Summary:
A clinical trial from São Paulo State University (UNESP) in Brazil shows that a single controlled session of intermittent hypoxia — brief, alternating exposures to low-oxygen air — is safe for people with Parkinson’s disease, does not disturb sleep, and produces beneficial changes in metabolic and inflammatory blood markers. Published in Parkinsonism & Related Disorders, the randomized, double-blind, crossover study found that a 39-minute protocol reduced stress and pro-inflammatory signals, increased the neuroprotective hormone adiponectin, and prevented a decline in brain-derived neurotrophic factor (BDNF), suggesting intermittent hypoxia as a promising complementary therapy to explore further.
Key Facts:
- Controlled, safe exposure: The protocol alternated four 6-minute cycles breathing 10% oxygen (equivalent to roughly 5,800 m altitude) with three 5-minute intervals of room air; no adverse events, insomnia, or sleep disruption were observed in either Parkinson’s patients or matched healthy controls.
- Anti-inflammatory and metabolic effects: After one session, cortisol and leptin fell transiently while adiponectin rose and stayed elevated for up to 24 hours in people with Parkinson’s.
- Neurotrophic support: Intermittent hypoxia prevented the expected drop in circulating BDNF seen during passive rest, without raising the pro-inflammatory cytokine interleukin-6 (IL-6) or disturbing iron balance.
Source: São Paulo State University (UNESP) / FAPESP
Background on Parkinson’s disease: Parkinson’s disease affects millions worldwide and is characterized clinically by progressive loss of dopaminergic neurons in the substantia nigra, producing classic motor symptoms such as resting tremor, slowness of movement (bradykinesia), postural instability, and rigidity. Beyond these motor deficits, many people with Parkinson’s experience non-motor burdens including disrupted metabolism, chronic neuroinflammation, and persistent sleep problems that dopaminergic medications do not reliably resolve.
To date, structured exercise remains the primary non-pharmacological approach with evidence for improving metabolic and neurotrophic health in Parkinson’s. The UNESP team, with support from the São Paulo Research Foundation (FAPESP), investigated intermittent hypoxia as a supplementary, non-drug strategy that may activate protective cellular pathways through a hormetic mechanism.
Harnessing Hormesis: Controlled Stress to Trigger Repair
High-altitude thin air can be harmful when exposure is prolonged, but brief, repeated dips in oxygen level can induce hormesis — a process where mild, non-damaging stress activates adaptive, protective responses in cells. The UNESP researchers designed a tightly controlled, short-duration intermittent hypoxia protocol intended to recruit those protective mechanisms without overloading vulnerable tissues.
Fabio Barbieri, PhD, director of the Human Movement Research Laboratory (MOVI-LAB) and coordinator of the “Ativa Parkinson” program at UNESP Bauru, emphasized that the initial findings demonstrate safety and acute benefit, supporting the feasibility of larger and longer trials to test repeated-session effects.
The trial enrolled 30 adults: 15 diagnosed with Parkinson’s disease and 15 neurologically healthy, age-matched controls. Each participant completed two experimental visits in randomized order. One visit used the intermittent hypoxia protocol lasting 39 minutes; the other was a sham/control session breathing normal room air throughout.
Design and Physiological Monitoring
During the active session participants wore breathing masks that delivered four 6-minute hypoxic blocks (inspired oxygen fraction FiO2 = 0.10) alternating with three 5-minute normoxic recovery periods (FiO2 = 0.21). The protocol produced a measurable reduction in peripheral oxygen saturation (SpO2) and an increased hypoxic dose compared with the normoxic control, confirming the intended physiological stimulus.
Biomarker and Sleep Outcomes
Blood samples and actigraphy-based sleep measurements were taken at baseline, immediately after each session, and 24 hours later. Key results in people with Parkinson’s included:
- Stress and inflammatory markers: Cortisol and leptin decreased acutely after intermittent hypoxia.
- Adiponectin increase: Adiponectin rose significantly and remained elevated at 24 hours; this protein has anti-inflammatory and vascular-protective roles and is often reduced in Parkinson’s.
