Body mass index for chronic hemodialysis patients: Stable hemodialysis and mortality

Body mass index (BMI) is used as a reference for weight control programs in the general population and in morbidity and mortality studies in diabetes patients. However, the implications of BMI in chronic hemodialysis patients is unclear. We studied the BMI of chronic hemodialysis patients, focusing on problems encountered during outpatient hemodialysis therapy and on 2-year mortality. Outpatients with chronic hemodialysis (n = 258; 144 men, 114 women) were divided into four groups: (i) patients with stable hemodialysis; (ii) patients with marked hypotension requiring catecholamine infusion during hemodialysis; (iii) patients with excessive interdialysis weight gain requiring occasional additional hemodialysis; and (iv) patients with troublesome hemodialysis due to other causes. The statistical differences between the average BMI among these groups were evaluated, and were subdivided into sex, age and the duration of hemodialysis history. The 2-year mortality rates of these patients were also studied according to their BMI. In patients under 60 years of age, those with excessive interdialysis weight gain had statistically larger BMI (23.2; n = 35) compared to patients with good hemodialysis control (20.1; n = 178), regardless of gender and hemodialysis history. The mortality rate was at a minimum at approximately 20 BMI in patients under 60 years of age. However, lower BMI was associated with a greater mortality rate in patients 60 years or over. For chronic hemodialysis patients, the BMI associated with stable hemodialysis and minimum mortality is approximately 20, in those under 60 years of age. The BMI of aged hemodialysis patients should be considered separately in morbidity and mortality studies.     

Body mass index and resistance to recombinant human erythropoietin therapy in maintenance hemodialysis patients

Abstract

The aim of this work was to contribute to a better understanding of the relationship between resistance to recombinant human erythropoietin (rhEPO) therapy and body mass index (BMI) in hemodialysis (HD) patients. We evaluated 191 HD patients and 25 healthy individuals. Complete blood count, reticulocyte count, and circulating levels of ferritin, transferrin, iron, soluble transferrin receptor (sTfR), transferrin saturation, hepcidin, C-reactive protein (CRP), interleukin 6 (IL-6), albumin, and adiponectin were measured in all patients and controls. Non-responder patients (n?=?16), as compared with responder patients (n?=?175), showed statistically significant lower BMI values, an enhanced inflammatory and higher adiponectin levels, associated with disturbances in iron metabolism. Analyzing the results according to BMI, we found that underweight patients required higher rhEPO doses than normal, overweight, and obese patients, and a higher percentage of non-responders patients were found within the underweight group of HD patients. Moreover, underweight patients presented lower levels of transferrin and higher levels of adiponectin compared to overweight and obese patients, and lower levels of iron compared with normal weight patients. Multiple regression analysis identified the sTfR, hemoglobin, BMI, and albumin as independent variables associated with rhEPO doses. In conclusion, our work showed that HD patients resistant to rhEPO therapy present a functional iron deficiency and a higher degree of inflammation, despite their lower BMI values and higher levels of adiponectin. Actually, BMI is poorly related with markers of systemic inflammation, such as IL-6 and CRP, while adiponectin works a fairly good indirect marker of adiposity within HD patients.     

Body weight-for-height relationships predict mortality in maintenance hemodialysis patients.

BACKGROUND: Protein-energy malnutrition is a strong predictor of mortality in maintenance hemodialysis (MHD) patients. This association has generally been described for serum chemistry measures of protein-energy malnutrition. We hypothesized that body weight-for-height relationships also predict survival in MHD patients. METHODS: During the last three months of 1993, data were obtained on 12,965 men and women concerning clinical characteristics (height, postdialysis weight, age, gender, race, and presence or absence of diabetes mellitus) and laboratory measurements (predialysis serum albumin, creatinine and cholesterol, and the urea reduction ratio). Patient survival during the next 12 months was evaluated retrospectively. RESULTS: In comparison to values for normal Americans determined from the National Health and Nutrition Evaluation Survey II data, weight-for-height relationships tended to be slightly lower than normal in African American men and women and Caucasian men undergoing MHD and were normal or slightly greater in the taller Caucasian women. In both men and women, the mortality rate decreased progressively as the patients' weight-for-height increased. MHD patients who weighed more than normal had the lowest mortality rates. After adjustment for clinical characteristics and laboratory measurements, the inverse relationship between mortality rates and weight-for-height percentiles was still highly significant for patients within the lower 50th percentile of body weight-for-height. Serum albumin correlated directly with weight-for-height in patients in the lower 50th percentile of weight-for-height. Serum creatinine and cholesterol correlated directly with weight-for-height in the entire population of men and women. In contrast, the urea reduction ratio was inversely correlated with weight-for-height. CONCLUSIONS: These data indicate that weight-for-height is a strong predictor of 12-month mortality in male and female MHD patients. Multivariate analyses indicate that body weight-for-height is an independent predictor of higher mortality in those patients who are in the lower 50th percentile for this measurement.     

