Increased body mass index is not a reliable marker of good nutrition in hemodialysis patients

OBJECTIVE: The aim of the study was to assess the body fat (BF) composition in hemodialysis (HD) patients using anthropometry and bioelectrical impedance analysis (BIA) and investigate relationships between BIA-determined BF composition and nutritional parameters in different weight groupings. DESIGN: Cross-sectional study. SETTING: A tertiary-care university hospital. METHODS: 164 HD patients (M/F: 89/75, mean age: 48.4 +/- 15.8 years, mean HD duration: 58.2 +/- 42.6 months) were divided into three groups according to body mass index (BMI): normal weight (NW: BMI 18.5-24.9), overweight (OW: BMI 25-29.9), obese (OB, BMI > or = 30). Biochemical parameters and BF composition using anthropometry and foot-to-foot BIA were compared between three groups. RESULTS: Ninety-six (59%) patients were NW, 40 (24%) were OW, and 28 (17%) were OB. Average mean skinfold thickness (p = 0.005), mid-arm circumference (p = 0.001), BF% (p = 0.001), and fat-free mass (FFM) (p = 0.03) were all significantly greater in the OB group than in the NW group. Compared to the NW patients, the OB group had significantly higher serum levels of glucose (p = 0.03), total cholesterol (p = 0.02), and triglycerides (p = 0.02), but significantly lower serum albumin (p = 0.05) and blood urea nitrogen (p = 0.05). The OB group also had significantly higher white blood cell count (p = 0.002) and serum CRP (p = 0.001) than the NW group. CONCLUSIONS: The results suggest that BIA-determined BF composition is correlated with body mass index. In addition, obesity is associated with elevated CRP and white blood cell count and lower serum albumin level in HD patients.     

Near infra-red interactance for nutritional assessment of dialysis patients.

BACKGROUND: Malnutrition is a common problem in dialysis patients and may affect up to one-third of patients. Near-infrared interactance (NIR) is a novel approach to estimate body composition and per cent total body fat. METHODS: We used near-infrared interactance (Futrex 5000) to estimate the body composition including body fat percentage, as well as subjective global assessment (SGA), anthropometric measurements including mid-arm circumference (MAC), triceps and biceps skinfold thickness, calculated mid-arm muscle circumference (MAMC), body mass index (BMI), and laboratory values. NIR score, SGA assessment and anthropometric parameters were measured shortly after the end of a dialysis session. NIR measurement was made by placing a Futrex sensor on the nonaccess upper arm for several seconds. Serum albumin, transferrin (reflected by total iron binding capacity), and total cholesterol concentrations were performed as well. RESULTS: Thirty-four patients (20 men and 14 women) were selected from a pool of 120 haemodialysis patients. Their ages ranged from 26 to 86 years (58+/-14 years). Time on dialysis ranged from 8 months to 19 years (4.5+/-4.6 years). NIR scores were significantly different in three SGA groups: (A) well-nourished, 32.5+/-6.9%; (B) mildly to moderately malnourished, 29.2+/-5.3%; and (C) severely malnourished, 23.2+/-10.2% (P<0.001). Pearson correlation coefficients (r) between the NIR score and nutritionally relevant parameters were significant (P<0.001) for body mass index (r=+0.81), mid-arm circumference (r=+0.74), triceps skin fold (r=+0.54), biceps skin fold (r=+0.55), and mid-arm muscle circumference (r=+0.54). An inverse correlation was also found between NIR and years dialysed (r=-0.49, P=0.004), denoting a lesser body fat percentage according to NIR for patients dialysed longer. NIR was correlated with serum transferrin (r=+0.41, P=0.016) and cholesterol (r=+0.39, P=0.022) and marginally with serum albumin (r=+0.29, P=0.097). CONCLUSIONS: We conclude that NIR, which can be performed within seconds, may serve as an objective indicator of nutritional status in haemodialysis patients. More comparative and longitudinal studies are needed to confirm the validity of NIR measurements in nutritional evaluation of dialysis patients.     

The influence of gender, weight, height and BMI on pentosidine concentrations in plasma of hemodialyzed patients

