Effects of percutaneous transluminal angioplasty and associated factors in access hand oxygenation in patients undergoing hemodialysis.

In hemodialysis (HD) patients with arteriovenous fistula (AVF), changes in systemic or peripheral tissue circulation occur non-physiologically via the presence of AVF; however, associations between blood flow and tissue oxygenation in the brain and access hand are uncertain. In this study, 85 HD patients with AVF were included and evaluated for changes in flow volume (FV) and regional oxygen saturation (rSO2) in the brain and hands with AVF before and after percutaneous transluminal angioplasty (PTA). Furthermore, we evaluated the factors that determine access hand rSO2 without stenosis after PTA. Brachial arterial FV increased after PTA (p < 0.001), and carotid FV decreased (p = 0.008). Access hand rSO2 significantly decreased after PTA (p < 0.001), but cerebral rSO2 did not significantly change (p = 0.317). In multivariable linear regression analysis of factors associated with access hand rSO2, serum creatinine (standardized coefficient: 0.296) and hemoglobin (standardized coefficient: 0.249) were extracted as independent factors for access hand rSO2. In conclusion, a decrease in access hand oxygenation and maintenance of cerebral oxygenation were observed throughout PTA. To maintain access hand oxygenation, it is important to adequately manage Hb level and maintain muscle mass, in addition to having an AVF with appropriate blood flow.

Intercorrelated variability in blood and hemodynamic biomarkers reveals physiological network in hemodialysis patients.

Increased intra-individual variability of a variety of biomarkers is generally associated with poor health and reflects physiological dysregulation. Correlations among these biomarker variabilities should then represent interactions among heterogeneous biomarker regulatory systems. Herein, in an attempt to elucidate the network structure of physiological systems, we probed the inter-variability correlations of 22 biomarkers. Time series data on 19 blood-based and 3 hemodynamic biomarkers were collected over a one-year period for 334 hemodialysis patients, and their variabilities were evaluated by coefficients of variation. The network diagram exhibited six clusters in the physiological systems, corresponding to the regulatory domains for metabolism, inflammation, circulation, liver, salt, and protein. These domains were captured as latent factors in exploratory and confirmatory factor analyses (CFA). The 6-factor CFA model indicates that dysregulation in each of the domains manifests itself as increased variability in a specific set of biomarkers. Comparison of a diabetic and non-diabetic group within the cohort by multi-group CFA revealed that the diabetic cohort showed reduced capacities in the metabolism and salt domains and higher variabilities of the biomarkers belonging to these domains. The variability-based network analysis visualizes the concept of homeostasis and could be a valuable tool for exploring both healthy and pathological conditions.

Association between Cerebral Oxygenation, as Evaluated with Near-Infrared Spectroscopy, and Cognitive Function in Patients Undergoing Hemodialysis.

INTRODUCTION: The prevalence of cognitive impairment in patients undergoing hemodialysis (HD) is higher than that in healthy controls. To date, studies on the association between cognitive function and cerebral oxygenation in these patients are limited. Therefore, in this study, we aimed to cross-sectionally investigate the association between cognitive assessment scores and clinical factors, including cerebral oxygenation, in patients undergoing HD. METHODS: In this observational study, 193 HD patients were included. Cerebral regional oxygen saturation (rSO2) was monitored using an INVOS 5,100c oxygen saturation monitor. Poor cognition was defined as a Mini-Mental State Examination (MMSE) score ≤23. We analyzed the association between MMSE score and clinical factors, including cerebral rSO2. RESULTS: MMSE score in HD patients included in this study was 26.8 ± 3.3. There were 164 patients (85%) with MMSE score ≥24 and 29 patients (15%) with an MMSE score ≤23. In the patients with MMSE score ≥24, cerebral rSO2 (53.8% ± 8.3%) was significantly higher than that in patients with MMSE score ≤23 (49.5% ± 9.8%; p = 0.013). Multivariable linear regression analysis was performed using the following confounding factors: age, mean blood pressure, cerebral rSO2, HD duration, ultrafiltration rate, hemoglobin, serum Cr, serum calcium, serum phosphate, total cholesterol, high-density lipoprotein cholesterol levels, serum albumin, presence of diabetes mellitus or chronic glomerulonephritis, history of comorbid cardiovascular or cerebrovascular disease, and use of renin-angiotensin-aldosterone system inhibitors or vitamin D analogs. MMSE score was independently and significantly associated with age (standardized coefficient: -0.244) and cerebral rSO2 (standardized coefficient: 0.180). CONCLUSIONS: MMSE score was independently associated with age (negative effect) and cerebral rSO2 (positive effect) in this cross-sectional study. Further prospective studies are needed to clarify whether maintaining cerebral oxygenation prevents the deterioration of cognitive function in patients undergoing HD.

