schedules, with an incremental approach, are gaining interest; to date, no studies have explored its potential in allowing weight loss. This case series reports on combining flexible, incremental hemodialysis, and intensive weight loss.

SETTING

a small Dialysis Unit, following incremental personalized schedules (2-6 sessions/week, depending on residual function), tailored to an equivalent renal clearance >12 mL/min. Four obese and two overweigh patients (5 male, 1 female; age: 40-63 years; body mass index [BMI] 31.1 kg/m(2)) were enrolled in a coach-assisted weight loss program, with an "ad libitum" approach (3-6 foods/day chosen on the basis of their glycemic index and glycemic load). The diet consists of 8 weeks of rapid weight loss followed by 8-12 weeks of maintenance; both phases can be repeated. This study measures weight loss, side effects, and patients' opinions. Over 12-30 months, all patients lost weight (median -10.3 kg [5.7-20], median ΔBMI-3.2). Serum albumin (pre-diet 3.78; post-diet 3.83 g/dL), hemoglobin (pre-diet 11; post-diet 11.2 g/dL), and acid-base balance (HCO(3) pre-diet: 23.3; post-diet: 23.4 mmol/L) remained stable, with decreasing needs for erythropoietin and citrate or bicarbonate supplements. Calcium-phosphate-parathyroid hormone (PTH) balance improved (PTH-pre 576; post 286 pg/mL). Three out of 4 hypertensive patients discontinued, 1 decreased antihypertensives. None experienced severe side effects. Patient satisfaction was high (9 on a 0-10 analog scale). Personalized, incremental hemodialysis schedules allow patient enrollment in intensive personalized weight loss programs, with promising results.

Serum 25-hydroxy vitamin D concentrations are more deficient/insufficient in peritoneal dialysis than haemodialysis patients in a sunny climate

BACKGROUND

Research has identified associations between serum 25(OH)D and a range of clinical outcomes in chronic kidney disease and wider populations. The present study aimed to investigate vitamin D deficiency/insufficiency in dialysis patients and the relationship with vitamin D intake and sun exposure.

METHODS

A cross-sectional study was used. Participants included 30 peritoneal dialysis (PD) (43.3% male; 56.87 ± 16.16 years) and 26 haemodialysis (HD) (80.8% male; 63.58 ± 15.09 years) patients attending a department of renal medicine. Explanatory variables were usual vitamin D intake from diet/supplements (IU day(-1) ) and sun exposure (min day(-1) ). Vitamin D intake, sun exposure and ethnic background were assessed by questionnaire. Weight, malnutrition status and routine biochemistry were also assessed. Data were collected during usual department visits. The main outcome measure was serum 25(OH)D (nm).

RESULTS

Prevalence of inadequate/insufficient vitamin D intake differed between dialysis modality, with 31% and 43% found to be insufficient (<50 nm) and 4% and 33% found to be deficient (<25 nm) in HD and PD patients, respectively (P < 0.001). In HD patients, there was a correlation between diet and supplemental vitamin D intake and 25(OH)D (ρ = 0.84, P < 0.001) and average sun exposure and 25(OH)D (ρ = 0.50, P < 0.02). There were no associations in PD patients. The results remained significant for vitamin D intake after multiple regression, adjusting for age, gender and sun exposure.

CONCLUSIONS

The results highlight a strong association between vitamin D intake and 25(OH)D in HD but not PD patients, with implications for replacement recommendations. The findings indicate that, even in a sunny climate, many dialysis patients are vitamin D deficient, highlighting the need for exploration of determinants and consequences.

The association between body mass index and mortality on peritoneal dialysis: a prospective cohort study

BACKGROUND

Previous studies have demonstrated that increased body mass index (BMI) is associated with decreased mortality in hemodialysis (HD) patients. However, the association between BMI and survival has not been well established in patients undergoing peritoneal dialysis (PD). The aim of the study was to determine the association between BMI and mortality in the PD population using the Clinical Research Center (CRC) registry for end-stage renal disease (ESRD) cohort in Korea.

