Evaluation of clinical named entity recognition methods for Serbian electronic health records.

BACKGROUND AND OBJECTIVES: The importance of clinical natural language processing (NLP) has increased with the adoption of electronic health records (EHRs). One of the critical tasks in clinical NLP is named entity recognition (NER). Clinical NER in the Serbian language is a severely under-researched area. The few approaches that have been proposed so far are based on rules or machine-learning models with hand-crafted features, while current state-of-the-art models have not been explored. The objective of this paper is to assess the performance of state-of-the-art NER methods on clinical narratives in the Serbian language. MATERIALS AND METHODS: We designed an experimental setup for a comprehensive evaluation of state-of-the-art NER models. The gold standard corpus we used for the evaluation is comprised of discharge summaries from the Clinic for Nephrology at the University Clinical Center of Serbia. The following models were evaluated: conditional random fields (CRF), multilingual transformers (BERT Multilingual and XLM RoBERTa), and long short-term memory (LSTM) recurrent neural networks, and their ensembles. In addition, we investigated the necessity of the pretraining task of transformer based models and the use of pretrained word embeddings with LSTM model. RESULTS: Our results show that individually CRF had the best precision, the pretrained BERT Multilingual model had the best recall values, and the LSTM model had the best F1 score. The best performance was achieved by combining the existing models in a majority voting ensemble with an F1 score of 0.892. The presented results are similar to the inter annotator agreement on our gold standard corpus and are comparable to existing state-of-the-art results for clinical NER reported in literature. CONCLUSION: Existing state-of-the-art models can provide viable results for clinical named entity recognition when applied to languages with the complexity of the Serbian language without major modifications.

Dual Roles of the Mineral Metabolism Disorders Biomarkers in Prevalent Hemodilysis Patients: In Renal Bone Disease and in Vascular Calcification.

BACKGROUND: Vascular calcification (VC) is highly prevalent in dialysis (HD) patients, and its mechanism is multifactorial. Most likely that systemic or local inhibitory factor is overwhelmed by promoters of VC in these patients. VC increased arterial stiffness, and left ventricular hypertrophy. Thus, the present study aimed to investigate the association of VC and myocardial remodeling and to analyze their relationship with VC promoters (fibroblast growth factor 23-FGF23, Klotho, intact parathormon-iPTH, vitamin D) in 56 prevalent HD patients (median values: age 54 yrs, HD vintage 82 months). METHODS: Besides routine laboratory analyzes, serum levels of FGF 23, soluble Klotho, iPTH, 1,25-dihydroxyvitamin D3; pulse wave velocity (PWV); left ventricular (LV) mass by ultrasound; and VCs score by Adragao method were measured. RESULTS: VC was found in 60% and LV concentric or eccentric hypertrophy in 50% patients. Dialysis vintage (OR 1.025, 95%CI 1.007-1.044, p=0.006) FGF23 (OR 1.006, 95% CI 0.992-1.012, p=0.029) and serum magnesium (OR 0.000, 95%CI 0.000-0.214, p=0.04) were associated with VC. Changes in myocardial geometry was associated with male sex (beta=-0.273, 95% CI -23.967 1.513, p=0.027), iPTH (beta 0.029, 95%CI -0.059-0.001, p=0.027) and vitamin D treatment (beta 25.49, 95%CI 11.325-39.667, p=0.001). Also, patients with the more widespread VC had the highest LV remodeling categories. PWV was associated patient's age, cholesterol, diastolic blood pressure, LV mass (positively) and serum calcium (negatively), indicating potential link with atherosclerotic risk. CONCLUSIONS: Despite to different risk factors for VC and myocardial remodeling, obtained results could indicate that risk factors intertwine in long-term treatment of HD patients and therefore careful and continuous correction of mineral metabolism disorders is undoubtedly of the utmost importance.

Predictive value of echocardiography and its relation to Kt/V and anthropometric parameters in hemodialysis patients.