Body mass index and cardiovascular risk factors and biomarkers in hemodialysis patients

BACKGROUND: Being overweight and obesity are associated with improved survival in hemodialysis (HD) patients, based on mechanisms that are presently uncertain. We compared traditional and uremia-related cardiovascular risk factors in HD patients stratified according to their body mass index (BMI). METHODS: One hundred sixteen HD patients were stratified into 4 groups according to the BMI: underweight (<18.5), normal weight (18.5-24.9), overweight (25.0-29.9) and obese (> or =30). Blood samples were obtained before the HD session to measure serum albumin, high-sensitivity C-reactive protein, fibrinogen, ferritin, total cholesterol, LDL cholesterol, HDL cholesterol, apolipoprotein A-I and apolipoprotein B-100, apolipoprotein B (apoB) to apolipoprotein A (apoA) ratio and Lp(a) lipoprotein. RESULTS: There were 3 underweight (excluded from the analysis), 58 normal weight, 35 overweight and 20 obese patients. Their mean age was 62.1 +/- 14.1 years. There were 68 men and 45 women. Mean dialytic age was 5.32 +/- 3.2 years. The mean BMI of the study population was 25.2 +/- 4.1. The prevalence of smoking habit was similar in the 3 groups (17.2%, 8.5% and 25%, respectively; p=0.28). The prevalence of hypertension was higher in overweight (77.1%) and obese (65%) patients than in leaner counterparts (53.4%), although the difference was not significant. Conversely, diabetes prevalence was significantly higher in overweight and obese patients (22.8% and 30%, respectively) than in normal weight patients (6.9%; p=0.02). The serum levels of total cholesterol, HDL cholesterol, LDL cholesterol, Lp(a) lipoprotein, apolipoprotein A-I, apolipoprotein B-100, and apoA/apoB ratio were similar in the 3 BMI groups. Triglycerides levels were significantly higher in obese (221.2 +/- 132.7 mg/dL) and overweight (230.5 +/- 119.3 mg/dL) patients than in those of normal weight (154.6 +/- 78.8 mg/dL; p=0.02). Most of the uremia-related cardiovascular risk factors (anemia, hyperparathyroidism, chronic inflammation) were comparable among BMI categories as well as the levels of C-reactive protein, fibrinogen and ferritin. CONCLUSION: The present study suggests that almost all traditional and uremia-related cardiovascular risk factors do not differ significantly among different categories of BMI in hemodialysis patients.     

Body mass index as a predictor of fracture risk: A meta-analysis

Low body mass index (BMI) is a well-documented risk factor for future fracture. The aim of this study was to quantify this effect and to explore the association of BMI with fracture risk in relation to age, gender and bone mineral density (BMD) from an international perspective using worldwide data. We studied individual participant data from almost 60,000 men and women from 12 prospective population-based cohorts comprising Rotterdam, EVOS/EPOS, CaMos, Rochester, Sheffield, Dubbo, EPIDOS, OFELY, Kuopio, Hiroshima, and two cohorts from Gothenburg, with a total follow-up of over 250,000 person years. The effects of BMI, BMD, age and gender on the risk of any fracture, any osteoporotic fracture, and hip fracture alone was examined using a Poisson regression model in each cohort separately. The results of the different studies were then merged. Without information on BMD, the age-adjusted risk for any type of fracture increased significantly with lower BMI. Overall, the risk ratio (RR) per unit higher BMI was 0.98 (95% confidence interval [CI], 0.97–0.99) for any fracture, 0.97 (95% CI, 0.96–0.98) for osteoporotic fracture and 0.93 (95% CI, 0.91–0.94) for hip fracture (all p <0.001). The RR per unit change in BMI was very similar in men and women ( p >0.30). After adjusting for BMD, these RR became 1 for any fracture or osteoporotic fracture and 0.98 for hip fracture (significant in women). The gradient of fracture risk without adjustment for BMD was not linearly distributed across values for BMI. Instead, the contribution to fracture risk was much more marked at low values of BMI than at values above the median. This nonlinear relation of risk with BMI was most evident for hip fracture risk. When compared with a BMI of 25 kg/m², a BMI of 20 kg/m² was associated with a nearly twofold increase in risk ratio (RR=1.95; 95% CI, 1.71–2.22) for hip fracture. In contrast, a BMI of 30 kg/m², when compared with a BMI of 25 kg/m², was associated with only a 17% reduction in hip fracture risk (RR=0.83; 95% CI, 0.69–0.99). We conclude that low BMI confers a risk of substantial importance for all fractures that is largely independent of age and sex, but dependent on BMD. The significance of BMI as a risk factor varies according to the level of BMI. Its validation on an international basis permits the use of this risk factor in case-finding strategies.     