METHODS

Prevalent patients with PD were selected from the CRC registry for ESRD, a prospective cohort study on dialysis patients in Korea. Patients were categorized into four groups by quartiles of BMI. Cox regression analysis was used to calculate the adjusted hazard ratio (HR) of mortality with a BMI of quartile 2 (21.4 - 23.5 kg/m(2)) as the reference.

RESULTS

A total of 900 prevalent patients undergoing PD were included. The median follow-up period was 24 months. The multivariate Cox proportional hazard model showed that the lowest quartile of BMI was associated with higher mortality (HR 3.00, 95% confidence interval (CI), 1.26 - 7.15). However, the higher quartiles of BMI were not associated with mortality compared with the reference category of BMI quartile 2 (Quartile 3: HR 1.11, 95% CI, 0.43 - 2.85, Quartile 4: HR 1.64, 95% CI, 0.66 - 4.06) after adjustment for clinical variables.

CONCLUSIONS

Lower BMI was a significant risk factor for death, but increased BMI was not associated with mortality in Korean PD patients.

Body mass index and mortality in patients on maintenance hemodialysis: a meta-analysis

PURPOSE

In patients undergoing maintenance hemodialysis (MHD), increasing numbers of studies have reported a reduced mortality in patients with an increased body mass index (BMI). This article provides a meta-analysis on the assessment of the relationship between BMI and mortality in MHD patients.

METHODS

A systemic literature review was conducted to identify studies that examined all-cause mortality, with or without cardiovascular events, on the basis of bodyweight or obesity measures in MHD population published before October 2012.

RESULTS

Eight observational studies with a total of 190,163 patients were included. Compared to the individuals with a normal BMI, overweight patients and obese patients were associated with lower all-cause mortality [relative risk (RR) 0.86, 95% confidence interval (CI) 0.84-0.88; RR 0.77, 95% CI 0.75-0.78, respectively] and cardiovascular mortality (RR 0.86; 95% CI 0.81-0.91; RR 0.78, 95% CI 0.73-0.83, respectively). Underweight patients had relatively higher all-cause and cardiovascular mortality (RR 1.22, 95% CI 1.20-1.25; RR 1.19, 95% CI 1.11-1.28, respectively). In an obesity-stratified analysis, the patients with moderate or severe obesity presented a strongly decreased all-cause mortality risk (RR 0.64, 95% CI 0.61-0.68) and cardiovascular mortality risk (RR 0.63, 95% CI 0.53-0.75) compared to patients with mild obesity (RR 0.74, 95% CI 0.71-0.77; RR 0.81, 95% CI 0.75-0.87, respectively).

CONCLUSIONS

These findings show that overweight and obese patients have lower all-cause and cardiovascular mortality rates in patients undergoing MHD. Body weight management and optimized nutritional and metabolic support should help to reduce the high mortality rates that are prevalent in the hemodialysis population.

Obesity and metabolic syndrome in kidney transplantation

The epidemic of obesity and metabolic syndrome (MS) contributes to the rapid growth of chronic kidney disease (CKD) and end-stage renal disease (ESRD). There is a reverse epidemiology, known as the "obesity paradox," in ESRD patients receiving maintenance dialysis. Obese patients are routinely referred for kidney transplant, and they have more surgical and medical complications than non-obese patients. However, compared to dialysis, kidney transplant provides a survival benefit for obese patients. After kidney transplant, obese patients tend to gain more body weight, and non-obese patients can develop new-onset obesity/MS. Obesity/MS is not only associated with serious morbidities, but also compromises the long-term graft and patient survival. The immunosuppressive drugs commonly used as maintenance therapy, including corticosteroids, calcineurin inhibitors and mammalian target-of-rapamycin inhibitors, contribute to obesity/MS. Development of novel immunosuppressive drugs free of metabolic adverse effects is needed, so that the full potential and benefits of kidney transplantation can be realized.