BACKGROUND: In order to evaluate the predictive value of echocardiograph parameters for mortality of hemodialysis patients and their relation to Kt/V and anthropometry, a prospective, single center study was analyzed post-hoc. METHODS: This analysis encompassed 106 patients on maintenance hemodialysis monitored for 108 months from 1996 to 2004. spKt/V was calculated using the Daugirdas formula. Anthropometric measurements included mid-arm muscle measurements (MAMC) and percentage of body fat (%fat). Echocardiography included the estimations of left ventricular wall thickness, dimensions and volumes (EDV, ESV), systolic LV function (ejection fraction - EFLV, fractional shortening - VCF, stroke volume - SV) and diastolic LV function (E/A, VTI-A wave of transmitral flow velocity), left atrial diameter, as well as assessment of clinical and biochemical parameters. The Cox proportional hazard model was used to estimate predictive values of echocardiograph parameters. RESULTS: Kt/V correlated significantly with left ventricular systolic and diastolic volumes and function, septal and posterior wall thickness and left atrium dimension. MAMC and %fat also correlated with many echocardiograph parameters. Multivariate Cox regression selected age [HR 1.07; CI (1.03-1.12); p < 0.01], albumin [HR 0.88; CI (0.79-0.97); p < 0.05] and left atrium dimension - binary [values > 4 cm were marked as "1" and others "0" - HR 3.76; CI (1.56-9.03); p < 0.01] as independent predictors of death. CONCLUSION: Left atrium dimension was the most important predictor of mortality among the echocardiograph parameters. Many of these parameters were related to Kt/V and anthropometric measurements and could be the combined consequence of hypervolemia and hypertension.

Inflammatory markers as mortality predictors in continuous ambulatory peritoneal dialysis patients.

BACKGROUND/AIM: Besides peritonitis, the most common complication, indicators of chronic inflammation are also present in patients treated by peritoneal dialysis. The aim of this study was to analyze the predictive value of inflammatory parameters on mortality of continuous ambulatory peritoneal dialysis (CAPD) patients. METHODS: Eighty-seven patients (57 males), aged from 30 to 85 [62.92 (10.61)] years who had been treated by a chronic program of CAPD for 3-113 months were analyzed. The basal period lasted 3 months with a follow-up of 30 months. Clinical parameters, dialysis adequacy and laboratory parameters including some inflammatory markers: serum amyloid-A (SAA), high sensitive C-reactive protein (hs-CRP), fibrinogen, erythrocyte sedimentation rate (ESR) and leukocytes were determined for each patient. Cox regression analysis selected the parameters of univariate and multivariate survival analysis. RESULTS: During the follow-up period, 37 patients (42.5%) died. Univariate analysis selected the following potential mortality predictors (p<0.10): age, months on CAPD, residual urine output, presence of cerebrovascular insult (CVI), KT/V, serum urea and albumin concentrations, SAA, hs-CRP, fibrinogen and ESR. In the multivariate survival analysis four models were created, each with a single inflammatory parameter. In all of these models, besides the age and CVI, inflammatory parameters were the most significant mortality predictors. When the inflammatory markers were analyzed altogether, multivariate analysis established that independent mortality predictors in this group of patients were: SAA, age and CVI. CONCLUSION: It may be concluded that in this studied group treated by CAPD, SAA was the most significant independent mortality predictor among the analyzed inflammatory markers.

Association of small, dense low-density lipoprotein cholesterol and galectin-3 in patients with chronic kidney disease.

BACKGROUND: Dyslipidemia is a common feature of chronic kidney disease (CKD). Although it has been observed that the pattern of lipid abnormalities can vary according to the stage of CKD, there is lack of data concerning the distribution of lipoprotein subclasses at various stages of the disease. In addition, association of proatherogenic small, dense low-density lipoprotein (sdLDL) subclasses with markers of inflammation, such is galectin-3, is not sufficiently explored. The aim of this study was to analyze concentrations and relative proportions of sdLDL-cholesterol (sdLDL-C) and galectin-3 in patients with CKD, with respect to the stage of the disease. Also, we sought possible independent associations of galectin-3 and sdLDL-C. METHODS: The study involved 100 hemodialysis (HD) and 50 pre-dialysis patients, together with 94 healthy individuals. SdLDL-C was measured by heparin-magnesium precipitation method. Galectin-3 was measured by ELISA technique. RESULTS: Galectin-3 levels were higher in pre-dialysis and HD patients than in the control group (p < 0.01). The concentration of sdLDL-C was highest in the pre-dialysis group and lowest in HD patients (p < 0.01). CKD patients with increased galectin-3 concentrations had significantly higher relative proportions of cholesterol in sdLDL (% sdLDL-C) than their counterparts with lower galectin-3 levels (p < 0.05). Relative proportion of sdLDL-C was shown to be an independent determinant of galectin-3 concentration. CONCLUSIONS: Our results demonstrated alterations in concentrations and proportions of sdLDL-C according to the stages of CKD. The observed independent associations of % sdLDL-C and galectin-3 provide further insight into their complex interaction during the progression of atherosclerosis in CKD.

