Low oxygen may help to ease symptoms in Parkinson’s: Report
But more research is needed to confirm strategy's safety, effectiveness
Exposure to low oxygen may help to ease the symptoms of Parkinson’s disease — but a lot more research is needed to conclusively determine the safety and effectiveness of this strategy for use among people with the neurodegenerative disorder, according to a new report.
“From a clinical perspective, hypoxia [low oxygen] exposure appears to hold potential as an effective complementary strategy for treating” Parkinson’s, the scientists wrote.
Oxygen is a gas in the air that’s essential for the body’s ability to generate energy. While prolonged exposure to very low oxygen levels can have serious health consequences, there’s emerging data suggesting that brief periods of exposure to mildly decreased oxygen levels might stabilize hypoxia-inducible factor-1 (HIF-1alpha), a protein that controls cellular responses to oxygen availability.
Such a strategy potentially could be protective in Parkinson’s, according to a new paper, titled “Acute and cumulative effects of hypoxia exposure in people with Parkinson’s disease: A scoping review and evidence map” and published in Parkinsonism & Related Disorders.
Low oxygen exposure in Parkinson’s may have protective effect
“The focus of pharmacological treatment [in Parkinson’s] is on symptoms, promoting no neuroprotection. Thus, complementary strategies should be investigated,” the team wrote.
To that end, these scientists, in Brazil, conducted a review of the available scientific literature, looking for studies that assessed the effects of a low oxygen intervention in people with Parkinson’s.
The review included eight studies covering a total of 123 patients. Three of the studies were done in Sweden, two in Ukraine, two in Australia, and one in Japan. Some studies assessed an intervention in which low oxygen was given at normal air pressure, while others used hypobaric (low pressure) and low oxygen, such as what occurs at high altitudes.
The reviewed studies generally did not report any safety issues related to the low oxygen protocols, though the researchers noted that in some cases, the detailed protocols used were unclear. They also highlighted that all the studies assessed just a brief period of low oxygen — typically one or two weeks — so no conclusions can be made about the safety of long-term or repeated interventions.
The current literature is incipient [in early stages], limiting the use of hypoxia exposure in practical settings.
When people are exposed to low oxygen, they normally start breathing more as the body tries to get more oxygen, which is known as the hypoxia ventilatory response, or HVR for short. Data from the studies suggested that people with Parkinson’s tended to have a less pronounced HVR compared with people without the disease. Parkinson’s patients also tended to report less subjective feelings of breathlessness in low oxygen environments, the data showed.
This difference in HVR is likely explained by reduced dopamine signaling, the researchers said. Parkinson’s is caused by the death and dysfunction of nerve cells responsible for making dopamine, an important chemical messenger that nerve cells use to communicate with each other and the rest of the body.
Across the studies, data generally suggested a beneficial effect of low oxygen. For example, in the three studies from Sweden in which patients were exposed to low oxygen at low pressures, these individuals experienced improvements in motor function as measured by the Posturo-Locomotor-Manual test. These improvements were maintained at three months after the intervention, but by six months scores had decreased again. Measures of life quality also showed short-term improvements.
Other studies indicated that two weeks of exposure to low oxygen at normal pressures led to improvements in HVR, particularly among patients who were taking medications for Parkinson’s. Those findings are suggestive of increased dopamine signaling.
While these findings are promising, the researchers stressed that only a handful of studies in this area have been done, and none of the studies included a control group so it’s impossible to rule out the placebo effect as an explanation for improvements.
The scientists emphasized a need for additional research on low oxygen therapies for Parkinson’s, highlighting a particular need for controlled clinical trials that assess in detail the effect of these interventions on various Parkinson’s symptoms and also test how these interventions interact with other Parkinson’s treatments.
“The current literature is incipient [in early stages], limiting the use of hypoxia exposure in practical settings,” the researchers concluded.