Estimation of homeostatic dysregulation and frailty using biomarker variability: a principal component analysis of hemodialysis patients.

Increased intraindividual variability in several biological parameters is associated with aspects of frailty and may reflect impaired physiological regulation. As frailty involves a cumulative decline in multiple physiological systems, we aimed to estimate the overall regulatory capacity by applying a principal component analysis to such variability. The variability of 20 blood-based parameters was evaluated as the log-transformed coefficient of variation (LCV) for one year's worth of data from 580 hemodialysis patients. All the LCVs were positively correlated with each other and shared common characteristics. In a principal component analysis of 19 LCVs, the first principal component (PC1) explained 27.7% of the total variance, and the PC1 score exhibited consistent correlations with diverse negative health indicators, including diabetes, hypoalbuminemia, hyponatremia, and relative hypocreatininemia. The relationship between the PC1 score and frailty was subsequently examined in a subset of the subjects. The PC1 score was associated with the prevalence of frailty and was an independent predictor for frailty (odds ratio per SD: 2.31, P = 0.01) using a multivariate logistic regression model, which showed good discrimination (c-statistic: 0.85). Therefore, the PC1 score represents principal information shared by biomarker variabilities and is a reasonable measure of homeostatic dysregulation and frailty.

Aging and death-associated changes in serum albumin variability over the course of chronic hemodialysis treatment.

BACKGROUND: Several epidemiological studies have demonstrated associations between variability in a number of biological parameters and adverse outcomes. As the variability may reflect impaired homeostatic regulation, we assessed albumin variability over time in chronic hemodialysis (HD) patients. METHODS: Data from 1346 subjects who received chronic HD treatment from May 2001 to February 2015 were analyzed according to three phases of HD treatment: post-HD initiation, during maintenance HD treatment, and before death. The serum albumin values were grouped according to the time interval from HD initiation or death, and the yearly trends for both the albumin levels and the intra-individual albumin variability (quantified by the residual coefficient of variation: Alb-rCV) were examined. The HD initiation and death-associated changes were also analyzed using generalized additive mixed models. Furthermore, the long-term trend throughout the maintenance treatment period was evaluated separately using linear regression models. RESULTS: Albumin levels and variability showed distinctive changes during each of the 3 periods. After HD initiation, albumin variability decreased and reached a nadir within a year. During the subsequent maintenance treatment period (interquartile range = 5.2-11.0 years), the log Alb-rCV showed a significant upward trend (mean slope: 0.011 ± 0.035 /year), and its overall mean was -1.49 ± 0.08 (equivalent to an Alb-rCV of 3.22%). During the 1-2 years before death, this upward trend clearly accelerated, and the mean log Alb-rCV in the last year of life was -1.36 ± 0.17. The albumin levels and variability were negatively correlated with each other and exhibited exactly opposite movements throughout the course of chronic HD treatment. Different from the albumin levels, albumin variability was not dependent on chronological age but was independently associated with an individual's aging and death process. CONCLUSION: The observed upward trend in albumin variability seems to be consistent with a presumed aging-related decline in homeostatic capacity.

Variability of laboratory parameters is associated with frailty markers and predicts non-cardiac mortality in hemodialysis patients.