BACKGROUND/AIMS: Advanced glycation end-products (AGEs) such as pentosidine play an important role in complications associated with chronic renal failure (CRF) and hemodialysis (HD). This study was undertaken to determine the influence of anthropometric parameters and inflammation on plasma pentosidine concentrations. METHODS: We measured total and free pentosidine in the plasma of 49 patients on chronic HD. Acid hydrolysis of plasma and protein precipitation with trichloroacetic acid was done in the case of total and free pentosidine, respectively. Pentosidine was measured by high performance liquid chromatography (HPLC). C-reactive protein (CRP) was measured by the nephelometric method. RESULTS: A strong negative correlation between dry weight and mean concentration of total pentosidine before and after HD was found (R = -0.47, p < 0.001). This correlation was stronger in males (R = -0.47, p = 0.017) than females (R = -0.34, p = 0.10). Even stronger correlations were noted between body mass index (BMI) and total (R = -0.55, p < 0.001), as well as free (R = -0.39, p = 0.01) pentosidine. Multivariate analysis demonstrated that BMI and time on HD were two independent factors influencing total pentosidine concentrations. CRP did not correlate with pentosidine or BMI. CONCLUSIONS: Lower BMI values are associated with significantly higher plasma pentosidine concentrations in patients on HD. Presumably this relationship is mediated by hypercatabolism observed in these patients. Catabolism produces weight loss and reduces BMI concurrently with the induction of oxidative and carbonyl stresses that stimulate the generation of pentosidine and other harmful AGEs in dialyzed patients.     

Increased subcutaneous insulin requirements in diabetic patients recently commenced on peritoneal dialysis.

BACKGROUND: Diabetic patients often have reduced insulin requirements when they progress to renal failure. Since peritoneal dialysis (PD) solution contains glucose, the insulin requirement of these patients often increases after commenced on PD. However, the change in insulin requirement has not been studied systematically. METHODS: We study 60 consecutive patients (32 male) with diabetic nephropathy newly started on PD. Their insulin requirement before and 6 months after initiation of dialysis is compared. Clinical factors affecting insulin requirement are explored. RESULTS: All patients received a standard 6 l/day dialysis exchange. The mean age was 60.3 +/- 8.9 years. Twelve patients did not require insulin before PD; four of them were started on insulin 6 months after dialysis. The average dosages of insulin 6 months before and after PD were 0.27 +/- 0.28 and 0.37 +/- 0.29 unit/kg/day, respectively (paired t-test, P < 0.001). The increment in dosage was 0.103 +/- 0.216 unit/kg/day. The dosage of insulin requirement correlates with the small solute transport of the peritoneal membrane, as represented by the mass transfer area coefficient (MTAC) of creatinine (r = -0.307, P = 0.017) and haemoglobin level (r = 0.284, P = 0.028), but not with body mass index (BMI). The change in insulin dosage correlates with the number of 2.5% dialysis cycle required per day (r = 0.433, P = 0.001), but not with peritoneal transport status or BMI. In patients who did not receive hypertonic exchange, the dosage of insulin increased by 1.5 +/- 11.1 unit/day. Each extra 2.5% 2 l exchange results in a 7.5 unit/day (95%CI 3.2-11.8, P = 0.001) increase in insulin requirement. CONCLUSION: Diabetic patients have a minimal increase in insulin requirement after initiation of PD per se, but the dosage of insulin increased markedly after exposure to hypertonic glucose solution. Our result provides a basis for the dosage adjustment of insulin in diabetic patients newly commenced on PD.     

Atherosclerosis in haemodialysis patients without significant comorbidities: determinants of progression

AIM: The aim of this prospective study was to assess the determinants of the progression of carotid artery intima-media thickness (CA-IMT) for 1 year in haemodialysis (HD) patients without significant comorbidities. METHODS: Fifty-four HD patients younger than 55 years, without diabetes, obesity and any clinical evidence of cardiovascular disease (29 men, 25 women; mean age 33.3 +/- 10 years; mean time on HD 49.4 +/- 43 months) were included in the 1-year study. CA-IMT was assessed at baseline and after 12 months. The difference in IMT between these two points of time was calculated (DeltaCA-IMT). C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), haematocrit-corrected ESR, beta-2 microglobulin, cardiac troponin I, lipid profile, fibrinogen, homocysteine, CaXP product, intact parathyroid hormone, haematocrit, albumin, uric acid levels, anthropometric parameters (age, body mass index), smoking, hypertension and left ventricular hypertrophy were recorded at baseline. RESULTS: The mean value for CA-IMT at baseline (0.59 +/- 0.05 mm) was significantly lower than that at 12 months (0.64 +/- 0.07 mm) (P < 0.001). CA-IMT had increased in 41 patients (75.9%). Age (P = 0.02), CRP (P = 0.03), beta-2 microglobulin (P = 0.001) and left ventricular hypertrophy (P = 0.01) were independently related with CA-IMT at baseline. Age (P = 0.003) and CRP (P = 0.04) were the independent variables related with CA-IMT, measured at 12 months. DeltaCA-IMT correlated positively with age (r = 0.31, P < 0.05). Age and sex were independent predictors of DeltaCA-IMT (R(2) for the model 0.56). CONCLUSION: In addition to age and male sex, non-specific inflammation may have a possible role in the progression of atherosclerosis in HD patients without significant comorbidities.     

