Hemodialysis employing molecular hydrogen (H₂) enriched dialysis solution may improve dialysis related fatigue through impact on energy metabolism
Nakayama M, Watanabe K, Sato E, et al. · Scientific Reports. 2025;15:5039.
What kind of evidence is this?
Human
Prospective single-center uncontrolled before-and-after observational study
Kidney and urinary health
Other forms
Not reported in this record.
Not reported in this record.
Methods at a glance
Adults receiving maintenance hemodialysis at one outpatient center.
92 consented; 81 completed 12 months and were analyzed: 25 with fatigue reducing activity, 24 with fatigue without activity reduction and 32 without fatigue.
Three sessions/week, 4–5 hours/session, followed for 12 months.
All clinic patients switched from standard hemodialysis to an electrolyzed-water hemodialysis system containing dissolved H₂.
H₂ dissolved in dialysis solution — not inhaled, not swallowed and not Brown's gas.
Final dialysate contained 70–130 ppb dissolved H₂; composition, electrolytes and pH otherwise matched standard dialysate.
Not applicable — H₂ was dissolved in dialysate, not delivered as inhaled gas.
No O₂ was co-delivered as a distinct intervention.
Participants' standard-hemodialysis baseline; no concurrent control group.
Outcomes and reported result
Fatigue numerical rating scales, body composition, biocompatibility markers, uremic toxins and exploratory metabolomics.
In the 25-person fatigue-with-activity-reduction group, dialysis-day fatigue fell from 5.56±1.33 to 3.56±2.47 at 12 months (within-group p<0.05); no change occurred in the other baseline groups. HD-free-day fatigue was not significantly changed overall. NETosis markers were null; metabolomic findings were exploratory and based on 35 selected samples.
The complete Scientific Reports article, participant flow, dialysate concentration, all fatigue time points, body-composition, null biocompatibility results, metabolomics, funding and competing interests were checked.
A reported association, difference or mechanism is not automatically a clinical benefit. Null findings, outcome type, study design and precision all matter.
Cautions and applicability
No concurrent control, universal clinic-wide switch, subjective fatigue, older single-center cohort and regression to the mean are major limitations. The metabolomic pathway interpretation is exploratory. Eleven consented patients did not complete follow-up. Tohoku University Hospital funding was reported; authors declared no competing interests.
Maintenance-hemodialysis patients in this outpatient program; not evidence for drinking or inhaling H₂.
Not reported in this record.
Not reported in this record.
Not reported in this record.
No single-study GRADE certainty rating is assigned. Certainty is assessed by important outcome across a complete eligible evidence set, not by attaching a final grade to one source.
Sources and record status
PMID: 39934143 · DOI: 10.1038/s41598-025-88827-2
Open-access full article on Scientific Reports and PMC.
Scientific Reports publisher and PMC full articles plus PubMed record; full-text and article-status check completed 8 August 2026.
2026-08-10