A cross-sectional study evaluating the prevalence and predictors of malnutrition among children and adolescents visiting an urban academic hospital in Nepal.

OBJECTIVE: To examine the prevalence of malnutrition among children and adolescents visiting Kanti Children's Hospital (KCH) and identify predictors associated with malnutrition. Results will guide the development of a newly established nutrition programme at KCH. DESIGN: This cross-sectional pilot study recruited children and adolescents over a 1-month period. Nutritional anthropometrics (height, weight and mid-upper arm circumference (MUAC)) and socio-demographic questionnaires were administered. Clinical data were abstracted from the medical chart. SETTING: KCH in Kathmandu, Nepal. PARTICIPANTS: 370 children and adolescents. RESULTS: Most participants were male (65·1 %); mean age was 3·9 years (±3·4 years). The prevalence of stunting was 25·9 %, wasting was 17·3 % and 24·0 % when classified by BMI-for-age Z-score or MUAC, respectively. Two percent of participants were overweight. Notably, 32·1 % of children ≥5 years were classified with wasting based on MUAC-for-age Z-score, which is higher than that observed in children <5 (20·2 %). Food insecurity was reported among 58·2 % of children with stunting and 34·0 % with wasting. Chronic medical conditions predicted stunting and wasting. The lowest level of wealth predicted stunting, while ethnicity predicted wasting. Ethnicity and education level predicted food insecurity. CONCLUSIONS: We found that the prevalence of stunting and wasting at KCH are higher than previously published studies in Nepal. Malnutrition persists beyond 5 years, and we identified several predictors of malnutrition. Increased provision of and access to clinical nutrition programmes is an essential need for KCH. Twinning programs that provide local clinicians with increased opportunities for education and mentorship of local staff remains a pressing need in Nepal.

Mortality and Low Serum Bicarbonate Level in Patients on Hemodiafiltration versus Peritoneal Dialysis.

Mortality is substantially elevated in patients on chronic kidney disease in comparison to general population. In this study, we observed the mortality rate in relation to risk factors including low serum bicarbonate level, coronary artery disease (CAD), and dialysis modality in patients on dialysis during a median follow-up time of 60 months. We studied 96 dialysis patients, 62 males and 34 females, on mean age 62.1 ± 14.27 years old. The treatment modalities which were applied were predilution hemodiafiltration (HDF, n = 76), and peritoneal dialysis (PD, n = 20). We performed Kaplan-Meier curves and a Cox-regression analysis to investigate significant risk factors for mortality including hypertension, diabetes mellitus, smoking, bone disease defined by intact-parathormone, serum albumin, serum bicarbonate levels < or >22 mEq/L, dialysis modality, and the existence of CAD. Cox-regression analysis revealed a significant impact of serum bicarbonate levels <22 mEq/L on mortality in combination to dialysis modality and CAD. The prevalence of CAD on mortality was found significant (log-rank = 5.507, P = 0.02). Furthermore, the impact of dialysis modality on mortality was shown significant (log rank = 22.4, P = 0.001), noting that during the first 28-30 months from the treatment initiation, the survival was better for PD; but then, the mortality was significantly increased comparatively to HDF. Uncorrected metabolic acidosis and CAD were shown as independent significant predictors for mortality in patients on renal replacement therapy. PD may provide worse survival after 2-2.5 years of treatment initiation than HDF.

The association between the spatial QRS-T angle with cardiac autonomic neuropathy in subjects with Type 2 diabetes mellitus.