The prognostic impact of fluctuating levels of C-reactive protein in Brazilian haemodialysis patients: a prospective study.

BACKGROUND: A single elevated C-reactive protein (CRP) value predicts mortality in haemodialysis (HD) patients, but the relative importance of repeated vs occasional positive systemic inflammatory response findings is not known. METHODS: To assess the influence on survival of occasional inflammation, CRP, serum albumin (S-Alb) and fibrinogen were analysed bimonthly in 180 HD patients (54% male, 49+/-14 years). Clinically significant inflammation was defined as CRP >5.1 mg/l, based on the receiver operating characteristics curve for CRP as predictor of death. Based on four consecutive measurements of CRP, patients were assigned into three groups: group 1 (n = 74; 41%), no inflammation (CRP < or = 5.1 mg/l in all measurements); group 2 (n = 65; 36%), occasional inflammation (1-3 measurements of CRP > 5.1 mg/l); and group 3 (n = 41; 23%), persistent inflammation (all measurements of CRP >5.1 mg/l). The nutritional status was evaluated by subjective global assessment (SGA) and body mass index (BMI), and the survival (21 months of follow-up) by Kaplan-Meier curve and Cox model. RESULTS: The median and range of CRP values (mg/l) for group 1, 2 and 3 were: 3.2 (3.2-5.1), 3.6 (3.2-54.9) and 13.8 (5.2-82), respectively (P<0.001), whereas the prevalence of malnutrition, assessed by SGA and BMI, did not differ significantly between the groups. The survival rate by Kaplan-Meier analysis was significantly different among the groups (chi2 = 12.34; P = 0.0004). Patients in group 3 showed the highest mortality (34%; P = 0.001), compared with group 1 (8%) and group 2 (14%; P = 0.01), respectively, whereas there was no significant difference in mortality between groups 1 and 2. Age, CRP, S-Alb level and SGA were independent predictors of mortality. CONCLUSION: The patients with a persistent elevation of CRP had a higher mortality rate than the patients with occasional CRP elevation. Thus, persistent, rather than occasional, inflammation is an important predictor of death in HD patients.     

Nutritional-inflammation status and resistance to erythropoietin therapy in haemodialysis patients.

BACKGROUND: Chronic kidney disease patients who are resistant to erythropoietin (EPO) treatment may suffer from malnutrition and/or inflammation. METHODS: In a cross-sectional study of haemodialysis patients, we investigated the relationship between the natural logarithm of the weekly EPO dose normalized for post-dialysis body weight and outcome measures of nutrition and/or inflammation [BMI, albumin and C reactive protein (CRP)] by means of multiple linear regression analysis. On the basis of the decile distribution of weekly EPO doses, we also evaluated four groups of patients: untreated, hyper-responders, normo-responders and hypo-responders. RESULTS: Six hundred and seventy-seven adult haemodialysis patients were recruited from five Italian centres. BMI and albumin were lower in the hypo-responders than in the other groups (21.3+/-3.8 vs 24.4+/-4.7 kg/m(2), P<0.001; and 3.8+/-0.6 vs 4.1+/-0.4 g/dl, P<0.001), whereas the median CRP level was higher (1.9 vs 0.8 mg/dl, P = 0.004). The median weekly EPO dose ranged from 30 IU/kg/week in the hyper-responsive group to 263 IU/kg/week in the hypo-responsive group. Transferrin saturation linearly decreased from the hyper- to hypo-responsive group (37+/-15 to 25+/-10%, P = 0.003), without any differences in transferrin levels. Ferritin levels were lower in the hypo-responsive than in the other patients (median 318 vs 445 ng/ml, P = 0.01). At multiple linear regression analysis, haemoglobin, BMI, albumin, CRP and serum iron levels were independently associated with the natural logarithm of the weekly EPO dose (R(2) = 0.22). CONCLUSIONS: Our findings support a clear association between EPO responsiveness and nutritional and inflammation variables in haemodialysis patients; iron deficiency is still a major cause of hypo-responsiveness.     

Must metabolic acidosis be associated with malnutrition in haemodialysed patients?