- BDNF preservation: While passive rest in normal air produced the expected decline in circulating BDNF, the hypoxia protocol prevented that reduction, suggesting maintenance of a key neurotrophic signal.
Importantly, the intervention did not raise IL-6 or perturb iron homeostasis, alleviating concerns that hypoxia might provoke systemic inflammation. Objective sleep monitoring showed no increase in awakenings or sleep-onset latency after the hypoxia session; total sleep time decreased modestly 24 hours after the intervention compared with immediate post-session readings, but there was no evidence of nocturnal harm or central sleep apnea provoked by the protocol.
Mechanisms and Next Steps
Co-author Carlos Augusto Kalva-Filho, PhD, points to hypoxia-inducible factor 1-alpha (HIF-1α) as a likely mediator. HIF-1α is an intracellular oxygen sensor that coordinates mitochondrial bioenergetics and antioxidant defenses when activated by brief oxygen drops. The investigators note that precisely timed laboratory cycles of hypoxia can trigger repair pathways that continuous high-altitude exposure would not safely elicit.
While one session demonstrated acute biochemical benefits and sleep safety, the authors stress that intermittent hypoxia is investigational and not a substitute for established dopaminergic therapies. Ongoing plans include multi-week studies to evaluate whether repeated sessions produce cumulative improvements in motor function, cognition, sleep, and sustained physiological adaptation.
Editorial Notes:
- This article was edited by a Neuroscience News editor.
- The journal paper was reviewed in full by the editorial team.
- Additional, clarifying context was added by staff to aid reader understanding.
About this Parkinson’s disease Research:
- Media Contact: Heloisa Reinert
- Source: FAPESP
- Image Credit: Image credited to Neuroscience News
- Original Research (Open Access): Parkinsonism & Related Disorders (Oct 1, 2026). Title: “The acute effects of a single session of intermittent hypoxia on blood biomarker concentrations and sleep parameters in people with Parkinson’s disease: A randomized, double-blind, crossover trial.” Authors: Murilo Henrique Faria, Carlos Augusto Kalva-Filho, Vinicius Oliveira Queiroz, Tjeerd W. Boonstra, Marcela de Oliveira, Jônatas Augusto Cursiol, Christian Schlenstedt, Fabio Santos Lira, Barbara Moura Antunes, and Fabio Augusto Barbieri.
- DOI: 10.1016/j.parkreldis.2026.108922
Abstract
The acute effects of a single session of intermittent hypoxia on blood biomarker concentrations and sleep parameters in people with Parkinson’s disease: A randomized, double-blind, crossover trial
Background
People with Parkinson’s disease often show altered sleep and blood biomarkers. Intermittent normobaric hypoxia (IH) may offer neuroprotective effects, but its immediate impacts are not well defined. This study investigated the acute and 24-hour retention effects of one IH session on sleep metrics and blood biomarkers in people with Parkinson’s disease.
Methods
Fifteen people with Parkinson’s disease and 15 sex-matched neurologically healthy individuals took part in a randomized, double-blind, crossover protocol. Each participant experienced two 39-minute conditions: (i) IH, consisting of four 6-minute hypoxic cycles (FiO2 = 0.10) separated by three 5-minute normoxic periods; and (ii) a normoxia control with constant room-air oxygen (FiO2 = 0.21). Actigraphy assessed sleep, and blood biomarkers (BDNF, cortisol, IL-6, iron, leptin, adiponectin) were measured at baseline, immediately after each session, and 24 hours later.
Results
The IH protocol reduced SpO2 by 5–20% and delivered a nearly fivefold greater hypoxic dose than normoxia, confirming effective simulation. No adverse changes in sleep parameters were observed after IH compared with baseline in either group. In people with Parkinson’s, IH acutely reduced cortisol and leptin and raised adiponectin levels; BDNF, IL-6, and iron showed no significant changes immediately post-session, though IH prevented the BDNF decline seen during the control condition.
Conclusion
A single session of intermittent hypoxia is a safe, well-tolerated method to induce controlled hypoxia and modulate key blood biomarkers in people with Parkinson’s disease without compromising sleep. These results support further research into repeated IH sessions to determine whether cumulative physiological and clinical benefits can be achieved over time.