维持性血液透析患者外周动脉疾病与全因死亡的相关性

目的 通过测量踝肱指数（ABI）调查维持性血液透析（MHD）患者下肢外周动脉疾病（PAD）,观察其与透析患者全因死亡的关系.方法 纳入四川省人民医院血液净化中心177例MHD患者,收集其一般资料、透析前血压、实验室检查结果,并测量ABI.以任何一侧ABI＜0.90作为下肢动脉缺血的诊断标准,随访29个月,采用Kaplan-Meier及Cox回归分析下肢动脉疾病与患者全因死亡的关系.结果 下肢缺血PAD的患病率为12.5％ （22/177）,PAD组患者年龄较高[（67±16）岁比（58± 15）岁,P=0.017].Kaplan-Meier分析提示,PAD组患者生存率低于无PAD组（P＜0.001）;Cox分析显示,校正年龄、性别、透析龄、糖尿病、冠心病之后,PAD患者死亡风险是无PAD患者的3.39倍（95％可信区间1.44～7.97,P=0.005）,糖尿病（风险比=2.917,95％可信区间1.280～6.649,P=0.011）和年龄（风险比=1.042,95％可信区间1.007～ 1.077,P=0.018）也是该人群死亡的危险因素.结论 MHD患者外周血管疾病患病率较高,PAD、糖尿病和年龄是MHD患者死亡的独立危险因素.     

Impact of hemoglobin variability on cardiovascular mortality in maintenance hemodialysis patients

International Urology and Nephrology - Although the association between anemia and cardiovascular mortality in hemodialysis patients is well established, whether hemoglobin variability (Hgb-Var)...     

Inflammation and inverse associations of body mass index and serum creatinine with mortality in hemodialysis patients.

OBJECTIVE: Protein-energy wasting and inflammation are common and associated with an increased risk of mortality in hemodialysis (HD) patients. We examined the extent to which they mediate the associations of each other with death in this population. STUDY DESIGN: Retrospective analysis of the Hemodialysis (HEMO) Study data. SETTING: Prevalent HD patients. PARTICIPANTS: One-thousand HEMO study participants with data available on C-reactive protein (CRP), body mass index (BMI), and serum creatinine. INTERVENTION: None. MAIN OUTCOME MEASURE: The associations of CRP, BMI, and serum creatinine with time to all-cause mortality separately and together in multivariate Cox models. RESULTS: In 1,437 patient-years of follow-up, there were 265 (26.5%) all-cause deaths. Compared with the lowest CRP quartile, the highest quartile was associated with a hazard ratio (HR) of 2.02 (95% confidence interval [CI], 1.31-3.10) for all-cause mortality. This association of highest CRP quartile with mortality was not attenuated with further adjustment for BMI and serum creatinine (HR, 2.13; 95% CI, 1.38-3.30). When serum albumin was added to the model, the hazard of death associated with highest CRP quartile was modestly attenuated (HR, 1.88; 95% CI, 1.21-2.92). In contrast, both BMI (for each kg/m2 increase; HR, 0.94; 95% CI, 0.91-0.96 for all-cause mortality) and serum creatinine (for each mg/dL increase; HR, 0.85; 95% CI, 0.79-0.90 for all-cause mortality) had strong, independent protective effects. Further adjustment with CRP had a negligible effect on these associations. CONCLUSION: The associations of markers of nutrition and inflammation with mortality are largely independent of each other in HD patients.     

