Preliminary Effects of Hydrogen-Oxygen Inhalation on Nodule Size, IL-6, and Neutrophils in Patients with Small Pulmonary Nodules
Wei X, Zhang W, Li Y, Sha X, Yi H, Cui C. · Drug Design, Development and Therapy. 2026;20:605134. Published 8 July 2026.
Study at a glance
In 59 older adults with small lung nodules, a two-week hydrogen–oxygen course was compared with air. At three months, the hydrogen group had a small average reduction in nodule diameter and lower levels of some inflammation markers. The size change was close to ordinary CT measurement variation, and the groups also received different oxygen concentrations. The study did not measure cancer prevention or long-term clinical benefit. Registration dates and some baseline values are inconsistent within the report.
Human
Adults aged 60–75 with a solitary pulmonary nodule no larger than 10 mm.
4 hours/day, split into two 2-hour sessions, for 14 days; outcome follow-up at 3 months. · Approximately 66.6% H₂ and 33.3% O₂, total 3,000 mL/min. Approximately 2,000 mL/min H₂ is calculated from the reported mixture, not a measured inhaled dose. Actual inspired H₂ concentration was not measured separately from generated gas.
4 hours/day in two 2-hour sessions for 14 days; outcomes assessed at 3 months.
Mean nodule diameter: hydrogen: 3.97 to 3.33 mm; reduction 0.64 mm, 95% CI 0.20 to 1.08; within-group p = 0.006; comparator: 4.29 to 4.19 mm; reduction 0.10 mm, 95% CI −0.32 to 0.52; within-group p = 0.641; Post-treatment diameter: 3.33 versus 4.19 mm; reported p < 0.001. The confidence intervals above describe changes within each group, not the difference between groups. IL-6: hydrogen: 5.04 to 3.68 pg/mL; comparator: 5.21 to 5.05 pg/mL; between group: Post-treatment p < 0.001. Neutrophils: hydrogen: 3.77 to 2.63 × 10^9/L; comparator: 4.10 to 3.85 × 10^9/L; between group: Post-treatment p = 0.001. CRP and Mayo malignancy risk score: between group: Post-treatment p = 0.239 and p = 0.946 respectively; not significant.
Small single-centre trial with three-month follow-up and no clinical cancer endpoint. The 0.64 mm within-group diameter change is close to approximately 0.6 mm CT measurement variability discussed by the authors. Oxygen was not matched, so effects cannot be attributed to hydrogen alone. Most secondary markers were within normal ranges; multiple comparisons and exploratory smoking subgroups lacked formal interaction testing. Registration dates and baseline Mayo scores conflict within the report. These findings do not establish cancer prevention or treatment.
What kind of evidence is this?
Human
Single-centre randomized parallel clinical trial; random-number table and sealed envelopes; assessors, laboratory staff and statisticians blinded, patients/operators not blinded.
Respiratory health
Inhaled H₂
Information not yet classified
Some editorial classification fields are still pending. The source-reported outcomes and result are shown below; Hydrogenology does not infer a positive or negative signal from prose automatically.
Methods
Adults aged 60–75 with a solitary pulmonary nodule no larger than 10 mm.
67 screened, 8 excluded before randomization; 59 randomized and analyzed (30 hydrogen–oxygen, 29 air). All randomized participants were reported to complete follow-up.
4 hours/day in two 2-hour sessions for 14 days; outcomes assessed at 3 months.
4 hours/day, split into two 2-hour sessions, for 14 days; outcome follow-up at 3 months.
Hydrogen and oxygen source-gas mixture; source composition is distinct from inspired concentration.
Approximately 66.6% H₂ and 33.3% O₂, total 3,000 mL/min. Approximately 2,000 mL/min H₂ is calculated from the reported mixture, not a measured inhaled dose. Actual inspired H₂ concentration was not measured separately from generated gas.
Reported total source flow 3,000 mL/min. Approximately 2,000 mL/min H₂ is calculated from the source mixture, not measured inhaled dose.
33.3% source O₂ versus approximately 21% in the air control; not oxygen matched.
Air through the same flow/device schedule. Not oxygen matched: air has approximately 21% O₂ versus source mixture 33.3% O₂. Both groups received usual health/smoking advice.
Outcomes and reported result
Change in CT-measured nodule diameter at three months.
Mean nodule diameter: hydrogen: 3.97 to 3.33 mm; reduction 0.64 mm, 95% CI 0.20 to 1.08; within-group p = 0.006; comparator: 4.29 to 4.19 mm; reduction 0.10 mm, 95% CI −0.32 to 0.52; within-group p = 0.641; Post-treatment diameter: 3.33 versus 4.19 mm; reported p < 0.001. The confidence intervals above describe changes within each group, not the difference between groups. IL-6: hydrogen: 5.04 to 3.68 pg/mL; comparator: 5.21 to 5.05 pg/mL; between group: Post-treatment p < 0.001. Neutrophils: hydrogen: 3.77 to 2.63 × 10^9/L; comparator: 4.10 to 3.85 × 10^9/L; between group: Post-treatment p = 0.001. CRP and Mayo malignancy risk score: between group: Post-treatment p = 0.239 and p = 0.946 respectively; not significant.
The available main full text was reviewed for methods, results, limitations and declarations. Remaining source-specific uncertainties are stated in this record.
No intervention-related or severe adverse events reported. Discussion acknowledges limited systematic adverse-event reporting; this is not sufficient to establish safety.
A reported association, difference or mechanism is not automatically a clinical benefit.
Limitations and applicability
Small single-centre trial with three-month follow-up and no clinical cancer endpoint. The 0.64 mm within-group diameter change is close to approximately 0.6 mm CT measurement variability discussed by the authors. Oxygen was not matched, so effects cannot be attributed to hydrogen alone. Most secondary markers were within normal ranges; multiple comparisons and exploratory smoking subgroups lacked formal interaction testing. Registration dates and baseline Mayo scores conflict within the report. These findings do not establish cancer prevention or treatment.
Adults aged 60–75 with a solitary pulmonary nodule no larger than 10 mm. Findings apply only to the studied design and exposure; no treatment or device recommendation.
Dongying City Major Science and Technology Innovation Special Projects, 2024ZDJH91.
No competing interests declared. Authors state generator manufacturer had no role in design, collection, analysis, drafting or publication decision.
No single-study GRADE certainty rating is assigned. Read how records and evidence assessments are prepared.
Sources and record status
PMID: 42453934 · DOI: 10.2147/dddt.s605134
Complete article in PubMed Central, including tables.
AI-assisted editorial review of the available main full text, 29 October 2026. The source version and access limitations are stated in this record. No independent clinical or statistical assessment has been performed.
General Information; Therapeutic Regimens; Detection Imaging; Statistical Analysis Results; Table 1; Figures 2–3 and captions Discussion, including measurement variability and safety reporting limitations Funding and Disclosure
AI-assisted editorial review of the available main full text, 29 October 2026. Complete article in PubMed Central, including tables.
The article reports registration ChiCTR2300076152, with conflicting dates: 26 September 2023 in the abstract and 26 September 2025 in Methods. Independent registry timing has not been confirmed.
29 October 2026
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