Preliminary Effects of Hydrogen-Oxygen Inhalation on Nodule Size, IL-6, and Neutrophils in Patients with Small Pulmonary Nodules.

OBJECTIVE

To evaluate the effects of hydrogen-oxygen inhalation on nodule diameter and peripheral blood inflammatory factors in patients with small pulmonary nodules (SPNs), and to further analyze its efficacy in the smoking subgroup. The primary endpoint was the change in pulmonary nodule diameter before and after intervention; secondary endpoints included alterations in serum IL-6, CRP, peripheral blood neutrophil count, and Mayo malignant transformation risk score.

METHODS

A total of 59 patients with SPNs confirmed by chest CT were enrolled and randomly divided into the observation group (hydrogen-oxygen inhalation, n=30) and control group (air inhalation, n=29). The intervention lasted 14 consecutive days, and all indicators were re-examined at 3-month follow-up. This study was registered in the Chinese Clinical Trial Registry (ChiCTR) with the registration number ChiCTR2300076152 (registration date: September 26, 2023).

RESULTS

Baseline demographic and clinical characteristics were well balanced between the two groups (all P>0.05). After intervention, the observation group had a significant reduction in nodule diameter by 0.64 mm (95% CI: 0.20-1.08, P<0.01). Serum IL-6 decreased by 1.36 pg/mL (95% CI: 0.70-2.02, P<0.01), and peripheral blood neutrophil count decreased by 1.14×109/L (95% CI: 0.51-1.77, P<0.01). No significant pre- and post-intervention differences were observed in CRP level and Mayo malignant transformation risk score in either group (all P>0.05). In the smoking subgroup, IL-6 level and neutrophil count also decreased significantly after hydrogen-oxygen inhalation (both P<0.01), while CRP remained relatively stable.

CONCLUSION

Within the limitations of this single-center, small-sample study with a 3-month follow-up, hydrogen-oxygen inhalation can reduce SPN diameter and downregulate peripheral blood IL-6 and neutrophil levels, exerting a targeted anti-inflammatory effect especially in smoking patients. It may serve as a safe non-invasive adjuvant intervention for SPNs, while further multicenter large-sample studies are needed to validate its general applicability.