Improvement of the fraction of human mercaptalbumin on hemodialysis treatment using hydrogen-dissolved hemodialysis fluid: a prospective observational study

Application of Electrolyzed Hydrogen Water for Management of Chronic Kidney Disease and Dialysis Treatment-Perspective View

Chronic kidney disease (CKD), which is globally on the rise, has become an urgent challenge from the perspective of public health, given its risk factors such as end-stage renal failure, cardiovascular diseases, and infections. The pathophysiology of CKD, including dialysis patients, is deeply associated with enhanced oxidative stress in both the kidneys and the entire body. Therefore, the introduction of a safe and widely applicable antioxidant therapy is expected as a measure against CKD. Electrolyzed hydrogen water (EHW) generated through the electrolysis of water has been confirmed to possess chemical antioxidant capabilities. In Japan, devices producing this water have become popular for household drinking water. In CKD model experiments conducted to date, drinking EHW has been shown to suppress the progression of kidney damage related to hypertension. Furthermore, clinical studies have reported that systemic oxidative stress in patients undergoing dialysis treatment using EHW is suppressed, leading to a reduction in the incidence of cardiovascular complications. In the future, considering EHW as one of the comprehensive measures against CKD holds significant importance. The medical utility of EHW is believed to be substantial, and further investigation is warranted.

Association Between the Redox State of Human Serum Albumin and Exercise Capacity in Patients With Cardiac Disease

The redox state of human serum albumin (HSA) is reported to be an oxidative stress biomarker; however, its clinical use in cardiac disease has not yet been examined. This study aimed to investigate the relation between the redox state of HSA and exercise capacity, which is a robust prognostic factor, in patients with cardiovascular disease. This cross-sectional study included outpatients with cardiac disease. Exercise capacity was assessed by peak oxygen consumption (peakVO₂) measured using symptom-limited cardiopulmonary exercise testing. The high-performance liquid chromatography postcolumn bromocresol green method was used to part HSA into human nonmercaptalbumin (oxidized form) and human mercaptalbumin (HMA, reduced form). The fraction of human mercaptalbumin found in HSA (f[HMA]) was calculated as an indicator of the redox state of HSA. The association between peakVO₂ and f(HMA) was examined using the Spearman correlation coefficient and multivariate linear regression analysis. A total of 70 patients were included (median age 76 years; 44 men; median peakVO₂ 15.5 ml/kg/min). The f(HMA) was positively correlated with peakVO₂ (r = 0.38, p <0.01). Even after controlling for potential confounders, this association remained in the multivariate linear regression analysis (standardized beta = 0.24, p <0.05). We found a positive association between f(HMA) and peakVO₂, independent of potential confounders in patients with cardiac disease, suggesting that f(HMA) may be a novel biomarker related to exercise capacity in cardiac disease. Longitudinal studies are required to further examine the prognostic capability of f(HMA), the responsiveness to clinical intervention, and the association between f(HMA) and cardiac disease.

Impact of hemodialysis solutions containing different levels of molecular hydrogen (H2) on the patient-reported outcome of fatigue

Background

Reportedly, dialysis solutions containing molecular hydrogen (H2) might ameliorate patient-reported fatigue in hemodialysis (HD) patients. However, it is unknown whether its impact might differ with different H2 levels.

Method

This single-arm, prospective observational study examined 105 patients on chronic HD (62 males; mean age, 66 years; mean HD duration, 117 months). All patients were originally treated with an HD solution with 47 ppb (mean) H2 for more than 12 months, followed by an HD solution with 154 ppb (mean) H2 for 8 weeks. Baseline and changes in subjective fatigue status rated on a numerical rating scale (NRS) were assessed before the start of the study (baseline) and 8th week of the study.