BACKGROUND: The levels of many laboratory parameters are associated with the outcomes of dialysis patients, but the significance of their variability has not been well studied. METHODS: A total of 384 patients receiving stable hemodialysis treatment during 2002 were followed up for mortality until the end of 2013. The within-patient coefficients of variation (CV) were calculated for 13 laboratory parameters from 1 year of data. We defined variability as CV and analyzed the survival of the patients according to the baseline CV values of each parameter by proportional hazard modeling. RESULTS: During the 11-year observation period, 125 patients died. Higher CV levels for eight parameters, namely, blood urea nitrogen (BUN), sodium, hemoglobin, creatinine, total protein, albumin, potassium and phosphate, were significantly associated with all-cause mortality. The adjusted hazard ratios for a high BUN-CV (>15 %) and a high Na-CV (>1.3 %) against a lower CV were 1.92 (95 % CI 1.31-2.81) and 1.95 (1.36-2.80), respectively. The increased mortality risk associated with each variability was attributed to excess non-cardiac deaths. The CV values of most parameters were correlated with each other and often exhibited negative associations with age, diabetes, and mobility as well as the levels of hemoglobin, albumin, creatinine, Na, the protein catabolic rate, and the creatinine generation rate. Therefore, a high variability was generally associated with frailty-related adverse prognostic factors. CONCLUSIONS: The variability of several blood parameters had a significant impact on all-cause and non-cardiac mortality. The levels of the variabilities were most likely related to poor physical conditions of the patients.

Efficacy of once-weekly intravenous administration of epoetin-beta as a maintenance treatment for anemia in Japanese hemodialysis patients: a multicenter, open-label clinical study.

Epoetin-beta is extremely useful as a drug for treating anemia in hemodialysis (HD) patients and is widely used for that purpose. The aim of this study was to determine whether once-weekly intravenous administration of epoetin-beta is as effective in maintaining hemoglobin (Hb) concentration as the same weekly dose administered 2 or 3 times per week as maintenance treatment of anemia in HD patients. The subjects were stable HD patients who had been receiving HD for at least 12 months. Using a fixed weekly dose of 3000 or 6000 IU of epoetin-beta, this study evaluated maintenance of improvement of anemia by comparing Hb concentration in the study period (once-weekly) with Hb concentration in the prestudy period (2 or 3 times per week). Of the 112 patients treated with epoetin-beta, 111 patients (full analysis set; 3000 IU, 52 patients; 6000 IU, 59 patients) were evaluated, after excluding one patient whose dose was changed immediately before study initiation. The change in the Hb concentration was maintained within +/-1.5 g/dL in 89.2% of patients (3000 IU, 88.5%; 6000 IU, 89.8%). The mean Hb concentration was 10.42 +/- 0.73 g/dL at study initiation and 10.14 +/- 1.00 g/dL at study completion. Adverse reactions occurred in 9.8% of patients (11 out of 112 patients). The main adverse reactions were malaise and increased blood pressure. Once-weekly intravenous administration of epoetin-beta is useful as maintenance treatment of anemia in HD patients and may be a treatment option.

Possible interactive effects of demographic factors and stress coping mechanisms on depression and anxiety in maintenance hemodialysis patients.

OBJECTIVE: The aim of this study was to assess the possible interactive effects of age, sex, duration of hemodialysis (HD), educational and income levels, and stress coping mechanisms on depression and anxiety in patients on maintenance HD. METHODS: Uremic patients (N=416), regularly undergoing HD for more than 1 year, who did not have apparent cerebrovascular disease or serious intellectual impairment, were investigated. The interactive effects of age, sex, duration of HD, and educational and income levels, in relation to stress coping mechanisms, on depression or anxiety were assessed by hierarchical multiple regression analyses. RESULTS: Regression lines illustrating significant (P<.05) interactions were constructed. The decrease in depression accompanying the increase in task-oriented stress coping was greater in highly educated patients than it was in the other patients. Anxiety levels decreased when patients had both high income and demonstrated a range of task-oriented stress coping mechanisms. For patients undergoing HD for long duration, or with a relatively high income, the decrease of depression and anxiety accompanying a decrease of emotion-oriented stress coping was greater, as compared with other patients. The decrease of depression accompanying an increase of avoidance-oriented stress coping was greater in patients with low income and in older patients than it was in the other patients. CONCLUSIONS: These findings may lead to the development of specific and focused interventions for depression or anxiety in maintenance HD patients.