A comparison of markers of myocardial injury and their relation to nutritional parameters in hemodialysis patients.

BACKGROUND: Serum cardiac troponin T (cTnT) is a valuable marker of ischemic heart disease (IHD) and left ventricular hypertrophy, as well as a mortality predictor in hemodialysis populations. We compared the value of cTnT, creatinine kinase (CK)-MB mass and myoglobin as mortality predictors in our hemodialysis patients and evaluated their relation to nutritional status. METHODS: A total of 118 hemodialysis patients were prospectively studied from January 2004 to April 2013. Clinical and laboratory evaluations during the 12-month baseline period included the history of IHD, signs of left ventricular hypertrophy (LVH), Kt/V and serum cardiac markers together with the percentage of body fat (%fat), mid-arm circumference (MAC), mid-arm muscle circumference (MAMC), triceps skinfold (TSF) and BMI. RESULTS: Underweight patients had significantly higher cTnT values (Mann-Whitney, p<0.05). Correlation analysis (Spearman) showed an inverse association between cTnT and TSF (ρ=-0.22, p<0.05), as well as between CK-MB mass and TSF (ρ=-0.26, p<0.01). In men cTnT also correlated inversely with %fat (ρ=-0.27, p<0.05) and BMI (ρ=-0.33, p<0.05). In addition, myoglobin was correlated significantly with MAC, MAMC and albumin. Among cardiac markers cTnT was the only independent variable predicting mortality (Multivariate Cox regression, HR=1.04 CI (1.01-1.07); p<0.01; measurement units 0.01 µg/L). CONCLUSION: Troponin T and CK-MB mass were significantly elevated in the underweight patient group. Troponin T was the only independent cardiac marker predictor of all cause mortality in our hemodialysis patients.

[Different response to human recombinant erythropoietin in patients undergoing hemodialysis treatment].

INTRODUCTION: Treatment with recombinant human erythropoietin enabled the correction of anemia in the patients on regular hemodialysis but large individual differences in the dose required to achieve the target hemoglobin level were observed. In this study the erythropoietin resistance index was calculated in patients on hemodialysis in order to examine variations in the response to erythropoietin and factors that influence it. MATERIAL AND METHODS: The study included 48 patients (25 males) of mean age 67.5 years, who had been on regular hemodialysis in Samac for 43.9 months on average. All were treated with erythropoietin from the beginning of hemodialysis treatment. Their response to erythropoietin therapy was estimated by the erythropoietin resistance index. RESULTS: The use of erythropoietin enabled the correction of anemia but different doses were needed to achieve and maintain the target hemoglobin level. The individual weekly dose of erythropoietin ranged from 15 U/kg/week to 244 U/kg/week and the erythropoietin resistance index ranged from 0.13 U/kg/week/g/l to 2.46 U/kg/week/g/l. A satisfactory erythropoietin response with erythropoietin resistance index below 0.5 U/kg/week/g/l was found in 14 (30%) patients, while 19 (40%) patients had this index above 0.7 U/kg/week/g/l and 10 (21%) above 0.9 U/kg/week/g/l. Multivariate linear regression analysis detected C-reactive protein as a significant predictor of erythropoietin resistance index. CONCLUSION: Target hemoglobin levels were achieved and maintained by different doses of erythropoietin in individual patients, which resulted in great individual differences in response as estimated by the erythropoietin resistance index. Multivariate analysis indicated C-reactive protein as a variable significantly associated with this index.