AIMS: To examine differences in the spatial QRS-T angle in patients with Type 2 diabetes mellitus with and without cardiac autonomic neuropathy. METHODS: Two hundred and thirty-two patients with diabetes mellitus (105 with cardiac autonomic neuropathy and 127 without cardiac autonomic neuropathy) and 232 control subjects, matched by gender and age, were studied. Diagnosis of cardiac autonomic neuropathy was based on the classic autonomic function tests. All subjects underwent a digital electrocardiographic recording. Electrocardiographic parameters were measured using the Modular Electrocardiographic Analysis (MEANS) program. Left ventricular mass index (LVMi) and global myocardial performance index (Tei index) of the left ventricle were assessed by ultrasonography. RESULTS: The spatial QRS-T angle was higher in the patients with diabetes in comparison with the control subjects (24.5 ± 10.7 vs. 9.7 ± 4.5°, P < 0.001) and in the patients with diabetes and cardiac autonomic neuropathy than in those without cardiac autonomic neuropathy (30.1 ± 11.3 vs. 19.5 ± 7.1, P < 0.001). No differences were found in the QT interval between the studied groups. Multivariate linear regression analysis in subjects with diabetes after controlling for age, gender, BMI, blood pressure, diabetes duration, HbA(1c) , lipids, microalbuminuria and insulin resistance, demonstrated significant and independent associations between the spatial QRS-T angle with presence and severity of cardiac autonomic neuropathy, all parameters of heart rate variability, LVMi and Tei index. CONCLUSIONS: The spatial QRS-T angle is increased in patients with Type 2 diabetes who have cardiac autonomic neuropathy, suggesting increased ventricular arrhythmogenicity, and is associated with the structural and functional properties of the myocardium. Further research is warranted to evaluate its role in cardiovascular risk stratification of patients with diabetes.

Increased plasma ghrelin levels in chronic renal failure are not associated with hemodynamic parameters.

BACKGROUND/AIMS: Hardly anything is known about the effect of renal function on plasma ghrelin levels. Ghrelin is an orexigenic hormone with important hemodynamic effects. We examined differences in plasma ghrelin levels between chronic renal failure (CRF) patients and healthy subjects, and ghrelin's relationship with indices of left ventricular (LV) function. METHODS: Fasting total plasma ghrelin levels were measured in 122 CRF patients (57 on, 65 not on hemodialysis) and 57 control subjects. Indices of LV function were evaluated using echocardiography. RESULTS: Total plasma ghrelin levels were higher in patients with CRF compared to controls, but were not different between patients on and those not on hemodialysis. In a multivariate linear regression model, presence of kidney dysfunction explained 41 % of the variability of ghrelin values. The etiology of renal failure (diabetic nephropathy or not) had no influence on ghrelin levels in the renal patients. Ghrelin levels were not associated with indices of LV systolic function or blood pressure in these patients. CONCLUSION: Fasting plasma ghrelin concentrations are higher in CRF patients regardless of their need for hemodialysis compared to controls. The etiology of renal failure does not have any effect on plasma ghrelin levels. In addition, ghrelin levels are not associated with hemodynamic parameters in patients with CRF.

Acute nateglinide administration in subjects with type 2 diabetes: effects on postprandial metabolism, coagulation, and fibrinolysis.

BACKGROUND AND AIM: Postprandial glycaemia and lipaemia are known risk factors for atherosclerosis in type 2 diabetes. Coagulation activation in the postprandial state also contributes to acceleration of atherosclerosis. Nateglinide is effective in reducing postprandial glycaemia. Its effect on glycaemia may also be beneficial in postprandial lipaemia and coagulation. The aim of this study was to examine the potential effect of a single dose of nateglinide on postprandial triglyceridaemia, coagulation, and fibrinolysis in patients with type 2 diabetes. METHODS AND RESULTS: Ten subjects with type 2 diabetes, treated with diet alone were recruited in a crossover randomized study. In the morning, after a 12- to 14-h fast, each subject received a standard mixed meal (total energy 783 kcal), preceded by one tablet of 120 mg nateglinide or placebo. Venous blood samples were drawn prior to meal consumption and 6h afterwards for the measurement of plasma glucose, insulin, and C-peptide, lipids, coagulation, and fibrinolysis factors. As expected, there was a significant reduction in postprandial glycaemia after nateglinide administration compared to placebo (P<0.001). Plasma insulin levels were significantly higher after nateglinide than after placebo (P=0.002). Nateglinide administration resulted in a lower overall postprandial reduction of tissue-plasminogen activator than placebo (-2.9+/-1.3 vs. -8.3+/-3.7 ng/ml h, P=0.003). In addition, a significant reduction of postprandial plasminogen activator inhibitor-1 was observed in comparison with the baseline values after nateglinide (P=0.001), although the overall response was not significantly different after nateglinide and placebo (P=0.31). Plasma concentrations of C-peptide, lipids and the remaining coagulation parameters studied were not different between nateglinide and placebo. CONCLUSIONS: Acute nateglinide administration improves postprandial glycaemia and fibrinolytic activity in patients with type 2 diabetes. This combined effect, if confirmed by a long-treatment study, might reduce cardiovascular risk in type 2 diabetes.