Influence of body mass index on the association of weight changes with mortality in hemodialysis patients

BACKGROUND AND OBJECTIVES

A high body mass index (BMI) is associated with lower mortality in patients undergoing hemodialysis. Short-term weight gains and losses are also related to lower and higher mortality risk, respectively. The implications of weight gain or loss may, however, differ between obese individuals and their nonobese counterparts.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

The Current Management of Secondary Hyperparathyroidism: A Multicenter Observational Study (COSMOS) is an observational study including 6797 European hemodialysis patients recruited between February 2005 and July 2007, with prospective data collection every 6 months for 3 years. Time-dependent Cox proportional hazard regressions assessed the effect of BMI and weight changes on mortality. Analyses were performed after patient stratification according to their starting BMI.

RESULTS

Among 6296 patients with complete data, 1643 died. At study entry, 42% of patients had a normal weight (BMI, 20-25 kg/m(2)), 11% were underweight, 31% were overweight, and 16% were obese (BMI ≥ 30 kg/m(2)). Weight loss or gain (<1% or >1% of body weight) was strongly associated with higher rates of mortality or survival, respectively. After stratification by BMI categories, this was true in nonobese categories and especially in underweight patients. In obese patients, however, the association between weight loss and mortality was attenuated (hazard ratio, 1.28 [95% confidence interval (CI), 0.74 to 2.14]), and no survival benefit of gaining weight was seen (hazard ratio, 0.98 [95% CI, 0.59 to 1.62]).

CONCLUSIONS

Assuming that these weight changes were unintentional, our study brings attention to rapid weight variations as a clinical sign of health monitoring in hemodialysis patients. In addition, a patient's BMI modifies the strength of the association between weight changes with mortality.

Changes in anthropometry and mortality in maintenance hemodialysis patients in the HEMO Study

BACKGROUND

Poor nutritional status has been associated with worse patient survival in maintenance hemodialysis patients. Anthropometric values are important nutritional measures, incorporating muscle and fat mass. However, the association of changes in anthropometry, including midarm circumference (MAC) and skinfold measurements, with mortality in hemodialysis patients remains unknown. Accordingly, we explored this association in the Hemodialysis (HEMO) Study.

STUDY DESIGN

Post hoc analysis of cohort data from a clinical trial.

SETTING & PARTICIPANTS

1,846 hemodialysis patients enrolled in the HEMO Study.

PREDICTORS

MAC and skinfold measurements.

OUTCOMES

Longitudinal changes in MAC and skinfolds were jointly modeled using repeated measures and survival modeling. Time-to-event outcomes were all-cause mortality, cardiac death and hospitalization, and infection-related death.

RESULTS

Mean MAC was 30.1 cm, and mean baseline sum of subscapular, biceps, and triceps skinfolds was 42.4 mm. During a median follow-up of 2.5 years, there were 845 deaths. During follow-up, MAC and the skinfold measurement declined 0.26 cm and 1.1 mm per year, respectively. Declines in MAC (per cm) and skinfold (per mm) measurements were associated with higher all-cause mortality (HRs of 1.58 [95% CI, 1.29-1.94; P < 0.001] and 1.06 [95% CI, 0.99-1.13; P = 0.09], respectively), poorer cardiac outcomes (HRs of 1.49 [95% CI, 1.23-1.81; P < 0.001] and 1.05 [95% CI, 0.99-1.10; P = 0.09], respectively), and higher infection-related hospitalization (HRs of 2.45 [95% CI, 1.55-3.88; P < 0.001] and 1.16 [95% CI, 0.98-1.37; P = 0.08], respectively). The association between declining MAC and skinfold with patient survival was most notable for those with body mass index (BMI) ≤25 kg/m2 (HRs of 2.41 [95% CI, 1.81-3.19; P < 0.001] and 1.22 [95% CI, 1.10-1.35; P < 0.001], respectively).

LIMITATIONS

Prevalent dialysis patients only, excluding individuals weighing >85 kg.