Results

Patients were classified into three groups according to the presence of subjective fatigue at baseline: Group A (15.2%), presence of fatigue on both HD and HD-free days; Group B (28.6%), fatigue only on HD days; and Group C (56.2%), freedom from fatigue. In Group A, NRS scores during the 8-week period were significantly decreased as compared with 0 week, at the 4th and 8th week on HD days, and at the 8th week on HD-free day, respectively. While no consistent changes were found in other groups. At the 8th week, 64 patients (61%) presented absence of or decrease in the NRS score of fatigue, while the rest of patients did not present the decrease in NRS (the non-improved: 39%). Regarding the factors related to the non-improved, prescription of antihypertensive agents was a significant independent risk factor by multivariate analysis, indicating the possible involvement of excess fall in blood pressure (BP) in those patients.

Conclusion

Amelioration of the patient-reported outcome of fatigue might be influenced by H2 levels in the HD solution, and the optimal H2 level in the dialysate needs to be elucidated in consideration of clinical type of fatigue and BP control status.

Amelioration of fatigue in chronic dialysis patients with dialysis solution employing electrolyzed water containing molecular hydrogen (H2) and its association with autonomic function balance

Background

Enhanced oxidative stress is involved with fatigue in hemodialysis (HD) patients. Molecular hydrogen (H2) could improve the redox status. Thus, the study examines whether HD solution rendered by electrolyzed water containing H2 (E-HD) could impact the fatigue and autonomic balance of patients.

Methods

This single-arm, prospective observational study examined 95 patients on chronic HD (54 males; mean age and HD duration; 71.4 years and 10.6 years). Fatigue status on HD and HD-free days was compared between control HD (CHD) and 8 weeks after commencement of E-HD, using a visual analog scale (VAS) and an original scale. Autonomic balance was analyzed with the degree of activities of the sympathetic and parasympathetic nervous system via frequency analysis of a continuous beat interval.

Results

Patients were classified into three groups according to the presence of subjective fatigue during the period of CHD: Group A (40.0%), fatigue only on HD days; Group B (11.6%), presence of fatigue on both HD and HD-free days; and Group C (48.4%), freedom from fatigue. During the 8-week observation period of E-HD, VAS scores were significantly decreased on HD days in Group A, while Group B showed no significant changes in VAS on HD days, but significant decreases on HD-free days. No consistent changes were found in Group C. Significant increases in percentages of patients who reported absence of fatigue were seen in Group A on HD days and in Group B on HD-free days in week 8. Regarding changes in autonomic balance parameters after E-HD commencement, a positive correlation was identified between changes in VAS and autonomic balance in Group A.

Conclusion

E-HD may ameliorate fatigue in patients with subjective symptoms on HD and HD-free days. The influence of autonomic balance by E-HD and its impact on fatigue needs to be elucidated.

Human Nonmercaptalbumin Is a New Biomarker of Motor Function

The ratio of human nonmercaptalbumin (HNA) and reduced albumin (HMA) may be a new marker for oxidative stress. Locomotive syndrome (LS) is reduced mobility due to impairment of locomotive organs. We investigated whether the HNA/HMA ratio could be a new biomarker of LS. This study included 306 subjects (mean age 64.24 ± 10.4 years) who underwent LS tests, grip strength, walking speed, and tests for HNA and HMA. Oxidative stress was measured by the ratio of HMA (f(HMA) = (HMA/(HMA + HNA) × 100)), and the subjects were divided into normal (N group; f[HMA] ≥ 70%) and low (L group; f[HMA] < 70%) groups. There were 124 non-elderly (<65 years) and 182 elderly subjects (≥65 years). There were no significant differences in LS, grip strength, and walking speed between the L and N groups in the non-elderly subjects. However, significant differences were found in the elderly subjects. In logistic regression analysis, there was an association between f(HMA) and the LS severity at older ages. LS in the elderly is associated with a decline in HMA and, thus, an increase in oxidative stress. Thus, f(HMA) is a new biomarker of LS.