Plasma adiponectin concentrations in patients with chronic renal failure: relationship with metabolic risk factors and ischemic heart disease.

AIMS: To compare plasma adiponectin levels between healthy controls and patients with chronic renal failure and to examine for a relationship between plasma adiponectin levels and ischemic heart disease as well as aortic distensibility which is an early marker of atherosclerosis. METHODS: We included 89 patients with CRF (45 on and 44 not on hemodialysis) and 70 controls in a cross-sectional study. Plasma adiponectin levels were measured by radioimmunoassay. Aortic distensibility was assessed by high-resolution ultrasonography. RESULTS: Plasma adiponectin levels were significantly almost twice as high in patients with renal failure compared to controls (9.7 +/- 1.1 vs. 5.4 +/- 0.6 microg/ml, p < 0.0001). No significant differences were found between renal patients on hemodialysis and not on hemodialysis (p = 0.71). Multivariate linear regression analysis in the renal patient group demonstrated a significant negative relationship between plasma adiponectin levels and ischemic heart disease (p = 0.02). The same analysis in the control subjects group showed a significant, negative relationship between plasma adiponectin levels and body mass index (p = 0.02) and a highly significant positive relationship with the high density lipoprotein cholesterol (p < 0.0001). In the total study population, glomerular filtration rate was the only independent predictor of plasma adiponectin concentrations. Aortic distensibility was lower in renal patients than in controls at a high level of significance (p < 0.0001). However, no significant relationship could be found between plasma adiponectin and aortic distensibility in either the controls or the renal patients. CONCLUSIONS: Plasma adiponectin levels are almost twice as high in patients with chronic renal failure in comparison with healthy controls, but not different between renal patients on and those not on hemodialysis. In addition, low plasma adiponectin levels are strongly associated with ischemic heart disease, but not with aortic distensibility in chronic renal failure.

Differential effects of high-fat and high-carbohydrate content isoenergetic meals on plasma active ghrelin concentrations in lean and obese women.

AIM: To study the effect of two different isoenergetic meals, one rich in carbohydrates and one rich in fat, on plasma active ghrelin levels in lean or obese subjects. METHODS: Eight obese and eight lean women, strictly matched for age, were fed two isoenergetic meals of different composition, one rich in fat and one rich in carbohydrates (CHO), on separate days. Plasma active ghrelin levels were measured just before and at 1, 2 and 3 hours after meal consumption. RESULTS: Overall, plasma active ghrelin levels were significantly lower in the obese compared to the lean women (71.7 +/- 29.7 vs. 222.2 +/- 127.2 pmol/liter respectively, p < 0.0001). Furthermore, ghrelin levels decreased significantly by 30 % from baseline values in the lean subjects in the first hour after the CHO-rich meal (mean difference +/- SD): -66.2 +/- 49.0 pmol/liter (p = 0.03), returning to near-baseline levels by 2 hours, while no significant change was observed in the obese subjects. After the fat-rich meal, active ghrelin levels did not change significantly in either group (p > 0.05). CONCLUSIONS: A fat-rich meal does not suppress plasma active ghrelin levels in either lean or obese women. Moreover, in obese, unlike lean women, a high carbohydrate meal also fails to suppress plasma ghrelin levels, which are already quite low. This suggests that ghrelin-induced satiety mechanisms may be compromised in these subjects.

Differential effects of high-fat and high-carbohydrate isoenergetic meals on cardiac autonomic nervous system activity in lean and obese women.