CONCLUSIONS

Declines in skinfold thickness were not associated significantly with outcomes except for participants with BMI ≤25 kg/m2. Declines in MAC are associated significantly with all-cause mortality and cardiac outcomes in hemodialysis patients, most notably in those with BMI ≤25 kg/m2.

Can new-onset diabetes after kidney transplant be prevented?

Because the negative consequences of new-onset diabetes mellitus after transplantation (NODAT) diminish the significant gains of kidney transplantation, it is imperative to develop clinical interventions to reduce the incidence of NODAT. In this review, we discuss whether intensive lifestyle interventions that delay or prevent type 2 diabetes mellitus may decrease the incidence of NODAT. We examine the literature pertaining to incidence and timing of onset of NODAT, as well as the risk factors and pathophysiology that NODAT shares with type 2 diabetes mellitus, namely pathways related to increased insulin resistance and decreased insulin secretion. Our central hypothesis is that NODAT results from the same metabolic risk factors that underlie type 2 diabetes mellitus. These risk factors are altered and enhanced by transplantation, "tipping" some transplant recipients with seemingly normal glucose homeostasis before transplant toward the development of NODAT. We describe the diabetogenic properties of transplant immunosuppressive drugs. We describe novel methods of prevention that are being explored, including resting the pancreatic β-cells by administration of basal insulin during the period immediately after transplant. On the basis of the current evidence, we propose that intensive lifestyle modification, adapted for individuals with chronic kidney disease or end-stage renal disease, as well as resting pancreatic β-cells during the immediate postoperative period, may lower the incidence of NODAT.

Mortality prediction by surrogates of body composition: an examination of the obesity paradox in hemodialysis patients using composite ranking score analysis

In hemodialysis patients, lower body mass index and weight loss have been associated with higher mortality rates, a phenomenon sometimes called the obesity paradox. This apparent paradox might be explained by loss of muscle mass. The authors thus examined the relation to mortality of changes in dry weight and changes in serum creatinine levels (a muscle-mass surrogate) in a cohort of 121,762 hemodialysis patients who were followed for up to 5 years (2001-2006). In addition to conventional regression analyses, the authors conducted a ranking analysis of joint effects in which the sums and differences of the percentiles of change for the 2 measures in each patient were used as the regressors. Concordant with previous body mass index observations, lower body mass, lower muscle mass, weight loss, and serum creatinine decline were associated with higher death rates. Among patients with a discordant change, persons whose weight declined but whose serum creatinine levels increased had lower death rates than did those whose weight increased but whose serum creatinine level declined. A decline in serum creatinine appeared to be a stronger predictor of mortality than did weight loss. Assuming residual selection bias and confounding were not large, the present results suggest that a considerable proportion of the obesity paradox in dialysis patients might be explained by the amount of decline in muscle mass.

Anthropomorphic measurements that include central fat distribution are more closely related with key risk factors than BMI in CKD stage 3

BACKGROUND

Body Mass Index (BMI) as a marker of obesity is an established risk factor for chronic kidney disease (CKD) and cardiovascular disease (CVD). However, BMI can overestimate obesity. Anthropomorphic measurements that include central fat deposition are emerging as a more important risk factor. We studied BMI, waist circumference (WC), waist-to-height ratio (WHtR), waist-to-hip ratio (WHR) and conicity index (CI) in a cohort of patients with CKD stage 3 and compared the associations with other known risk factors for CKD progression and CVD.

METHODS

1740 patients with CKD stage 3 were recruited from primary care for the Renal Risk in Derby study. Each participant underwent clinical assessment, including anthropomorphic measurements and pulse wave velocity (PWV), as well as urine and serum biochemistry tests.