Comparison of two diverse measurement methods by graphical agreement.

Biological processes are complex, and several methods are often used to measure them. However, different methods could determine diverse parts of a single biological process. To date, there are no widely accepted and convenient methods for comparison between the results, so we consider graphical analysis with the ability to demonstrate the pattern of distribution of findings from one method across another. It appears that a two-series area plot is the most appropriate. After using normal values and a coding reference and examining the variables, unnecessary information is diminished and the graphics become more obvious. Three possibilities may be found: agreement or disagreement between variables or disagreement from normal values. Therefore, the graph may also be used to determine the corresponding normal values between variables. The association between variables may be tested using kappa coefficients, although graphical analysis remains more informative. Therefore, graphical analysis could compare two completely different variables that measure the same biological process or determine the range of normal values.

Risk factors associated with coronary artery calcification should be examined before kidney transplantation.

The best treatment for end stage renal disease (ESRD) patients is kidney transplantation, but the renal transplant recipients still have a higher incidence of cardiovascular events compared with general population. Cardiovascular risk factors were imposed long before ESRD, as the majority of patients starting dialysis or kidney transplantation already have signs of advanced atherosclerosis. Artery calcification is an organized, regulated process similar to bone formation. Coronary artery calcification (CAC) is found frequently in advanced atherosclerotic lesions and could be a useful marker of them. We evaluated the prevalence of CAC in 49 stable renal transplant recipients and in 48 age- and gender-matched patients with chronic kidney disease (CKD) in stages 2-5 not requiring dialysis to assess risk factors associated with CAC. Computed tomography was used for CAC detection and quantification (CAC score). The prevalence of CAC was 43.8% in transplant recipients and 16.7% in CKD patients (p < 0.001). Transplant recipients with CAC were significantly older and had longer duration of CKD and/or dialysis than recipients without CAC. In contrast, the serum levels of fetuin A (an inhibitor of vascular calcification) and albumin were significantly lower in CKD patients with CAC than those without CAC. During the observation period (30 months), 30 patients, including 23 CKD patients, began dialysis, and 4 transplant recipients and 2 CKD patients died. Independent predictors of mortality were age, serum amyloid A and the CAC score. In conclusion, the examination and prevention of risk factors associated with atherosclerosis should be started at the beginning of renal failure.

Could the level of serum albumin be a method for assessing malnutrition in hemodialysis patients?

BACKGROUND: Traditionally, serum albumin concentration has been used for assessing the nutrition status of hemodialysis patients despite evidence that the level is also affected by inflammation and many other underlying disorders frequently present in these individuals. The authors evaluated albumin as a nutrition parameter, comparing it with more specific anthropometric parameters. METHODS: The study included a cohort of 271 patients. The analysis involved data obtained after patients entered the study (1994-2004). Anthropometric measurements included skinfolds, mid-arm circumference, mid-arm muscle circumference, percentage of body fat, body mass index, body height, and dry weight. Kt/V and normalized protein catabolic rate were also determined and laboratory analyses undertaken. RESULTS: Serum albumin was only weakly correlated with mid-arm circumference (r = 0.12), mid-arm muscle circumference (r = 0.15), and fat-free mass (r = 0.12). Common factor analysis of nutrition parameters uncovered latent variables, but serum albumin was not associated strongly with them. The sensitivity of albumin in detecting malnutrition was 24%, with a specificity of 88% and a predictive value of 74%. Graphic analysis showed disagreement in albumin levels with percentage of body fat and mid-arm muscle circumference. CONCLUSION: Serum albumin determination was shown to be a test with low sensitivity and specificity for evaluating malnutrition in hemodialysis patients. The values correlated weakly and showed graphic disagreement with anthropometric parameters. Therefore, methods that measure percentage of body fat and muscle mass should be used together or instead of serum albumin level for assessing the nutrition status of hemodialysis patients.

The predictive value of anthropometric parameters on mortality in haemodialysis patients.