Possible variances of blood urea nitrogen, serum potassium and phosphorus levels and interdialytic weight gain accounted for compliance of hemodialysis patients.

OBJECTIVES: The aim of this study was to assess the possible variances of blood urea nitrogen (BUN), serum potassium (SK) and serum phosphorus (SPO(4)) levels and interdialytic weight gain (IWG) accounted for compliance of uremic patients on hemodialysis (HD). METHODS: BUN, SK and SPO(4) levels and IWG of uremic patients (n=310) regularly undergoing three HD sessions per week for more than 1 year in Japan were assessed. Patients suffering from problems influencing dietary intake and those with malnutrition were excluded. The variances accounted for self-efficacy for health-related behavior and avoidance-oriented coping (AOC) with stress were assessed by hierarchical multiple regression analyses. RESULTS: BUN and SPO(4) levels were not significantly (P<.05) associated with self-efficacy or AOC. SK levels and IWG were significantly (P<.05) associated with self-efficacy and/or AOC. The variances of SK levels and IWG accounted for self-efficacy and/or AOC, independent of age, sex, duration of HD and facilities, were 1.6% and 5.0%, respectively. CONCLUSIONS: Although the variances of SK levels and IWG accounted for self-efficacy and/or AOC were rather small, the significance of their relationships may suggest that intervention for self-efficacy or AOC could improve compliance and reduce SK levels and IWG of uremic patients on HD.

Clinical and psychological aspects of restless legs syndrome in uremic patients on hemodialysis.

BACKGROUND: The pathogenesis of restless legs syndrome (RLS) is still unclear. The purpose of this study is to determine relationships of the presence of RLS in uremic patients regularly undergoing hemodialysis (HD) with demographic, clinical, and psychological factors. METHODS: In 490 uremic patients on HD therapy in Japan, RLS was diagnosed based on diagnostic criteria established by the International Restless Legs Syndrome Study Group. Data were compared between patients with and without RLS. RESULTS: There were univariately significant (P < 0.05) differences in serum phosphorus levels, anxiety levels determined using the Hospital Anxiety and Depression Scale, and degrees of emotion-oriented and avoidance-oriented coping determined using the Coping Inventory for Stressful Situations. In multivariate analyses, low hemoglobin levels, high serum phosphorus levels, high anxiety levels, and a great degree of emotion-oriented coping were independently related to the presence of RLS in uremic patients on HD therapy, with statistical significance (P < 0.05). CONCLUSION: Hyperphosphatemia, anxiety, and a great degree of emotion-oriented coping with stress were independently related to the presence of RLS in uremic patients on HD therapy. The pathogenesis of RLS seems to involve more than one mechanism, which leads to restless legs as the final common pathway. These findings may provide new clues to the pathogenesis of RLS.

Interactions among a stressor, self-efficacy, coping with stress, depression, and anxiety in maintenance hemodialysis patients.

The authors' purpose in this study was to assess the interactive effects of stressors, coping with stress, and self-efficacy on depression and anxiety in maintenance hemodialysis (HD) patients. Patients (n = 453) undergoing HD for more than 1 year in Japan were investigated. The regression lines illustrating significant (p < .05) interactions predict that itching HD patients with low self-efficacy will be more depressive and anxious than nonitching patients. In HD patients who report a high degree of emotion-oriented coping, itching patients will be more anxious than nonitching patients. These new findings may lead to the development of specific and focused interventions for depression or anxiety in maintenance HD patients.