RESULTS

The mean age of the cohort was 72.9±9 years with 60% females. The mean eGFR was 52.5±10.4 ml/min/1.73 m(2) and 16.9% of the cohort had diabetes. With the cohort divided into normal and increased risk of morbidity and mortality using each anthropomorphic measurement, those measurements that included increased central fat distribution were significantly associated with more risk factors for CKD progression and CVD than increased BMI. Univariable analysis demonstrated central fat distribution was correlated with more risk factors than BMI. Subgroup analyses using recognised BMI cut-offs to define obesity and quartiles of WHR and CI demonstrated that increasing central fat distribution was significantly associated with more CKD and CVD risk factors than increasing BMI.

CONCLUSION

Anthropomorphic measurements that include a measure of central fat deposition are related to more key risk factors in CKD stage 3 patients than BMI. Central fat deposition may be of greater importance as a risk factor in CKD than BMI and reliance on BMI alone may therefore underestimate the associated risk.

Obesity and mortality risk among younger dialysis patients

BACKGROUND AND OBJECTIVES

Many studies show that obesity in dialysis patients is not strongly associated with mortality but not whether this modest association is constant over age. This study investigated the extent to which the relation of body mass index (BMI) and mortality differs between younger and older dialysis patients.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Adult dialysis patients were prospectively followed from their first dialysis treatment for 7 years or until death or transplantation. Patients were stratified by age (<65 or ≥65 years) and baseline BMI (<20, 20-24 [reference], 25-29, and ≥30 kg/m(2)).

RESULTS

The study sample included 984 patients younger than 65 years and 765 patients 65 years or older; cumulative survival proportions at end of follow-up were 50% and 16%. Age-standardized mortality rate was 1.7 times higher in obese younger patients than those with normal BMI, corresponding to an excess rate of 5.2 deaths/100 patient-years. Mortality rates were almost equal between obese older patients and those with normal BMI. Excess rates of younger and older patients with low compared with normal BMI were 8.7 and 1.1 deaths/100 patient-years. After adjustment for age, sex, smoking, comorbidity, and treatment modality, hazard ratios by increasing BMI were 2.00, 1, 0.95, and 1.57 for younger patients and 1.07, 1, 0.88, and 0.91 for older patients, implying that obesity is a 1.7-fold (95% confidence interval, 1.1- to 2.9-fold) stronger risk factor in younger than older patients.

CONCLUSIONS

In contrast to older dialysis patients, younger patients with low or very high BMI had a substantially elevated risk for death.

Bariatric surgery and renal function

Obesity causes a significant healthcare burden and has been shown to be an important risk factor in the development of cardiovascular disease, type 2 diabetes, and increasingly chronic kidney disease. Bariatric surgery is the most effective treatment for obesity and has been shown to drastically improve both blood pressure and diabetic control. However, the interaction of bariatric surgery and renal function is less clear. This review focuses on the effect of bariatric surgery on renal function both in the acute situation, with respect to acute kidney injury, and also on changes in renal function parameters post-bariatric surgery weight loss. The interaction of obesity, bariatric surgery, and nephrolithiasis as a precipitant of acute kidney injury will also be considered. The role of bariatric surgery in pre- and post-renal transplant recipients is discussed as well as possible mechanisms underlying the improvement in renal function.

Blood pressure and survival in long-term hemodialysis patients with and without polycystic kidney disease

BACKGROUND

In maintenance dialysis patients, low blood pressure (BP) values are associated with higher death rates when compared with normal to moderately high values. This 'hypertension paradox' may be related to comorbid conditions. Dialysis patients with polycystic kidney disease (PKD) usually have a lower comorbidity burden and greater survival. We hypothesized that in PKD dialysis patients, a representative of a healthier dialysis patient population, high BP is associated with higher mortality.

METHODS

Time-dependent survival models including after multivariate adjustment were examined to assess the association between prehemodialysis and posthemodialysis BP and all-cause mortality in a 5-year cohort of 67 085 non-PKD and 1579 PKD hemodialysis patients.