BACKGROUND: Since protein-calorie malnutrition is a common factor influencing morbidity and mortality of haemodialysis patients, assessing their nutritional status is important. The aim of this study was to investigate the predictive value of anthropometric parameters on mortality and their interrelationship. METHODS: The study included a cohort of 242 patients. The analysis involved baseline data obtained during the first calendar year after the patients entered the study (1994-2001) and repeated measurements for up to 132 months of follow-up (until 2004). Anthropometric measurements were made during the winter season and included skinfolds, mid-arm circumference (MAC), body height and weight. The percentage of body fat (%fat) was calculated from triceps (TSF), biceps, subscapular and suprailiac skinfolds (Disease Outcomes Quality Initiative (DOQI) guidelines) and mid-arm muscle circumference (MAMC) from MAC and TSF. Body mass index (BMI), Kt/V, normalized protein catabolic rate (NPCR) and cardiovascular co-morbidity were also determined and laboratory analyses undertaken. RESULTS: Strong correlations were found among the anthropometric parameters. Extended Cox regression analysis selected %fat, MAC, MAMC and TSF in addition to age, ischaemic heart disease, congestive heart failure, Kt/V, haemoglobin, creatinine, albumin and NPCR as potential predictors of mortality. The same anthropometric parameters were found to be independent mortality predictors in corresponding models. The most predictive anthropometric factor was MAC. BMI was not a risk factor. CONCLUSION: Percentage of body fat, MAC, MAMC and TSF were independent predictors of mortality of haemodialysis patients, and MAC was the most predictive one.

Cyclosporine versus azathioprine therapy in high-risk idiopathic membranous nephropathy patients: A 3-year prospective study.

There is no consensus regarding the modality of therapy for idiopathic membranous nephropathy (IMN), especially for patients who did not react to treatment with cytotoxic drugs. This study followed prospectively for 3-year IMN patients who did not react to Ponticelli protocol comparing effects of 2-year course of cyclosporine (CsA) with azathioprine (Aza) treatment both with small doses of prednisolone. Twenty-three patients were randomly assigned to receive either cyclosporine at 3mg/kg per day (10 patients) or azathioprine at 1.5 to 2mg/kg (13 patients). Both groups were comparable regarding age, sex and renal function, except for proteinuria, which was significantly greater in CsA group (P=0.003). Similar rate of remission of nephrotic syndrome (NS) have been noted at the end of treatment (80% CsA versus 93% Aza). During last year, follow-up relapses of NS were more frequent in Aza group (5 versus 1). A fall in proteinuria was recorded in both groups during treatment, but it rose significantly in Aza group (1.5g/day versus 3.1g/day, P=0.04) and remained unchanged in CsA group (3.9g/day versus 4.1g/day) after treatment cessation. Renal function deteriorated in Aza group (sCr 120.5 versus 269.8µmol/L; P<0.01) and was stable in CsA group. In conclusion, CsA and steroids may be a very important option in the management of high-risk IMN patients. Long-term treatment is necessary for achievement of full therapeutic effect. Treatment with Aza did not have long-term benefits particularly regarding renal function preservation.

Serum amyloid-A rather than C-reactive protein is a better predictor of mortality in hemodialysis patients.

The most frequent cause of death in hemodialysis patients is cardiovascular disease with chronic inflammation being an epidemiologically proved risk factor. Many studies have shown C-reactive protein (CRP) as the strongest predictor of long-term mortality of hemodialysis patients, while other reports have indicated acute phase proteins as potential predictors of the mortality. The present study therefore aimed to evaluate the prevalence of chronic inflammation in hemodialysis patients and the role of acute phase proteins together with lipids and divalent ions for predicting mortality in hemodialysis patients. Chronic inflammation was defined, based on the serum level of high sensitive CRP > 8.4 mg/L and/or serum amyloid-A (SAA) > 8.9 mg/L. Acute phase proteins are defined as one whose plasma concentration increase (positive) or decreases (negative) by at least 25% during inflammation. High sensitive CRP and SAA were positive acute phase proteins measured, while albumin and fetuin-A, a calcification inhibitor, were selected as negative acute phase proteins. This prospective 36-month follow-up study included 130 patients (60 males and 70 females, aged 55.1 +/- 12.9 years) maintained by hemodialysis for 107.2 +/- 54.72 months at a Nephrology Clinic in Belgrade. The prevalence of chronic inflammation was 35.4% (46 patients). During the follow-up period, 24 patients (18.5%) died and 2 patients received transplants. In multivariate analysis, potential independent predictors of mortality in hemodialysis patients are hyperphosphatemia, hypoalbuminemia, and high SAA. Considering that assays for SAA are widely used, we propose that SAA is the best predictor for outcomes of end-stage renal disease.