Food ingestion can influence autonomic nervous system activity. This study compares the effects of 2 different isoenergetic meals on sympathetic nervous system (SNS) activity, assessed by heart rate variability (HRV) and plasma norepinephrine (NE) levels, in lean and obese women. Fifteen lean and 15 obese healthy women were examined on 2 occasions: after a carbohydrate (CHO)-rich and after a fat-rich test meal. Measurements of blood pressure, heart rate, resting energy expenditure, plasma glucose, lipids, insulin, leptin, and NE, as well as spectral analysis of the HRV, were performed at baseline and every 1 hour for 3 hours after meals. At baseline, obese women had higher SNS activity than lean controls (higher values of low-to-high frequency ratio [LF/HF], 1.52 +/- 0.31 v 0.78 +/- 0.13, P=.04; and plasma NE levels, 405.6 +/- 197.9 v 240.5 +/- 95.8 pg/mL, P<.0001). After the CHO-rich meal a greater increase in LF/HF and in plasma NE levels was observed in lean, compared to obese women (1.21 +/- 0.6 v 0.32 +/- 0.06, P=.04; and 102.9 +/- 35.4 v 38.7 +/- 12.3 pg/mL, P=.01, respectively), while no differences were observed after the fat-rich meal. Meal-induced thermogenesis was higher after the CHO-rich as compared to the fat-rich meal and was comparable between lean and obese women. Changes in HRV were not associated with the thermogenic response to the test meals. In conclusion, consumption of a CHO-rich meal causes greater cardiac SNS activation in lean than in obese women, while fat ingestion does not result in any appreciable change in either group. SNS activation does not appear to influence the thermic effect of the food in either lean or obese women.

Lack of effect of acute repaglinide administration on postprandial lipaemia in patients with type 2 diabetes mellitus.

The effect of acute repaglinide administration (2 mg) on postprandial glycaemia and lipaemia has been examined in 20 subjects with type 2 diabetes mellitus. Each subject received in the morning, after a 12 to 14 h fast, a standard mixed meal (total energy 783 kcal), preceded by one tablet of 2 mg repaglinide or placebo. Chylomicrons and chylomicron-deficient plasma were prepared by ultracentrifugation. Triglyceride levels in CM fraction (CM-triglycerides) in total plasma as well as in CM-deficient plasma (non-CM-triglycerides) were determined. A significant reduction in postprandial glycaemia was observed after repaglinide administration compared to placebo ( p < 0.001). Plasma concentrations of total triglycerides, CM-triglycerides, non-CM-triglycerides, free fatty acids and the other plasma lipids measured, were not significantly different between the two phases of the study. It is concluded that, in contrast to sulphonylureas, acute repaglinide administration does not improve postprandial lipaemia in patients with type 2 diabetes.

Paucity of Sjogren-like syndrome in a cohort of HIV-1-positive patients in the HAART era. Part II.

OBJECTIVE: This study was performed in order to investigate the prevalence of Sjögren-like syndrome (SLS) in the highly active anti-retroviral therapy (HAART) era in a cohort of HIV-1-positive Greek patients. METHODS: One hundred and thirty-one unselected patients were screened by the validated European Union (EU) criteria for Sjögren's syndrome. Of the 31 who gave a positive EU-validated questionnaire, 17 consented to undergo minor salivary gland biopsy and other tests. RESULTS: Only two patients had a positive salivary gland biopsy and both belonged to the non-compliant HAART group, whereas none of the compliant HAART patients had histological findings. CONCLUSIONS: It is concluded that SLS, the prevalence of which in the pre-HAART era was 7.8%, has disappeared, possibly as a result of the protective action of HAART.

Pre-operative Tc-99m-sestamibi scanning and intra-operative nuclear mapping: are they accurate in localizing parathyroid adenomas?

PURPOSE: Presentation of the results of Tc-99m-sestamibi imaging in the pre-operative localization of parathyroid adenomas and the intra-operative localization of those lesions using a gamma detector (prospective study). PATIENTS & METHODS: Eighteen consecutive patients aged 27-75 years with primary hyperparathyroidism (PHPT) underwent Tc-99m-sestamibi scanning 1-2 hours before the operation and the presence of a single adenoma was recognized. All our patients underwent bilateral neck exploration based on pre-operative scanning and intra-operative gamma detector guidance and the adenoma was detected in the positions shown by both methods. RESULTS: In 16 patients we found a single adenoma localized in the same position shown by pre-operative scanning, while the intra-operative method accurately revealed all abnormal glands. In one of the two patients where an inaccurate pre-operative localization technique had been carried out, we performed thyroid lobectomy (the adenoma proved to be intrathyroidal), while the other one had an adenoma which was not close to the site indicated by the pre-operative scintigraphy. Serum calcium reverted to normal within a few days postoperatively. CONCLUSION: Patients with true-positive scans for single parathyroid adenoma could be eligible for minimally invasive operations since the abnormal gland is easily identified by the above-mentioned methods.

Anaemia in systemic lupus erythematosus: aetiological profile and the role of erythropoietin.