RESULTS

In PKD patients, low prehemodialysis and posthemodialysis SBPs were associated with increased mortality, whereas high prehemodialysis DBP was associated with greater survival. Fully adjusted death hazard ratios (and 95% confidence levels) for prehemodialysis and posthemodialysis BP of less than 120 mmHg (reference 140 to <160 mmHg) were 1.30 (1.06-1.92) and 1.45 (1.04-2.02), respectively, and for prehemodialysis DBP of 80 mmHg or more (reference 70 to <80 mmHg) was 0.68 (0.49-0.93, all P values <0.05). Similar associations were observed in non-PKD patients. In pooled analyses, within each commensurate BP stratum, PKD patients exhibited superior survival to non-PKD patients.

CONCLUSION

Among hemodialysis patients, those with PKD display a similar BP paradox as those without PKD, even though within each BP category PKD patients maintain superior survival. Randomized clinical trials are needed to define optimal blood pressure targets in the hemodialysis population.

Abdominal obesity is the most significant metabolic syndrome component predictive of cardiovascular events in chronic hemodialysis patients

BACKGROUND

Five components of metabolic syndrome (MetS) have been identified as predictive of cardiovascular events (CVEs) in the general population: impaired fasting glucose, abdominal obesity, hypertriglyceridemia, hypertension and low high-density lipoprotein cholesterol. Whether MetS and its components are also predictive of CVEs in chronic hemodialysis (HD) patients remains unclear. We therefore investigated the role of MetS and its components in patients on chronic HD.

METHODS

MetS at baseline was diagnosed in 91 HD patients based on the American Heart Association/National Heart, Lung and Blood Institute (AHA/NHLBI) and the International Diabetes Federation (IDF) definitions. During a 3-year period, all hospitalizations, CVEs and deaths were recorded and analyzed using Kaplan-Meier survival analysis and Cox regression.

RESULTS

There were no differences in the number of CVEs, hospitalizations or deaths between patients with and without AHA/NHLBI-defined MetS; however, patients with IDF-defined MetS were found to be at a higher risk for CVEs (P = 0.006). Cox regression analysis showed that, of the MetS components, abdominal obesity was the single most significant predictor of CVEs (hazard ratio 6.25; 95% confidence interval: 1.65-23.6; P = 0.007).

CONCLUSIONS

IDF-defined MetS was more predictive of CVEs than AHA/NHLBI-defined MetS. Of the MetS components, abdominal obesity was the single most significant predictor of CVEs in chronic HD patients.

Unintentional weight loss is an independent predictor of mortality in a hemodialysis population

OBJECTIVE

This study investigated common components of classification of nutrition screening risk in the prediction of clinical end-points (mortality and morbidity) in hemodialysis patients over a 3-year period (2005 to 2008).

DESIGN

This was a retrospective cohort study.

SETTING

This study was conducted at a Hemodialysis centre.

PARTICIPANTS

The study included patients on maintenance hemodialysis in June 2005.

INTERVENTION

Assessment of nutrition risk was carried out using components of Protein-Energy Wasting criteria.

MAIN OUTCOME MEASURE

Clinical outcome at the 3-year follow-up (June 2008) was measured as mortality and morbidity (as unplanned hospital admissions). Risk of mortality was investigated independent of comorbidities, age, gender, ethnicity, and dialysis vintage using Cox proportional hazards model.

RESULTS

A total of 217 patients met the inclusion criteria (143 male [66%]; age, 60.5 ± 15.6 years). Patients who lost ≥5% body weight in the 6 months before the study commenced, had a 3-fold (Hazard Ratio = 3.0; 95% confidence interval: 1.2 to 7.5) independent greater risk of death (P = .02). Low serum albumin (<38 g/L) resulted in higher morbidity and mortality; however, this was not statistically significant when adjusted for confounders. Body mass index was only available in 64% (138 of 217) of the cohort at baseline, and was not related to clinical outcome at the 3-year follow-up.

CONCLUSION

Unintentional weight loss is independently predictive of clinical outcome in this cohort of dialysis patients. It is recommended that nutrition screening tools include weight loss as a key component in classification of risk and for prioritizing patient care.