Serum alkaline phosphatase predicts mortality among maintenance hemodialysis patients

Several observational studies have demonstrated that serum levels of minerals and parathyroid hormone (PTH) have U- or J-shaped associations with mortality in maintenance hemodialysis patients, but the relationship between serum alkaline phosphatase (AlkPhos) and risk for all-cause or cardiovascular death is unknown. In this study, a 3-yr cohort of 73,960 hemodialysis patients in DaVita outpatient dialysis were studied, and the hazard ratios for all-cause and cardiovascular death were higher across 20-U/L increments of AlkPhos, including within the various strata of intact PTH and serum aspartate aminotransferase. In the fully adjusted model, which accounted for demographics, comorbidity, surrogates of malnutrition and inflammation, minerals, PTH, and aspartate aminotransferase, AlkPhos > or =120 U/L was associated with a hazard ratio for death of 1.25 (95% confidence interval 1.21 to 1.29; P < 0.001). This association remained among diverse subgroups of hemodialysis patients, including those positive for hepatitis C antibody. A rise in AlkPhos by 10 U/L during the first 6 mo was incrementally associated with increased risk for death during the subsequent 2.5 yr. In summary, high levels of serum AlkPhos, especially >120 U/L, are associated with mortality among hemodialysis patients. Prospective controlled trials will be necessary to test whether serum AlkPhos measurements could be used to improve the management of renal osteodystrophy.     

Body fat mass and lean mass as predictors of survival in hemodialysis patients

A higher body mass index (BMI) is a predictor of better survival in hemodialysis patients, although the relative importance of body fat and lean mass has not been examined in the dialysis population. We performed an observational cohort study in 808 patients with end-stage renal disease on maintenance hemodialysis. At baseline, fat mass was measured by dual-energy X-ray absorptiometry and expressed as fat mass index (FMI; kg/m2). Lean mass index (LMI) was defined as BMI minus FMI. During the mean follow-up period of 53 months, 147 deaths, including 62 cardiovascular (CV) and 85 non-CV fatal events, were recorded. In univariate analysis, LMI was not significantly associated with CV or non-CV death, whereas a higher FMI was predictive of lower risk for non-CV death. Analyses with multivariate Cox models, which took other confounding variables as covariates, indicated the independent associations between a higher LMI and a lower risk of CV death, as well as between a higher FMI and a lower risk of non-CV death. These results indicate that increased fat mass and lean mass were both conditions associated with better outcomes in the dialysis population.     

维持性血液透析患者踝臂指数测定的临床意义

目的探讨维持性血液透析（MHD）患者踝臂指数（ABI）与微炎症状态的关系。方法选择我院血液透析中心MHD患者53例,根据其ABI值分为2组：正常ABI组（ABI≥0．9）32例,低ABI组（ABI〈0．9）21例,比较2组患者的血压、血脂、肾功能、血清白蛋白（Alb）、超敏C反应蛋白（hs—CRP）、白细胞介素（IL）-6、肿瘤坏死因子α（TNF-α）,并将ABI与年龄、hs—CRP、IL-6、TNF-α进行相关性分析。结果①2组患者血压、血脂、肾功能无统计学差异（P〉0．05）,低ABI组Alb低于正常ABI组,差异有统计学意义（P〈0．01）;②低ABI组hs-CRP、IL-6、TNF-α高于正常ABI组,差异有统计学意义（P〈0．05或P〈0．01）;③相关性分析显示,ABI与年龄、hs-CRP、IL-6、TNF-α呈负相关（r分别为-0．423、-0．531、-0．406、-0．466,P〈0．01）,与Alb呈正相关（r=0．451,P〈0．01）。结论踝臂指数降低预示体内存在微炎症状态。     

Initial body mass indexes have contrary effects on change in body weight and mortality of patients on maintenance hemodialysis treatment.