OBJECTIVE: To study the prevalence of different causes of anaemia in patients with systemic lupus erythematosus (SLE) and their associations with immunological and clinical parameters and to evaluate the contribution of erythropoietin (Epo) and anti-erythropoietin (anti-Epo) autoantibodies to the development of SLE anaemia. METHODS: 132 SLE patients with anaemia (defined as haemoglobin of 12 g/dl or less for women and 13.5 g/dl or less for men) from among a total of 345 consecutive SLE patients were prospectively enrolled into the study. Standard haematological and immunological tests were performed and serum Epo and anti-Epo antibodies were assayed. RESULTS: The identified causes were anaemia of chronic disease (ACD) n=49 (37.1%), iron deficiency anaemia (IDA) n = 47 (35.6%), autoimmune haemolytic anaemia (AHA) n = 19 (14.4%) and other causes n = 17 (12.9%). There was significant heterogeneity in the severity of anaemia between the four groups (p<0.01) with AHA cases being on average more severe. The proportion of patients with anticardiolipin antibodies, low complement levels and anti-dsDNA differed significantly among the four groups; these markers were particularly common in patients with AHA, and uncommon in patients with IDA. Twenty one of 100 tested patients had anti-Epo antibodies. Such antibodies were seen practically only in patients with ACD (odds ratio 3.1, p = 0.041) and in patients with high lupus activity (ECLAM) scores (odds ratio 1.27 per point, p = 0.055). Epo response was inadequate in 42.4% and 41.2% of patients with ACD and AHA, respectively. CONCLUSIONS: Anaemia in SLE usually takes the form of ACD and IDA, however autoimmune haemolysis is not uncommon. SLE patients with different causes of anaemia differ in regard to several immunological parameters. Epo response is blunted in anaemic SLE patients, particularly those with ACD and AHA.

Circulating autoantibodies to erythropoietin are associated with human immunodeficiency virus type 1-related anemia.

In a cohort of 204 unselected consecutive human immunodeficiency virus type 1 (HIV-1)-infected patients, the association of circulating autoantibodies to endogenous erythropoietin (EPO) with HIV-1-related anemia was studied. Circulating autoantibodies to EPO were present in 48 (23.5%) of the 204 patients studied. Circulating autoantibodies were an independent predictor of anemia (odds ratio [OR]=5.0; 95% confidence interval [CI], 2.5-9.9), as strong as other known causes of anemia. The association of anti-EPO antibodies with anemia became stronger when the analysis was limited to the group of patients without any medical condition causing anemia (OR=10.4; 95% CI, 3.2-33.9). Moreover, the effect on hemoglobin levels remained significant even after adjusting for other anemia parameters. Anti-EPO autoantibodies were associated with higher EPO levels (r=.25, P=.012) and with a more prominent EPO response to anemia. Our findings suggest that autoimmunity, among other factors, may contribute to the pathogenesis of HIV-1-related anemia.

Elevated plasma immunoreactive leptin levels preexist in healthy offspring of patients with essential hypertension.

BACKGROUND: Plasma leptin levels and plasma insulin levels have been found to be elevated in patients with essential hypertension (EH) and have been suggested to be components of the metabolic syndrome. Increased heart rate (HR) may predict the development of EH in normal or borderline-hypertensive individuals. The aim of our study was to test the hypothesis that elevated plasma leptin and insulin levels as well as systolic blood pressure (SBP) and diastolic blood pressure (DBP) and increased resting HR preexist in the healthy offspring of patients with EH. METHODS AND RESULTS: Twenty-six (12 male, 14 female) healthy offspring of hypertensive patients, mean age 16 +/- 2.5 years and body mass index (BMI) of 21.5 +/- 2.8 kg/m(2) (group A), and 30 (14 male, 16 female) healthy offspring of normotensive patients, mean age 17 +/- 2.3 years and BMI of 21.9 +/- 2.4 kg/m(2) (group B), were studied. (The two groups were matched for sex, age, and BMI). Mean SBP, DBP, resting HR, plasma leptin, and plasma insulin levels (radioimmunoassay method) were determined in the whole study population. Mean SBP, DBP, and resting HR were significantly higher in group A than in group B (120 +/- 12 vs 112 +/- 9.5 mm Hg, 77 +/- 9 vs 72 +/- 7 mm Hg, 79 +/- 8 vs 75 +/- 5 beats/min, P <.01, P <.05, and P <.05, respectively). Plasma leptin and insulin levels were significantly higher in group A than in group B (9 +/- 5.06 vs 5.6 +/- 2.5 ng/mL and 20.11 +/- 11.3 vs 14.8 +/- 5.2 microIU/mL, P <.01 and P <.05, respectively). CONCLUSIONS: Our findings support the hypothesis that hyperleptinemia, hyperinsulinemia, and elevated blood pressure and resting HR preexist in the healthy offspring of patients with EH.