The 'obesity paradox': a parsimonious explanation for relations among obesity, mortality rate and aging?

Objective

Current clinical guidelines and public health statements generically prescribe body mass index (BMI; kgm2) categories regardless of the individual’s situation (age, risk for diseases, etc.). However, regarding BMI and mortality rate (MR), two well-established observations are (1) there is a U-shaped (i.e., concave) association - people with intermediate BMIs tend to outlive people with higher or lower BMIs; and (2) the nadirs of these curves tend to increase monotonically with age. Multiple hypotheses have been advanced to explain either of these two observations. Here we introduce a new hypothesis that may explain both phenomena, by drawing on the so-called obesity paradox: the unexpected finding that obesity is often associated with increased survival time among people who have some serious injury or illness despite being associated with reduced survival time among the general population.

Results

We establish that the obesity paradox offers one potential explanation for two curious but consistently observed phenomena in the obesity field.

Conclusion

Further research is needed to determine the extent to which the obesity paradox is actually an explanation for these phenomena, but if our hypothesis proves true the common practice of prescribing overweight patients to lower their BMI should currently be applied with caution. In addition, the statistical modeling technique employed here could be applied in such other areas involving survival analysis of disjoint subgroups, in order to explain possible interacting causal associations and to determine clinical practice.

Key comorbid conditions that are predictive of survival among hemodialysis patients

BACKGROUND AND OBJECTIVES

Abstracting information about comorbid illnesses from the medical record can be time-consuming, particularly when a large number of conditions are under consideration. We sought to determine which conditions are most prognostic and whether comorbidity continues to contribute to a survival model once laboratory and clinical parameters have been accounted for.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Comorbidity data were abstracted from the medical records of Dialysis Outcomes and Practice Pattern Study (DOPPS) I, II, and III participants using a standardized questionnaire. Models that were composed of different combinations of comorbid conditions and case-mix factors were compared for explained variance (R(2)) and discrimination (c statistic).

RESULTS

Seventeen comorbid conditions account for 96% of the total explained variance that would result if 45 comorbidities that were expected to be predictive of survival were added to a demographics-adjusted survival model. These conditions together had more discriminatory power (c statistic 0.67) than age alone (0.63) or serum albumin (0.60) and were equivalent to a combination of routine laboratory and clinical parameters (0.67). The strength of association of the individual comorbidities lessened when laboratory/clinical parameters were added, but all remained significant. The total R(2) of a model adjusted for demographics and laboratory/clinical parameters increased from 0.13 to 0.17 upon addition of comorbidity.

CONCLUSIONS

A relatively small list of comorbid conditions provides equivalent discrimination and explained variance for survival as a more extensive characterization of comorbidity. Comorbidity adds to the survival model a modest amount of independent prognostic information that cannot be substituted by clinical/laboratory parameters.

Effect of icodextrin dialysis solution on body weight and fat accumulation over time in CAPD patients

BACKGROUND

The purpose of this study was to analyse the changes of body composition and the effects of icodextrin dialysis solution over time on peritoneal dialysis (PD) in continuous ambulatory peritoneal dialysis (CAPD) patients.

METHODS

Among 183 incident patients, 75 patients finished a complete 36-month protocol. Clinical indices including daily glucose absorption and body composition, by bioelectrical impedance analysis (BIA), were measured in both groups (icodextrin group: 36 patients, non-icodextrin group: 39 patients) at the 1st (baseline), 12th, 24th and 36th months.

RESULTS

There were significant increases in body weight and fat mass during the 36 months after initiation of CAPD. It was found that 78% of 3 years of weight gain occurred during the first year and 88% of weight gain at the end of the first year was fat mass gain. The icodextrin group showed a significantly lower percent of fat mass during the first 36 months (P < 0.05) and also less changes in body weight, fat mass, percent (%) fat mass, visceral fat area and waist/hip ratio at 1, 2 and 3 years than the non-icodextrin group. There were no significant changes in total body water (TBW), extra cellular fluid (ECF), oedema index and lean body mass (LBM) through comparable daily and ultrafiltration volume (UFV) between the two groups during the initial 3 years. Factors associated with the higher percent of fat mass gain over time on peritoneal dialysis were age, diabetes, gender (female) and non-icodextrin group (all, P < 0.01, generalized estimating equation).