Human serum albumin redox state is associated with decreased renal function in a community-dwelling population

The redox state of human serum albumin (HSA) has attracted interest as a possible biomarker for oxidative stress (OS) in humans. Although previous studies on this topic have taken only clinical settings into consideration, evidence of its efficacy in nonclinical settings remains to be established. The present study aimed to examine and validate the relationship between HSA redox state and renal function in a rural Japanese population. We analyzed two independent data sets from health checkup programs conducted in 2013 and 2016: one for discovery ( n = 267) and the other for replication ( n = 367). The fraction of human mercaptalbumin (HMA) to total HSA [f(HMA)] was determined using our revised method of high-performance liquid chromatography with post-column bromocresol green. The estimated glomerular filtration rate (eGFR) was calculated based on each individual's serum creatinine value, sex, and age. Adjustment for potential confounders revealed positive associations of fraction of human mercaptalbumin [f(HMA)] with eGFR in the discovery and replication analyses ( P < 0.001 and P = 0.03, respectively). Multivariate logistic regression analyses demonstrated significant inverse associations between renal dysfunction (defined as eGFR < 60 ml·min^-1·1.73 m^-2) and f(HMA) by a factor of 0.50 and 0.65 (confidence intervals of 0.26-0.91 and 0.37-1.00), respectively, with a unit of 10% f(HMA). Our results indicate that HSA redox state is consistently associated with renal dysfunction in both clinical and nonclinical settings.

Novel haemodialysis (HD) treatment employing molecular hydrogen (H2)-enriched dialysis solution improves prognosis of chronic dialysis patients: A prospective observational study

Recent studies have revealed unique biological characteristics of molecular hydrogen (H₂) as an anti-inflammatory agent. We developed a novel haemodialysis (E-HD) system delivering an H₂ (30-80 ppb)-enriched dialysis solution by water electrolysis, and conducted a non-randomized, non-blinded, prospective observational study exploring its clinical impact. Prevalent chronic HD patients were allocated to either the E-HD (n = 161) group or the conventional HD (C-HD: n = 148) group, and received the respective HD treatments during the study. The primary endpoint was a composite of all-cause mortality and development of non-lethal cardio-cerebrovascular events (cardiac disease, apoplexy, and leg amputation due to peripheral artery disease). During the 3.28-year mean observation period, there were no differences in dialysis parameters between the two groups; however, post-dialysis hypertension was ameliorated with significant reductions in antihypertensive agents in the E-HD patients. There were 91 events (50 in the C-HD group and 41 in the E-HD group). Multivariate analysis of the Cox proportional hazards model revealed E-HD as an independent significant factor for the primary endpoint (hazard ratio 0.59; [95% confidence interval: 0.38-0.92]) after adjusting for confounding factors (age, cardiovascular disease history, serum albumin, and C-reactive protein). HD applying an H₂-dissolved HD solution could improve the prognosis of chronic HD patients.

Oxidized human serum albumin as a possible correlation factor for atherosclerosis in a rural Japanese population: the results of the Yakumo Study

Background

The effect of the redox state of human serum albumin (HSA) on the antioxidant properties of the entire body has been a focus of recent research. The usefulness of HSA redox state as a biomarker for reducing oxidative stress has been investigated in clinical settings; however, evidence for its significance as a health index in non-clinical settings is yet to be established. This study aimed to examine the associations between HSA redox state and the atherosclerotic indices of carotid intima-media thickness (IMT) and plaque formation in a rural Japanese population.

Methods

We conducted a cross-sectional study as part of a health check-up program in the rural area of Hokkaido, Japan, at the end of August 2013. A total of 281 residents (124 men and 157 women) were included in the final analysis. Lifestyle-related data were obtained through a self-reported questionnaire, and ultrasound examinations were performed to measure IMT and determine plaque formation. The high-performance liquid chromatography postcolumn bromocresol green method was used to separate HSA into human nonmercaptalbumin and human mercaptalbumin (HMA).

Results

We found a significant negative relationship between the fraction of HMA [f(HMA)] and IMT (standardized β = − 0.132, p = 0.03). Moreover, f(HMA) was significantly associated with plaque formation (p < 0.01) with an odds ratio of 0.89 (95% confidence interval, 0.81–0.97) for every 10% increment in f(HMA).

Conclusions

We found that the HSA redox state, as determined by f(HMA), was associated with atherosclerotic indices in Japanese subjects. These results suggest that the HSA redox state indicates the risk of developing atherosclerosis.