BACKGROUND: Metabolic acidosis was evaluated in the past as an independent variable of catabolism in haemodialysis (HD) patients. Nevertheless, it could in theory reflect a higher acid production from protein oxidation. The aim of this study was to evaluate the incidence and basis of metabolic acidosis in conjunction with a nutritional assessment in a HD population (n=120). METHODS: Three groups were identified based on three consecutive monthly predialysis plasma bicarbonate concentrations (P(HCO3)) and pH values. The effect of correction of metabolic acidosis on nutritional parameters was also studied in acidotic patients. RESULTS: The mean P(HCO3) ranged from 19.2+/- 0.4 mmol/l in group A (n=21) to 24.4+/-0.3 mmol/l in group B (n=80) and 27.5+/-0.4 mmol/l in group C (n=19). The adequency of dialysis (Kt/V) and ultrafiltration rates was comparable in the three groups. When compared with group B, group A had significantly higher body mass index (BMI), triceps skin fold thickness (TSF), dietary protein intake (DPI), normalized protein catabolic rate (nPCR) as well as serum creatinine, K(+) and intact parathyroid hormone (I-PTH). In contrast, when compared with group B, group C had a significantly lower DPI, nPCR, plasma creatinine and albumin. There was no significant difference in plasma inflammatory markers such as C-reactive protein (CRP) and interleukin 6 (IL-6) among all three groups. There was a significant negative correlation between P(HCO3) and nPCR (P<0.001), DPI (P<0.001), creatinine (P<0.001). Over a period of 6 months, the correction of metabolic acidosis in the HD patients did not affect nutritional parameters. CONCLUSION: These findings suggest that metabolic acidosis as a result of a higher protein intake does not detrimentally affect nutritional status.     

Increased Body Mass Index Is Not a Reliable Marker of Good Nutrition in Hemodialysis Patients

Objective. The aim of the study was to assess the body fat (BF) composition in hemodialysis (HD) patients using anthropometry and bioelectrical impedance analysis (BIA) and investigate relationships between BIA-determined BF composition and nutritional parameters in different weight groupings. Design. Cross-sectional study. Setting. A tertiary-care university hospital. Methods. 164 HD patients (M/F: 89/75, mean age: 48.4 ± 15.8 years, mean HD duration: 58.2 ± 42.6 months) were divided into three groups according to body mass index (BMI): normal weight (NW: BMI 18.5–24.9), overweight (OW: BMI 25–29.9), obese (OB, BMI ≥ 30). Biochemical parameters and BF composition using anthropometry and foot-to-foot BIA were compared between three groups. Results. Ninety-six (59%) patients were NW, 40 (24%) were OW, and 28 (17%) were OB. Average mean skinfold thickness (p = 0.005), mid-arm circumference (p = 0.001), BF% (p = 0.001), and fat-free mass (FFM) (p = 0.03) were all significantly greater in the OB group than in the NW group. Compared to the NW patients, the OB group had significantly higher serum levels of glucose (p = 0.03), total cholesterol (p = 0.02), and triglycerides (p = 0.02), but significantly lower serum albumin (p = 0.05) and blood urea nitrogen (p = 0.05). The OB group also had significantly higher white blood cell count (p?=?0.002) and serum CRP (p = 0.001) than the NW group. Conclusions. The results suggest that BIA-determined BF composition is correlated with body mass index. In addition, obesity is associated with elevated CRP and white blood cell count and lower serum albumin level in HD patients.     

Changes in common carotid artery intima-media thickness over 1 year in patients on peritoneal dialysis.

BACKGROUND: Accelerated atherosclerosis and vascular calcifications increase cardiovascular morbidity and mortality in patients on dialysis. Common carotid artery (CCA) intima-media thickness (IMT) is considered useful for imaging atherosclerosis non-invasively. Since chronic inflammation may accelerate atherosclerosis in end-stage renal disease patients, the aim of this 1 year study was to assess changes in CCA-IMT in stable peritoneal dialysis (PD) patients, and to search for possible associations between these changes and selected cytokines, acute phase proteins and other risk factors of atherosclerosis. METHODS: Of the original cohort of 61 stable patients on PD-28 female, 33 male; mean age 50.4+/-13.6 years; dialyse for a median of 17.5 months at inclusion (range 1-96 months)-47 patients survived the 1 year period on PD. CCA-IMT was assessed at baseline and after 12 months. Pro-inflammatory cytokines (IL-6, TNFalpha), acute phase proteins (CRP, fibrinogen), calcium-phosphate balance and lipid profile were assessed at baseline and after 6 and 12 months. Anthropometric parameters (age, weight, BMI, waist-to-hip ratio) were measured at baseline. RESULTS: The mean CCA-IMT at baseline, 0.66+/- 0.19 mm, increased by a mean of 0.098+/-0.17 to 0.76+/-0.21 mm (P<0.001) in 1 year. In 14 patients (29.8%) at least one plaque was found in the CCAs examined. At the end of follow-up: 28 patients (59.6%) had increases in CCA-IMT (from 0.63+/-0.2 to 0.83+/- 0.21 mm; P = 0.03), and 19 (40.4%) remained stable or even showed slight, but non-significant, decreases of CCA-IMT (from 0.72+/-0.17 to 0.66+/-0.17 mm, P = NS). The 'progressors' had significantly higher initial BMI (P<0.05), and mean concentrations of calcium (P = 0.005), IL-6 (P = 0.05), TNFalpha (P = 0.05), CRP (P = 0.005) and lower HDL-cholesterol than 'non-progressors'. In univariate analysis, DeltaCCA-IMT correlated positively with age (R = 0.32, P = 0.03), BMI (R = 0.29, P = 0.05) and mean concentrations of CRP (R = 0.37, P = 0.01), TNFalpha (0.52, P = 0.0002), but inversely with HDL-cholesterol (R = -0.37, P = 0.01). In multiple regression analysis, however, only age appeared to be independently associated with increase in CCA-IMT (beta = 0.37, P<0.01; R(2) for the model 0.14). CONCLUSIONS: Our results suggest a possible role of non-specific inflammation in the progression of atherosclerosis in patients treated with PD, in addition to age.     

