Hydrogenology
Hydrogenology editorial study record

Reduction of oxidative stress and CRP levels in hemodialysis patients by hydrogen gas inhalation

Sokawa S, Matsuura A, Suga Y, Sokawa Y, Kojima T, Nakamura H. · Journal of Japanese Society for Dialysis Therapy. 2021;54(9):433–441.

HumanInhaled H₂Published 2021
Study record, not medical adviceThis page reports one source and Hydrogenology’s source-text extraction. It does not establish that molecular hydrogen is effective, safe or appropriate for any person. Human, animal and laboratory evidence must not be treated as equivalent.
Source and classification

What kind of evidence is this?

Evidence stream

Human

Reported design

Uncontrolled before-during-after pilot study

Research topic

Kidney and urinary health

Administration classification

Inhaled H₂

Study result signal

Not reported in this record.

Outcome type

Not reported in this record.

Reported in the source

Methods at a glance

Population or model

Adults receiving maintenance hemodialysis.

Sample

6 patients were characterized at baseline; the hydrogen intervention analysis included 5 with elevated oxidative stress.

Duration

Six dialysis sessions over 2 weeks, with follow-up after inhalation stopped.

Intervention

Hydrogen inhalation started 5–10 minutes before dialysis and continued until 5–10 minutes after dialysis for six consecutive sessions over 2 weeks.

Hydrogen form

High-purity H₂ gas alone — not Brown's gas.

H₂ specification

99.99% H₂ at 500 mL/min through a nasal route.

H₂ flow

499.95 mL/min H₂, calculated from 500 mL/min total source-gas flow × 99.99% H₂.

O₂ delivered with H₂

No supplemental O₂ was reported; 0.01% non-H₂ remainder was not identified and is not assumed to be oxygen.

Comparator

Participants' own pre-intervention and post-withdrawal measurements; no parallel control group.

Reported, not endorsed

Outcomes and reported result

Outcomes measured

d-ROMs oxidative-stress measure, biological antioxidant potential, CRP and dialysis parameters.

Reported result

Mean d-ROMs decreased from 433 to 395 U.CARR and CRP from 1.05 to 0.61 mg/dL during inhalation; values later reached 349 U.CARR and 0.42 mg/dL after cessation. Antioxidant capacity did not show a confirmed effect.

Results-extraction completeness

The complete free J-STAGE full article, Japanese methods, figures and English abstract were checked.

A reported association, difference or mechanism is not automatically a clinical benefit. Null findings, outcome type, study design and precision all matter.

Interpretation limits

Cautions and applicability

Design and reporting cautions

Only five treated patients, no parallel control and repeated measurements. Continued changes after withdrawal make causal attribution uncertain. The article does not establish clinical benefit or improved dialysis outcomes.

Applies directly to

Maintenance hemodialysis patients in this small Japanese pilot.

Preliminary appraisal framework

Not reported in this record.

Preliminary risk-of-bias status

Not reported in this record.

Appraisal rationale

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.

Provenance

Sources and record status

Identifiers

OpenAlex ID: W3204512112 · DOI: 10.4009/jsdt.54.433

Publisher access

Free full article on J-STAGE.

Extraction basis

J-STAGE publisher full article; full-text extraction checked 8 August 2026.

Record revision

2026-08-10