[Influence of blood pressure control on maintenance of residual function in patients treated by haemodialysis].

INTRODUCTION: Residual renal function (RRF) in the patients treated by haemodialysis (HD) is associated not only with better volume and blood pressure control but also with better metabolic control.The condition of the cardiovascular system significantly affects RRF. OBJECTIVE: The aim of the study was to find if there was any association between blood pressure regulation and the achieved HD ultrafiltration in the first year of haemodialysis treatment and the maintenance of RRF. METHODS: In this retrospective study, 53 patients were analyzed in the period 1994-2002. Residual clearance of urea (RCU) was measured for the first time at the beginning of HD treatment, and for the second time one year later. Laboratory data and values of blood pressure as well as the achieved HD ultrafiltration were taken from the electronic database of the Nephrology Hospital. RESULTS: The value of RCU less than 1 ml/min was considered as the loss of RRF and, at the beginning of HD treatment, 14 patients (26.4%) had that result. The rise of mean arterial pressure (MAP) was associated in linear regression analysis with a drop of residual diuresis volume (beta = -0.28; p = 0.04), but there was no association with RCU. The patients with MAP > 105 mm Hg had RKU less than the patients with MAP < 105 mm Hg (t = 2.23; p = 0.03). The rise of the HD ultrafiiltration significantly affected the loss of RRF obtained by the linear regression analysis (beta = -0.44; p = 0.0001). CONCLUSION: The greater HD ultrafiltration is related to a drop of RCU values. Only prospective randomised trials with the use of multiple regression analysis could define a more precise association between hypertension and RKU.

Health-related quality of life, treatment efficacy, and hemodialysis patient outcome.

The aim of the study was to examine the influence of improved treatment of hemodialysis (HD) patients on their health-related quality of life (HrQoL) and to assess the predictive value of HrQoL dimensions on patient outcome. The prospective cohort study involved 102 HD patients, and their clinical and laboratory parameters and HD adequacy indices were followed from 2001 to 2007. HrQoL was measured using KDQOL-SF Version 1.3 in 2001, 2004, and 2007. During a six-year period, quality of HD and anemia treatment improved and resulted in significant increase of mean Kt/V (1.2-1.56) and hemoglobin levels (86.5-115.6 g/L). All four HrQoL dimensions (i.e., physical, mental health, kidney disease target issues, and patient satisfaction) remained unchanged, but significant improvement in several HrQoL physical health domains and the effects of kidney disease domain was found. Mortality rate decreased from 18.6% to 7.14% per year. Age was associated positively, but kidney disease target issue score negatively, with patient death. Improved HD adequacy and anemia treatment in HD patients were followed with maintenance of all four HrQoL dimensions unchanged over six years. Moreover, an improvement in several physical health domains and the effects of kidney disease domain was found. Age and kidney disease target issue appeared as significant predictors of patients' death.

Polyneuropathy in diabetic and nondiabetic patients on CAPD: is there an association with HRQOL?