The impact of malnutrition on mortality in patients on maintenance hemodialysis in Serbia

Numerous studies suggest a strong association between nutrition and clinical outcome in chronic hemodialysis (HD) patients. While determination of malnutrition is often based on objective measurements, such as biochemical parameters and anthropometric data, there is no single measurement that can reliably predict the risk for malnutrition or poor outcome. The aim of the present investigation was to determine the prevalence and severity of malnutrition among HD patients in a large university-affiliated HD center in Serbia, and to examine the relationship between various nutritional and nonnutritional factors, and the clinical outcome in the period of 20 months follow-up. The prospective observational cohort study included patients (n = 197) with more than 3 months on HD treatment before entering the study. Global nutritional status was evaluated by the dialysis malnutrition score (DMS). Body mass index (BMI), triceps skinfold thickness (TSF), mid-arm circumference (MAC), and mid-arm muscle circumference (MAMC), as well as several laboratory parameters and clinical examination, were recorded. Dose of HD and protein equivalence of nitrogen appearance normalized to ideal body weight (nPNA) were evaluated by the urea kinetic model. Mortality data were collected prospectively during the 20 months of follow-up. A moderate/severe degree of malnutrition was presented in 39.2% of female and 22.8% of male patients, while signs of mild malnutrition existed in 45.5% and 66.9% of patients, respectively. Kaplan-Meier survival analysis showed that in the entire group of patients with DMS score >10, the mortality rate was higher (log rank 5.61; P < 0.05) than in those with DMS score 相似文献   

Insulin resistance is associated with circulating fibrinogen levels in nondiabetic patients receiving peritoneal dialysis.

BACKGROUND: Insulin resistance (IR) and inflammation are associated with increased risk of cardiovascular disease in the general population. Continuous glucose absorption in peritoneal dialysis (PD) may induce hyperglycemia and hyperinsulinemia. METHODS: We evaluated IR in nondiabetic patients receiving PD, and analyzed the association between IR and systemic inflammation biomarkers by performing a cross-sectional study on ambulatory dialysis. A total of 25 nondiabetic patients receiving PD and 25 healthy individuals, matched for gender, age, and body mass index (BMI), were included. The PD group was composed of 11 men and 14 women, with a mean age of 47 +/- 14 years and mean BMI of 25.5 +/- 4.7 kg/m(2). The control group was composed of 10 men and 15 women, with a mean age of 45 +/- 12 years and BMI of 24.0 +/- 2.8 kg/m(2). RESULTS: IR was evaluated by the homeostasis model assessment method (HOMA-IR). Inflammation was assessed through high-sensitivity C-reactive protein (CRP) and fibrinogen. Body composition and truncal fat were evaluated by dual energy x-ray absorptiometry. HOMA-IR was significantly higher (P < .0001) in subjects receiving PD (4.9, range: 2.3-9.3 mmol/L x muU/mL) compared with healthy subjects (1.2, range: 0.4-4.8 mmol/L x muU/mL). As expected, compared with controls, patients receiving PD had significantly higher levels of insulin (26.5 +/- 7.5 muU/mL vs 6.3 +/- 3.4 muU/mL; P < .0001), CRP (6.3, range: 0.3-61.1 mg/L vs 2.4, range: 0.6-5.9 mg/L; P = .001), and fibrinogen (379 +/- 101 mg/dL vs 268 +/- 66 mg/dL; P < .0001). However, there were no significant differences in body and truncal fat mass between the groups. A significant correlation between HOMA-IR and fibrinogen (Rho = 0.48; P = .01) was observed. However, no correlation was found between HOMA-IR and CRP. Also, no significant correlations were found between HOMA-IR and body fat mass (Rho = 0.11), and between HOMA-IR and truncal fat mass (Rho = 0.19). CONCLUSIONS: Patients receiving PD demonstrate a state of IR that is associated with high circulating levels of fibrinogen. This suggests that hyperfibrinogenemia may be involved in the pathogenesis of IR in this setting.     

