Hydrogenology editorial study record

Hydrogen-oxygen mixture inhalation as an adjunctive treatment to home-based exercise in older patients with knee osteoarthritis

Wang C et al. · Front Pharmacol. 2025;16:1505922.

HumanInhaled H₂Published 2025

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

Open-label randomized trial with blinded endpoint assessment

Research topic

Musculoskeletal and pain research

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

Older adults with knee osteoarthritis living in a retirement community

Sample

121 participants; mean age 81.2 years; 80.2% women

Duration

Inhalation for 60 minutes daily during the first 2 weeks; follow-up through week 12

Intervention

Nasal inhalation of 2.0 L/min H₂ plus 1.0 L/min O₂ for 60 minutes daily, alongside home exercise

Hydrogen form

Brown’s gas / oxyhydrogen — H₂ and O₂ co-delivered.

H₂ specification

Generator output was 2:1 H₂:O₂, approximately 66.7% H₂ and 33.3% O₂.

H₂ flow

2,000 mL/min H₂, directly reported.

O₂ delivered with H₂

1,000 mL/min O₂, directly reported.

Comparator

The same 12-week home exercise and health-education program without gas inhalation

Reported, not endorsed

Outcomes and reported result

Outcomes measured

WOMAC, chair stand, timed up-and-go, quality of life, exercise adherence, inflammatory markers and adverse events

Reported result

The week-12 between-group WOMAC difference was not significant and did not reach the minimum clinically important difference. Temporary early differences were reported; sustained objective-function and quality-of-life benefits were not established.

Results-extraction completeness

Gas flow, full methods, results, funding and conflicts checked in the open-access full text; independent appraisal remains incomplete.

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

Open-label adjunctive study without placebo gas. The principal week-12 comparison was null and below the clinical-importance threshold; early effects were not sustained. Public funding was reported.

Applies directly to

Very old adults with knee osteoarthritis participating in a home-exercise program.

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

PMID: 39950118 · DOI: 10.3389/fphar.2025.1505922

Publisher access

Open-access full text is available through PMC and Frontiers.

Extraction basis

Open-access PMC and Frontiers full texts plus PubMed record.

Record revision

2026-08-10

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