BACKGROUND: It is well known that patients with uremia, as well as patients with diabetes mellitus, develop polyneuropathy. OBJECTIVES: The signs of polyneuropathy in diabetic and nondiabetic patients on continuous ambulatory peritoneal dialysis (CAPD) and their relation with age, duration of dialysis, biochemical parameters, dialysis adequacy, and health-related quality of life (HRQOL) were analyzed in the present study. PATIENTS AND METHODS: 65 CAPD patients (37 men, age 29-85 years, duration on dialysis 3 months to 14 years) were divided into two groups: group 1 was comprised of 20 diabetic patients (mean age 50.1+/-13.2 years); group 2 was comprised of 45 nondiabetic patients (mean age 62.3+/-9.7 years). Biochemical parameters, dialysis adequacy, and clinical signs were determined. Motor conduction velocity on the peroneal and tibial nerves and sensitive conduction velocity on the sural nerve were measured. The Kidney Disease Quality of Life Short Form (KDQOL-SF) was used to measure the CAPD patients' self-assessment of functioning and well-being using 4 component scores: physical component summary (PCS), mental component summary (MCS), kidney disease target issues, and patient satisfaction. RESULTS: Subjective symptoms were more intense in the diabetic patients and correlated with changes in peroneal and tibial distal motor latency (DML). Diabetic patients were significantly younger, had lower creatinine and higher glucose levels, and all analyzed pathological neurophysiological parameters were higher. Nondiabetic patients had prolonged latency of the F-wave on the peroneal nerve and the tibial nerve and reduced sensitive conduction velocity on the sural nerve. Significant correlations were found between the analyzed neurophysiological parameters and duration of dialysis and diabetes, glucose concentration, and dialysis adequacy in diabetic patients, and between neurophysiological parameters and age and dialysis adequacy in nondiabetic patients. Analysis of the 4 component scores of the KDQOL-SF revealed that diabetic patients had significantly better scores for PCS and MCS, which can be explained by their younger age. Patient satisfaction was worse in diabetic patients and correlated with duration of diabetes. In addition, significant correlations were established between PCS, MCS, and tibial DML (late neuropathic changes) in diabetic patients, and between MCS and tibial F-wave (early neuropathic changes) in nondiabetic patients. CONCLUSION: Polyneuropathy was significantly worse in diabetic than in nondiabetic patients on CAPD. DML on the tibial nerve correlated with glucose concentration, dialysis adequacy, PCS, and MCS in diabetic patients, whereas in nondiabetic patients, dialysis adequacy and azotemia correlated with F-waves on the peroneal nerve and the tibial nerve but MCS only with F-wave on the tibial nerve.

Nerve conduction studies and prediction of mortality in hemodialysis patients.

BACKGROUND: The electrophysiological aspects of uremic neuropathy have been studied extensively, but never for prediction of mortality. In order to assess the parameters of nerve conduction study (NCS) as predictors of mortality in hemodialysis patients, a post hoc analysis of a prospective observation study was made. METHODS: We examined conventional electrophysiological parameters (motor nerve conduction velocity [MCV], terminal latency [TL], and F wave latency of the peroneal nerve, as well as sensory nerve conduction velocity [SCV] of the sural nerve) in 75 nondiabetic patients. Hemodialysis modality (bicarbonate dialysis and biocompatible membranes), Kt/V, comorbidity (ischemic heart disease and congestive heart failure), and clinical and laboratory parameters were also evaluated. Survival was analyzed using the Cox proportional hazard model. RESULTS: SCV was significantly higher (t-test, p < 0.01) in the group of patients treated with polysulfone compared to those using cuprophane membranes. On the other hand, MCV significantly correlated with Kt/V (Pearson, r = 0.388; p < 0.01). Multivariate Cox regression revealed only MCV as a significant predictor of mortality in this group of hemodialysis patients (HR = 0.92; CI (0.86-0.99); p < 0.05). CONCLUSION: Only MCV was a significant mortality risk predictor among NCS parameters. This parameter correlates significantly with dialysis dose. SCV was related to the use of biocompatible membranes, indicating the complexity of polyneuropathy in dialysis patients.

Hepatitis B and hepatitis C virus infection and outcome of hemodialysis and kidney transplant patients.