Intradialytic amino acids supplementation in hemodialysis patients with malnutrition: results of a multicenter cohort study.

OBJECTIVE: Prospective evaluation of the effect of 6-month-long intradialytic amino acids (AA) supplementation on selected nutritional variables in malnourished hemodialysis (HD) patients. DESIGN: Multicenter, prospective, (nonrandomized, noncontrolled) observational study. SETTING: Thirty-one HD units affiliated with academic centers and tertiary-care hospitals. PATIENTS: Adult patients treated by HD for at least 6 months. Inclusion criteria were: serum albumin concentration < or =39 g/L and at least 4% loss of body weight during the last 6 months in otherwise stable HD patients. From a cohort of 133 patients who were enrolled, 97 (54 men and 43 women) were eligible for the analysis. INTERVENTION: Intradialytic AA supplementation with 500 mL 10% solution per HD session for a period of 6 months. MAIN OUTCOME MEASURES: Serum albumin concentration, modified Subjective Global Assessment (SGA) score, body mass index (BMI), mid-arm circumference (MAC), and total lymphocyte count. Measurements were recorded at baseline and after 3 and 6 months of AA supplementation. RESULTS: Serum albumin concentration increased significantly from the mean 32.5 +/- 4.6g/L at baseline to 36.4 +/- 4.8 g/L at 3 months (P <.001) and 37.1 +/- 4.8 g/L at final observation (P <.001 versus baseline). Significant correlation was observed between frequency of AA supplementation and serum albumin increase (r = 0.41; P <.0001). Rate of improvement negatively correlated significantly with baseline concentration of serum albumin (r = - 0.42; P <.0001). SGA score significantly improved from median of 16 points at baseline to 12 points at 3 months (P <.01) and 11 points at 6 months (P <.01 versus baseline), and this improvement also correlated with the frequency of AA supplementation. Small yet significant increase of MAC was observed at 6 months (from baseline 24.1 +/- 4.3 to 24.8 +/- 4.8 cm; P <.01), whereas BMI remained unchanged. CONCLUSION: Intradialytic AA supplementation improves selected nutritional parameters of HD patients with malnutrition. The improvement depends on the intensity of supplementation.     

Cardiac troponin I and beta 2 microglobulin as risk factors for early-onset atherosclerosis in patients on haemodialysis

AIM: To investigate the associations of different risk factors with carotid artery intima-media thickness (C-IMT) in non-diabetic haemodialysis (HD) patients who had no clinical evidence of atherosclerosis. METHODS: Seventy-two HD patients (43 men, 29 women; mean age: 34.5 +/- 10.6 years; mean time on HD: 47.9 +/- 40.0 months) and 40 age- and sex-matched healthy controls (26 men, 14 women; mean age: 35.5 +/- 7.1 years) participated in the study. The relationship between C-IMT and haematocrit-corrected erythrocyte sedimentation rate (Hct-corrected ESR), beta 2 microglobulin (beta2M) and serum cardiac troponin I (cTnI) levels beyond C-reactive protein (CRP), lipid profile and lipoprotein(a), fibrinogen, homocysteine and left ventricular hypertrophy (LVH) were examined. RESULTS: Mean C-IMT of the HD patients was significantly greater than that of the control subjects (0.59 +/- 0.06 vs 0.53 +/- 0.07 mm, P = 0.002). C-IMT of patients was positively correlated with age (r = 0.33), body mass index (r = 0.40), Hct-corrected ESR (r = 0.37), CRP (r = 0.34), beta2M (r = 0.34), cTnI (r = 0.26), triglyceride (r = 0.26) and fibrinogen (r = 0.28) levels (P < 0.05 for all). The mean C-IMT was significantly greater in patients with LVH than it was in those without LVH (P = 0.004). In multivariate regression analysis, age (P = 0.02), beta2M (P = 0.001), log-transformed CRP (P = 0.03) and LVH (P = 0.01) were independently related with C-IMT. CONCLUSION: Besides well-known cardiovascular (CV) risk factors, cTnI and beta2M were related with C-IMT in that they may have important roles in early-onset atherosclerosis in this high-risk population.     

Association between extracellular water, left ventricular mass and hypertension in haemodialysis patients.