Malnutrition is a relevant risk factor for mortality for patients on maintenance hemodialysis treatment. In a retrospective study including 377 patients who began hemodialysis treatment between 1986 and 2001, we assessed the prevalence of different statuses of nutrition and the impact of the initial status of nutrition on the change in body weight and patient survival. We found an inverse relationship between body mass index (BMI, kg/m2) and the gain in body weight and BMI within 12 months of hemodialysis treatment. Underweight and normal weight patients had a substantial increase in these parameters, greatest in underweight subjects, whereas overweight and obese patients showed only a moderate increase or none (P =.0019, P =.00036). Adjusted mortality rates showed an inverse correlation with the initial BMI (P <.0001). There was a statistically significant difference in the mortality between patients with normal weight and overweight or obesity, respectively, showing a more favorable prognosis in overweight and obese patients (P =.0007; P =.022; log-rank, normal versus overweight, P =.012). Weight loss was the greatest independent risk factor for mortality in general. Adjusted hazard ratio of death was highest in underweight patients (3.999; CI, 2.708 to 5.905; P <.0001) and decreased to 2.251 (CI, 1.795 to 2.822; P <.0001) in normal weight, 1.927 (CI, 1.390 to 2.670; P <.0001) in overweight, and 1.651 (CI, 0.841 to 3.236; P =.1439) in obese subjects when patients with weight loss were compared with patients who preserved their initial weight or gained weight. Overall, the initial BMI has an influence on the change in body weight as well as on patient survival in general and in the case of weight loss in particular.     

Predialysis blood pressure and mortality risk in a national sample of maintenance hemodialysis patients.

The role of predialysis blood pressure (BP) as a risk factor for the high mortality in chronic hemodialysis (HD) patients has remained controversial. The objective of the current study was to further explore in a national random sample of 4,499 US hemodialysis patients any relationship of systolic or diastolic and predialysis or postdialysis BP with mortality, while considering subgroups of patients and controlling for other patient characteristics and comorbidities. The main finding of this study is the association of a low predialysis systolic BP with an elevated adjusted mortality risk (relative mortality risk [RR] = 1.86 for systolic BP < 110, P < 0.0001). No association with an elevated mortality risk could be observed for predialysis systolic hypertension (RR = 0.98 to 0.99, not significant [NS]), except for an elevated risk of cerebrovascular deaths. Postdialysis systolic BP was associated with an elevated mortality risk both for low and high BP levels as compared with midrange BP. Further evaluation of the elevated mortality risk associated with low predialysis systolic BP indicated similar patterns for both diabetic and nondiabetic subgroups and for patients with and without congestive heart failure (CHF) or coronary artery disease, although it was more pronounced among those with CHF. The level of predialysis fluid excess did not modify these results substantially. The findings from this historical prospective national study do not argue against the treatment of hypertension and suggest greater attention to postdialysis hypertension. The strikingly elevated mortality risk with low predialysis systolic BP suggests that low predialysis BP needs to be viewed with great concern and avoided where possible.     

Infective spondylodiscitis in patients on maintenance hemodialysis: a case series

Infective spondylodiscitis is a rare disease. This case review describes the clinical course, risk factors, and outcomes of adult patients on maintenance hemodialysis who presented with infective spondylodiscitis at a single medical center in Taiwan. There were 18 cases (mean age: 64.9?±?10.8 years) over more than 10 years. Analysis of underlying diseases indicated that 50% of patients had diabetes, 55.6% had hypertension, 55.6% had coronary artery disease, 22.2% had congestive heart failure, 22.2% had a cerebral vascular accident, 16.7% had liver cirrhosis, and 11.1% had malignancies. Sixty-one percent of patients had a degenerative spinal disease and the most common symptom was back pain (83.3%). A total of 38.9% of patients had leukocytosis, 99.4% had elevated levels of C-reactive protein, 78.6% had elevated erythrocyte sedimentation rates, and 55.6% had elevated levels of alkaline phosphatase. The average hemodialysis duration was 72.8?±?87.5 months, and 8 patients (44.4%) started hemodialysis within 1 year prior to infective spondylodiscitis. Four patients (22.2%) had vascular access infection-associated spondylodiscitis. The lumbar region was the most common location of infection (77.8%), 44.4% of patients developed abscesses, and Staphylococci were the most common pathogen (38.9%). The mortality rate was 16.7%, all due to sepsis. Thirty-three percent of the survivors had recurrent infective spondylodiscitis within 1 year. Infective spondylodiscitis should be considered in hemodialysis patients who present with prolonged back pain with or without fever. Non-contrast MRI is an appropriate diagnostic tool for this condition. Vascular access infection increases the risk for infective spondylodiscitis in hemodialysis patients.