AIM: A comparison of the outcome of hepatitis virus-positive and -negative kidney transplant and hemodialysis patients was the aim of this investigation. MATERIALS AND METHODS: The study involved 384 kidney transplant patients (67 HBsAg positive, 39 anti-HCV positive, 278 hepatitis negative), transplanted between 1987 and 2001, and 403 hemodialysis patients (128 HBsAg positive, 83 anti-HCV positive, 192 hepatitis negative) who had started hemodialysis and were referred to the kidney transplant waiting list during the same period. RESULTS: Hemodialysis patients were older than transplant patients. Comparison of the groups' survival rates, adjusted for patient age, showed that all kidney transplant patients survived longer than hemodialysis patients (p < 0.001). HBV infection had a negative impact on patient survival, especially in hemodialysis patients. HCV infection did not have a significant influence on patient survival. Cardiovascular disease was the main cause of death of all hemodialysis- and hepatitis-negative transplant patients. Liver failure was one of the leading causes of death in HBV-positive transplant patients. Mortality risk was higher for older patients, HBV-positive and -negative hemodialysis patients. CONCLUSIONS: Kidney transplantation offers longer survival for hepatitis-positive and -negative hemodialysis patients. HBV but not HCV infection had a negative impact on ESRD patient survival.

[Frequency of polyneuropathy signs in CAPD patients].

INTRODUCTION: It is well known that polyneuropathy has been an important cause of disability in patients maintained on hemodialysis as well as on peritoneal dialysis. The present study was aimed to analyze frequency and causes of polyneuropathy in patients on continuous ambulatory peritoneal dialysis (CAPD). MATERIAL AND METHODS: Sixty three CAPD patients (37 men), aged between 30 and 85 who were on dialysis from 1 to 290 months, were analyzed. Biochemical parameters and dialysis adequacy (KT/V) were determined. Motor conduction velocity (MCV) of peroneal and tibial nerve, and sensitive conduction velocity (SCV) on sural nerve were measured. RESULTS AND DISCUSSION: Biochemical parameters and dialysis adequacy were satisfactory in patients on CAPD. Polyneuropathy symptoms like paresthesias, pain, cramps and disability were found in more than 50% of patients. Over 80% of analyzed patients had pathological neurophysiological parameters: latency of F wave of n. peroneus and all analyzed parameters of n. tibialis, as the well as SCV on the sural nerve. A significant correlation was found between peroneal MCV and age, glycemia and serum creatinine; peroneal terminal latency (TL) and age; peroneal F wave and glycemia and serum urea; tibial MCV and glycemia; tibial F wave and glycemia, serum urea and KT/V. CONCLUSION: The most frequent signs of uremic polyneuropathy are reduced SCV on sural nerve and prolonged latency of F wave on peroneal and tibial nerves. Neurophysiological parameters on the lower extremities in patients on CAPD are in correlation with dialysis adequacy, glycemia and age.

An improvement in the outcome of acute renal failure.

BACKGROUND: Acute renal failure (ARF) requiring hemodialysis (HD) treatment is related to high mortality. The aim of this study was to analyze the influence of age, disease severity, and catabolism intensity on ARF outcome in patients requiring HD treatment during a 15-year period (1987-2001). METHODS: The retrospective, single-center study included 583 patients, 428 male, 155 female, age 49+/-15 years, treated by intermittent HD using cuprophane membranes with surface area of 1.3 m2. Liano's Acute Tubular Necrosis Individual Severity Score (ATNISS) score and Hypercatabolism Depuration Score (HDS) score were calculated to estimate disease severity and catabolism intensity in ARF patients. RESULTS: Average age of patients significantly increased during the 15-year period for more than one decade (44 to 55 years; p=0.0359), especially during the last five-year period (47+/-14.5 vs. 53+/-14.7, p=0.00015). Disease severity showed significant increase comparing periods 1992-1996 and 1997-2001 (ATNISS 0.385+/-0.197 vs. 0.437+/-0.208; p=0.00137), while catabolism intensity during these periods was similar (HDS 0.569+/-0.145 vs. 0.582+/-0.127; p=0.357). Despite the older and more severely ill population of ARF patients, mortality showed a sustained decrease during the 15-year period. Mortality in the period from 1987 to 1991 (49/83; 59%) was similar with the period 1992-1996 (chi2=0.44, p=0.5081), but significantly higher than in the period 1997-2001 (114/250; 45.6%; chi2=3.98, p = 0.0471). CONCLUSION: The results showed an improvement in the outcome of patients with ARF requiring HD treatment, despite increasing age, disease severity, and use of bioincompatible membranes.