BACKGROUND: Hypertension and left ventricular hypertrophy (LVH) are present in the majority of patients undergoing haemodialysis (HD). These two pathologies persist after dialysis onset, and pharmacological therapy is often required for adequate control of blood pressure (BP). Although fluid overload is a determinant of hypertension, clinical assessment of this parameter remains difficult and unsatisfactory. Bioimpedance analysis (BIA) spectroscopy and the relative determination of extracellular water (ECW%) may provide a simple and inexpensive tool for investigating fluid overload. We studied 110 patients on thrice-weekly HD to determine whether ECW body content correlates with hypertension and LVH in this patient population. METHODS: Hypertension was determined according to the WHO criteria (office BP >/= 140/90 and/or the use of antihypertensive therapy). Twenty-four hour BP monitoring and echocardiography were performed on midweek inter-HD days. Blood chemistries, dialysis dose (spKt/V) and bioimpedance were analysed on midweek HD days. RESULTS: Hypertension was present in 74.5% of patients. There were no differences for age, spKt/V, haemoglobin, serum creatinine and residual renal function between normotensive and hypertensive patients. Twenty-four hour systolic BP (SBP), 24 h diastolic BP and 24 h pulse pressure were higher in hypertensive patients, in spite of antihypertensive therapy. LVH was present in 61.8% of patients. BIA revealed that ECW% was increased in LVH+ patients (LVH+ = 47.5 +/- 7.9%, LVH- = 42.4 +/- 6.2%, P = 0.01) and in hypertensive patients compared with normotensives (46.5 +/- 7.7% vs 43 +/- 7.2%, P = 0.02). Dry body weights and inter-HD body weight increases did not differ between hypertensive and normotensive patients nor between patients with or without LVH. ECW was correlated with SBP (r = 0.35, P < 0.01) and with left ventricular mass index (LVMi(g/sqm)) (r = 0.49, P < 0.001). A stepwise multiple linear regression model revealed that LVMi(g/sqm) was significantly correlated with ECW%, SBP and male gender (r = 0.65, P < 0.001). CONCLUSIONS: LVH and hypertension are present in a majority of HD patients and they are closely correlated with one another. We found associations between fluid load, measured by BIA and expressed as ECW, and BP and LVM.     

Ambulatory blood pressure monitoring in patients receiving long, slow home haemodialysis.

BACKGROUND: Good blood pressure (BP) control has been reported previously in haemodialysis (HD) patients receiving 8-h dialysis sessions. Home HD allows patients to dialyze for long periods, but there are few data on the BP control achieved by these patients. We studied BP control, using ambulatory blood pressure monitoring (ABPM), in our home-HD patients who were receiving long-hours dialysis. METHODS: Twenty-four patients aged 52.7+/-11 years underwent ABPM. They had been on home HD for 52.9+/-39 months and dialysed for 7.2+/-1.1 h thrice weekly. Two patients were taking antihypertensive drugs. Historical data on BP and weight gains were obtained from the patients' own records. Left ventricular (LV) mass was assessed by echocardiography and total body water (TBW) by bioelectrical impedance. RESULTS: The mean 24-h BP was 129+/-17 mmHg (systolic) and 83+/-14 mmHg (diastolic). The daytime BP was 131+/-17 mmHg (systolic) and 84+/-14 mmHg (diastolic), while the night-time BP was 126+/-22 mmHg (systolic) and 81+/-17 mmHg (diastolic). Six patients (25%) had a normal circadian BP rhythm, but the rest showed a subnormal fall or an increase in BP at night. Mean 24-h BP did not correlate significantly with time on dialysis, dialysis session length, Kt/V, haemoglobin, interdialytic weight gain, or TBW. Twenty-one patients (87%) had LV hypertrophy and 16 of these had diastolic dysfunction. LV mass index was inversely correlated with nocturnal BP fall (r=-0.54, P=0.03). Non-dippers had been treated longer than dippers (29 vs 59.2 months, P=0.03) but they were similar in respect to age, dialysis session length or Hb concentration. CONCLUSIONS: Long, slow haemodialysis at home provides satisfactory daytime BP control in the majority of patients without the need for antihypertensive drugs but abnormal circadian BP rhythm and LV hypertrophy remain common.     

Increases in serum leptin levels during peritoneal dialysis are associated with inflammation and a decrease in lean body mass

Leptin, secreted from fat cells, functions as a lipostat mechanism through modulation of satiety signals. Markedly elevated leptin levels have been documented in uremic patients, especially in those who are treated by peritoneal dialysis (PD). However, the role of hyperleptinemia in uremic patients is not clear, and it is not known whether elevated leptin levels contribute to uremic anorexia and changes in body composition. In this prospective study, serum leptin, C-reactive protein (CRP), plasma insulin, and body composition (dual-energy x-ray absorptiometry) were measured in 36 patients (53 +/- 1 yr) close to start and after about 1 yr of PD. In addition, markers of dialysis adequacy and urea kinetics were followed during treatment with PD. During PD, the total body fat mass (20.5 +/- 1.0 to 22.9 +/- 1.3 kg; P < 0.01), truncal fat mass (11.5 +/- 0.7 to 13. 2 +/- 0.9 kg; P < 0.001), and serum leptin levels (20.1 +/- 3.8 to 35.6 +/- 6.8 ng/ml; P < 0.01) increased markedly, especially in patients with diabetes mellitus. Twenty-five PD patients that lost lean body mass during PD had significantly (P < 0.05) elevated initial CRP levels (14 +/- 2 mg/L) compared to 11 patients (<10 mg/L) who gained lean body mass during PD. A significant increase in serum leptin levels (20.9 +/- 4.2 to 42.7 +/- 4.0 ng/ml; P < 0.001) was observed in those patients who lost lean body mass, whereas no such change (18.4 +/- 8.4 to 19.2 +/- 6.4 ng/ml) was observed in the patients that gained lean body mass during PD treatment. The present longitudinal results demonstrate that serum leptin level and body fat content increase markedly during PD, especially in diabetic patients. Patients that lost lean body mass during PD had higher initial CRP levels and increased their serum leptin levels significantly during PD compared to those patients that gained lean body mass. Additional studies are therefore needed to elucidate the role of hyperleptinemia and inflammation in causing anorexia, protein-malnutrition, and changes in body composition during treatment with PD.     

