H₂ Papers

日本語 ・View as Markdown

The efficacy of hydrogen/oxygen therapy favored the recovery of omicron SARS-CoV-2 variant infection: results of a multicenter, randomized, controlled trial.

オミクロン株SARS-CoV-2感染回復における水素/酸素吸入の有効性：多施設無作為化対照試験

human randomized controlled trial inhalation positive

Abstract

This multicenter randomized controlled trial enrolled 64 patients with Omicron SARS-CoV-2 infection, randomly allocated to hydrogen/oxygen mixed gas inhalation (n=32) or oxygen-only inhalation (n=32). The hydrogen/oxygen group demonstrated a shorter viral shedding duration compared with the control group. Cumulative negative conversion rates showed a progressive increase from day 3 onward in the hydrogen/oxygen group. IL-6 concentrations declined by 22.8% from baseline, and lymphocyte counts rose to 61.1% of baseline values by day 3 in the hydrogen/oxygen group. A greater proportion of patients in the hydrogen/oxygen group exhibited resolution of pulmonary lesions on imaging. These findings indicate that molecular hydrogen inhalation may support immune recovery and reduce inflammatory markers in COVID-19 patients.

Mechanism

Inhalation of hydrogen/oxygen mixed gas was associated with reduced IL-6 levels and restored lymphocyte counts, suggesting suppression of inflammatory cytokine signaling and enhancement of immune cell recovery, which may have contributed to faster viral clearance and pulmonary lesion resolution.

Bibliographic

Authors
Shi MM, Chen Y, Wang X, Zhang YJ, Cheng T, Chen H, et al.
Journal
J Clin Biochem Nutr
Year
2023
PMID
37970554
DOI
10.3164/jcbn.23-32
PMC
PMC10636573

Tags

Disease:COVID-19 (25) Delivery:inhalation delivery (196) Mechanism:immune modulation (180) anti-inflammatory (743) oxidative stress (899) reactive oxygen species (774)

Delivery context

In air, molecular hydrogen is reported to be combustible across approximately **4% (LFL, lower flammability limit) to 75% (UFL, upper flammability limit)**. Among high-concentration hydrogen inhalers, 66% output sits inside this range, and even pure-hydrogen (100%) output forms a 4–75% concentration-gradient layer at the device–air boundary (the UFL 75% paradox). Engineering principle would therefore call for operation below LFL (the classical 4%); that figure, however, was measured under closed, pre-mixed, static conditions. For the open, dynamic inhalation environment, the empirical value reported in the literature is **10%**, which is the figure referenced in practice as the operating ceiling. The 66% / 100% output devices are recorded in the Japanese Consumer Affairs Agency accident-information database, and from these considerations are not recommended.

→ Evidence by delivery route

Safety notes

In air, molecular hydrogen is reported to be combustible across approximately **4% (LFL, lower flammability limit) to 75% (UFL, upper flammability limit)**. Among high-concentration hydrogen inhalers, 66% output sits inside this range, and even pure-hydrogen (100%) output forms a 4–75% concentration-gradient layer at the device–air boundary (the UFL 75% paradox). Engineering principle would therefore call for operation below LFL (the classical 4%); that figure, however, was measured under closed, pre-mixed, static conditions. For the open, dynamic inhalation environment, the empirical value reported in the literature is **10%**, which is the figure referenced in practice as the operating ceiling. The 66% / 100% output devices are recorded in the Japanese Consumer Affairs Agency accident-information database, and from these considerations are not recommended.

See also:

Other papers on the same disease / condition