Moxonidine effect on microalbuminuria, thrombomodulin, and plasminogen activator inhibitor-1 levels in patients with essential hypertension.

Increased sympathetic activity seems to play an important role in the pathogenesis and development of complications of atherosclerotic origin in patients with essential hypertension (EH). The aim of this study was to evaluate the effect of a new antihypertensive agent, moxonidine (M), on microalbuminuria (urine albumin excretion, UAE), plasma thrombomodulin (TM), and tissue plasminogen activator inhibitor (PAI-1) in patients with mild to moderate EH associated with increased UAE. Fifty-eight patients (32 M, 26 F) with EH and microalbuminuria, with a mean age of 56.6 +/- 8.2 years and a body mass index (BMI) of 23.8 +/- 3.1 kg/m2 who responded to M therapy (0.3-0.4 mg/daily) were studied before and after their blood pressure control. The 24-hour urine albumin excretion (RIA method), as well as TM and PAI-1 plasma levels (ELISA method), were determined before and 6 months after the initiation of treatment under moxonidine therapy. At the end of the 6-month period, all patients remained normotensive. The 24-hour urine albumin excretion had decreased to 24.5 +/- 6.4 vs. 32.3 +/- 7.2 ug/min before therapy (P < 0.001). The plasma TM levels had decreased to 44.0 +/- 7 vs. 51.0 +/- 9 ng/mL before therapy (P < 0.01), and PAI-1 levels had also decreased to 11.5 +/- 4.5 vs. 15.8 +/- 8 IU/mL before therapy (P < 0.05). The results of our study suggest that in hypertensive patients with microalbuminuria, moxonidine, an imidazoline I1-receptor agonist, a new centrally acting antihypertensive agent, significantly reduces urine albumin excretion as well as thrombomodulin and PAI-1 levels. These preliminary findings demonstrate a favorable effect on renal function and endothelial homeostatic mechanisms (maintenance of haemostatic balance).

Preliminary observations in the fasting serum gastrin in patients with duodenal ulcer; further evidence of the "clearing" effect of omeprazole on H pylori?

Thirty patients with active duodenal ulcer who were Helicobacter pylori positive (HP+) by HLO test and by histology (Giemsa stain) were given omeprazole (OME) 20 mg/d for a two-week period. Estimation of fasting serum gastrin concentration (RIA) was performed before treatment and 24 hours after the last dosage of OME, and HP was searched for an antral biopsies at the end of the treatment as well. Mean fasting serum gastrin concentration increased significantly after treatment in all patients studied (p less than 0.05). However, the increase remained significant only in those patients who continued to be HP+ while no significant increase was observed in those who became HP-. The results could be considered as further evidence of the 'clearing' effect of Omeprazole on HP.

Pituitary adrenal responsiveness to corticotropin-releasing hormone in chronic uremic patients.

We investigated the effect of exogenous ovine corticotropin-releasing hormone (oCRH) on plasma levels of adrenocorticotropic hormone (ACTH) and cortisol in 24 chronic renal failure patients: 8 nondialysis (NDCRF), 8 on hemodialysis (HD), and 8 on continuous ambulatory peritoneal dialysis (CAPD). In all groups the acute administration of oCRH caused a further increase (less pronounced in NDCRF patients) in the already elevated levels of cortisol. Following oCRH administration, plasma ACTH rose significantly in CAPD patients, but there was a blunted response of the hormone in the NDCRF and HD groups. The patterns of the ACTH and cortisol response in the last two groups, resemble those observed in chronic stress. We conclude that the hypothalamic-pituitary-adrenal axis in chronic uremic patients, retains the ability to respond to exogenous oCRH. Patients on CAPD, however, display a better, identical to normal response, which can be due to less chronic stress and/or to the more effective clearance of uremic toxins.