Changes in fat mass after initiation of maintenance dialysis is influenced by the uncoupling protein 2 exon 8 insertion/deletion polymorphism.

BACKGROUND: A high body mass index (BMI) has been reported to confer a survival advantage in end-stage renal disease (ESRD) patients. On the other hand, body fat accumulation, especially visceral adipose tissue, is an important risk factor for cardiovascular disease, as well as a clinically important source of adipokines. Uncoupling protein 2 (UCP2) uncouples respiration from ATP synthesis, thus regulating energy expenditure and fat oxidation. In this longitudinal cohort study, we investigated the impact of the UCP2 insertion/deletion (ins/del) polymorphism on body composition changes in ESRD patients starting dialysis. METHODS: A total of 222 incident Caucasian ESRD patients (mean age 53 +/- 12 years; 60% males) were investigated close to the start of dialysis with peritoneal dialysis (PD; n = 126) or haemodialysis (HD; n = 96), and again after about 1 year (n = 159). Genotyping of the UCP2 ins/del polymorphism was performed in the patients and in 207 healthy controls. Dual-energy X-ray absorptiometry was conducted at baseline and after 1 year to monitor body composition. RESULTS: While HD patients and PD patients with the ins/del genotype did not display any changes in body composition, the 48 PD patients with the del/del genotype that completed follow-up had a significant increase; DeltaBMI (0.7 +/- 1.8 kg/m(2)), Deltabody fat mass (3.5 +/- 3.8 kg) and Deltatruncal fat mass (1.7 +/- 1.2 kg). In a multiple linear regression analysis, the del/del genotype was an independent predictor of the increase in truncal fat mass in PD patients (F-ratio = 7.99, P < 0.05) together with age and diabetes mellitus. CONCLUSIONS: PD patients, but not HD patients, with the UCP2 del/del genotype showed a significant increase in total and truncal fat mass during the first year of dialysis therapy, suggesting a possible role for UCP2 in dissipating the excess energy of a high-glucose environment.     

A randomized controlled trial of haemoglobin normalization with epoetin alfa in pre-dialysis and dialysis patients.

BACKGROUND: Partial correction of renal anaemia with erythropoietin improves quality of life (QoL). We aimed to examine if normalization of haemoglobin with epoetin alfa in pre-dialysis and dialysis patients further improves QoL and is safe. METHODS: 416 Scandinavian patients with renal anaemia [pre-dialysis, haemodialysis (HD) and peritoneal dialysis patients] were randomized to reach a normal haemoglobin of 135-160 g/l (n=216) or a subnormal haemoglobin of 90-120 g/l (n=200) with or without epoetin alfa. Study duration was 48-76 weeks. QoL was measured using Kidney Disease Questionnaires in 253 Swedish dialysis patients. Safety was examined in all patients. RESULTS: QoL improved, measured as a decrease in physical symptoms (P=0.02), fatigue (P=0.05), depression (P=0.01) and frustration (P=0.05) in the Swedish dialysis patients when haemoglobin was normalized. In pre-dialysis patients, diastolic blood pressure was higher in the normal compared with the subnormal haemoglobin group after 48 weeks. However, the progression rate of chronic renal failure was comparable. In the normal haemoglobin group (N-Hb), 51% had at least one serious adverse event compared with 49% in the subnormal haemoglobin group (S-Hb) (P=0.32). The incidence of thrombovascular events and vascular access thrombosis in HD patients did not differ. The mortality rate was 13.4% in the N-Hb group and 13.5% in the S-Hb group (P=0.98). Mortality decreased with increasing mean haemoglobin in both groups. CONCLUSIONS: Normalization of haemoglobin improved QoL in the subgroup of dialysis patients, appears to be safe and can be considered in many patients with end-stage renal disease.