Hydrogen Therapy Protects Blood Vessels in Sleep Apnea Patients

Authors
Journal
Journal of Thoracic Disease
Year
DOI
10.21037/jtd-2025-1345
Study Type
Rat
Outcome
Positive
Peer Reviewed
Yes
Country
China
Health Condition
Obstructive Sleep Apnea-Hypopnea Syndrome
Body System
Cardiovascular

TL;DR

Hydrogen inhalation protected blood vessels from sleep apnea–related damage by reducing oxidative stress and restoring nitric oxide signaling.

Key Finding

Molecular hydrogen treatment protected blood vessel linings in rats with simulated sleep apnea by reducing oxidative stress and restoring nitric oxide production, which improved blood vessel function.

Summary

Obstructive sleep apnea causes repeated drops in blood oxygen that damage blood vessel linings through oxidative stress (cellular damage from unstable molecules). This study tested whether molecular hydrogen could protect these blood vessels in rats with sleep apnea-like conditions. Researchers found that hydrogen treatment reduced oxidative stress, restored the production of nitric oxide (a molecule that helps blood vessels relax), and reduced inflammation and cell death in blood vessel tissue.

Practical Takeaway

This rat study suggests hydrogen may help protect blood vessels damaged by sleep apnea, but human studies are needed to determine if these benefits apply to people. The findings are preliminary and should not be considered a treatment recommendation for sleep apnea, which requires medical management.

Abstract

Background: Obstructive sleep apnea-hypopnea syndrome (OSAHS) is a highly prevalent disorder characterized by chronic intermittent hypoxia (IH), which induces severe vascular endothelial dysfunction via oxidative stress and disruption of nitric oxide (NO) homeostasis, thereby elevating cardiovascular risk. Molecular hydrogen (H2) has emerged as a selective antioxidant with therapeutic potential, but its protective mechanisms against OSAHS-induced endothelial injury remain largely unexplored. This study aimed to investigate whether H2 preserves endothelial function in the context of OSAHS by restoring NO bioavailability and to elucidate the underlying molecular pathways. Methods: We employed a translational approach using both in vitro and in vivo models of IH. Human umbilical vein endothelial cells were subjected to IH cycles (1% O2 for 5 min/21% O2 for 10 min) for 24 hours with or without H2-rich medium (0.6 mM). In parallel, a rat model of OSAHS was established by exposing animals to IH (8% O2 for 5 min/21% O2 for 5 min, 8 hours/day) for 4 weeks, with a treatment group receiving daily 2% H2 inhalation for 1 hour. We comprehensively assessed vascular pathology, oxidative stress markers [reactive oxygen species (ROS)/malondialdehyde (MDA)], key elements of the NO pathway [endothelial nitric oxide synthase (eNOS) phosphorylation, tetrahydrobiopterin (BH4) and its oxidized form BH2], inflammation [tumor necrosis factor-α (TNF-α), intercellular cell adhesion molecule-1 (ICAM-1)], and apoptosis. Results: Our findings demonstrate that H2 treatment significantly mitigated IH-induced oxidative stress, reducing ROS and MDA levels both in cells and aortic tissues. Crucially, H2 restored NO bioavailability by enhancing eNOS phosphorylation at Ser1177 and preserving the critical BH4/BH2 ratio, thereby preventing eNOS uncoupling and superoxide overproduction. This was functionally confirmed by a marked improvement in endothelium-dependent vasodilation in H2-treated OSAHS rats. Furthermore, H2 administration attenuated vascular remodeling, reducing medial thickening and collagen deposition, and suppressed the inflammatory response by downregulating TNF-α and ICAM-1 expression. Finally, H2 significantly reduced endothelial apoptosis in aortic tissues. Conclusions: H2 effectively alleviates OSAHS-related endothelial dysfunction by modulating redox homeostasis, recoupling eNOS to enhance NO production, and concurrently inhibiting inflammatory activation and apoptosis. These multifaceted protective effects highlight the significant therapeutic potential of H2 as a novel adjunctive strategy for mitigating cardiovascular complications in in patients with OSAHS.