CONCLUSION

The application of icodextrin solution may be a better option to alleviate excessive fat gain over time for patients on PD.

Nutritional and anti-inflammatory interventions in chronic heart failure

Currently, there are 5 million individuals with chronic heart failure (CHF) in the United States who have poor clinical outcomes, including high death rates. Observational studies have indicated a reverse epidemiology of traditional cardiovascular risk factors in CHF; in contrast to trends seen in the general population, obesity and hypercholesterolemia are associated with improved survival. The temporal discordance between the overnutrition (long-term killer) and undernutrition (short-term killer) not only can explain some of the observed paradoxes but also may indicate that malnutrition, inflammation, and oxidative stress may play a role that results in protein-energy wasting contributing to poor survival in CHF. Diminished appetite or anorexia and nutritional deficiencies may be both a cause and a consequence of this so-called malnutrition-inflammation-cachexia (MIC) or wasting syndrome in CHF. Neurohumoral activation, insulin resistance, cytokine activation, and survival selection-resultant genetic polymorphisms also may contribute to the prominent inflammatory and oxidative characteristics of this population. In patients with CHF and wasting, nutritional strategies including amino acid supplementation may represent a promising therapeutic approach, especially if the provision of additional amino acids, protein, and energy includes nutrients with anti-inflammatory and antioxidant properties. Regardless of the etiology of anorexia, appetite-stimulating agents, especially those with anti-inflammatory properties such as megesterol acetate or pentoxyphylline, may be appropriate adjuncts to dietary supplementation. Understanding the factors that modulate MIC and body wasting and their associations with clinical outcomes in CHF may lead to the development of nutritional strategies that alter the pathophysiology of CHF and improve outcomes.

Obesity as a predictor of vascular access outcomes: analysis of the USRDS DMMS Wave II study

Arteriovenous fistulae (AVF) are widely regarded as the preferred vascular access in hemodialysis patients due to their primary patency and patient survival benefits. While the obesity paradox has been associated with improved cardiovascular morbidity and all-cause mortality in dialysis patients, its long-term vascular access outcomes are less clear. Recent literature has suggested that obese patients may have increased early and late fistula failure. The purpose of this study was to explore the relationships between obesity and vascular access outcomes. We performed a retrospective cohort analysis using the USRDS DMMS Wave 2 data set. All incident dialysis patients as of January 1, 1996, over the age of 18, receiving only hemodialysis as mode of renal replacement therapy were eligible for inclusion. Among other variables, data collected for the DMMS Wave 2 included: type and location of vascular access, AVF maturity, vascular access revision, and failure. Logistic regression analyses were used to examine the relationships between obesity and vascular access outcomes, adjusting for important covariates. In all, 1486 hemodialysis patients were included. Using body mass index (BMI) <30 kg/m(2) as reference, obesity did not emerge as a factor in predicting vascular access revisions or failures. An increased risk of AVF failure to mature was found only in the highest BMI quartile (>or=35 kg/m(2)) (aOR 3.66 [95% CI 1.27-10.55], p = 0.017). Peripheral vascular disease was independently associated with an increased risk of AVF failure (aOR 2.78 [95% CI 1.01-7.63], p = 0.047) and arteriovenous graft (AVG) failure (aOR 1.65 [95% CI 1.03-2.64], p = 0.036). Obesity was not associated with increased AVF or AVG revision rates or failure and only associated with poorer AVF maturity at highest BMI quartile. We conclude that obesity should not preclude placement of AVF as vascular access of choice, except in the very obese where assessment should be individually based.