Choker:
I thought the results may be different for different patients, because so many people claim to be affected by the weather, esp. barometric pressure. A study with a representative sample might reveal things we may only suspect,
or negate the claims made by those who feel symptoms that may not be observable in all subjects.
Machine pressure would not be a factor, unless a machine without automatic altitude adjustment were used; since cms/H2O is just a differential compared to ambient air pressure. (frog takes a deep breath)
Stormy Weather Worsens Sleep Apnea
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chunkyfrog
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Re: Stormy Weather Worsens Sleep Apnea
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Re: Stormy Weather Worsens Sleep Apnea
Here's the published article citation. Note that the article itself is free, if you want to read it.
J Clin Sleep Med. 2010 Apr 15;6(2):152-6.
Do weather-related ambient atmospheric-pressure changes influence sleep disordered breathing?
Doherty MJ, Youn CE, Haltiner AM, Watson NF.
Source
Swedish Epilepsy Center, Seattle, WA 98122, USA. Michael.doherty@swedish.org
Abstract
OBJECTIVE:
High-altitude studies of sleep disordered breathing (SDB) show increases in apnea hypopnea indices with elevation gains. Hypoxic changes, rather than reductions in atmospheric pressure (AP), are thought to be the driving factor. Ambient pressure-related changes in SDB have not been extensively studied at low altitude. We performed a cross-sectional study of weather-related AP effects on measures of SDB at the University of WashingtonMedicine Sleep Institute, a Seattle, Washington-based polysomnography lab located 200 feet above sea level.
METHOD:
Obstructive, central, and apnea-hypopnea indices from 537 patients were retrospectively correlated to mean 8-hour date-matched overnight AP data. Linear regression analysis and interquartile comparison of AP-related respiratory indices were performed and adjusted for age, sex, and body mass index.
RESULTS:
The obstructive apnea index increased with lower weather-related APs (p = 0.01 for linear trend), interquartile analysis showed significant worsening with lowered mean, minimum, and maximum nightly APs. Similar changes were not seen with central or apnea-hypopnea indices.
CONCLUSIONS:
The obstructive apnea index is altered by changes in weather-related AP during diagnostic polysomnography performed at 200 feet above sea level. Small changes in ambient atmospheric pressure due to weather systems may be important in the pathophysiology and diagnosis of obstructive sleep apnea.
PMID: 20411692 [PubMed - indexed for MEDLINE] PMCID: PMC2854702 Free PMC Article
J Clin Sleep Med. 2010 Apr 15;6(2):152-6.
Do weather-related ambient atmospheric-pressure changes influence sleep disordered breathing?
Doherty MJ, Youn CE, Haltiner AM, Watson NF.
Source
Swedish Epilepsy Center, Seattle, WA 98122, USA. Michael.doherty@swedish.org
Abstract
OBJECTIVE:
High-altitude studies of sleep disordered breathing (SDB) show increases in apnea hypopnea indices with elevation gains. Hypoxic changes, rather than reductions in atmospheric pressure (AP), are thought to be the driving factor. Ambient pressure-related changes in SDB have not been extensively studied at low altitude. We performed a cross-sectional study of weather-related AP effects on measures of SDB at the University of WashingtonMedicine Sleep Institute, a Seattle, Washington-based polysomnography lab located 200 feet above sea level.
METHOD:
Obstructive, central, and apnea-hypopnea indices from 537 patients were retrospectively correlated to mean 8-hour date-matched overnight AP data. Linear regression analysis and interquartile comparison of AP-related respiratory indices were performed and adjusted for age, sex, and body mass index.
RESULTS:
The obstructive apnea index increased with lower weather-related APs (p = 0.01 for linear trend), interquartile analysis showed significant worsening with lowered mean, minimum, and maximum nightly APs. Similar changes were not seen with central or apnea-hypopnea indices.
CONCLUSIONS:
The obstructive apnea index is altered by changes in weather-related AP during diagnostic polysomnography performed at 200 feet above sea level. Small changes in ambient atmospheric pressure due to weather systems may be important in the pathophysiology and diagnosis of obstructive sleep apnea.
PMID: 20411692 [PubMed - indexed for MEDLINE] PMCID: PMC2854702 Free PMC Article
roster wrote:Stormy Weather Worsens Sleep Apnea
By Kristina Fiore, Staff Writer, MedPage Today
Published: May 01, 2009
Reviewed by Zalman S. Agus, MD; Emeritus Professor
University of Pennsylvania School of Medicine.
SEATTLE, May 1 -- Patients with sleep-disordered breathing may find their condition worsens when a storm blows through town, researchers said here.
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Action Points
Explain that measurements of obstructive apnea significantly worsened as atmospheric pressure dropped due to weather-related changes.
Note that previous research had linked sleep-disordered breathing problems to altitude and hypoxia, but weather-related changes in atmospheric pressure and their effects on sleep apnea have not been evaluated.
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Note that this study was published as an abstract and presented orally at a conference. These data and conclusions should be considered to be preliminary until published in a peer-reviewed journal.
Obstructive apnea worsened as atmospheric pressure dropped due to weather-related changes, Michael J. Doherty, M.D., of Swedish Hospital here, and colleagues reported at the American Academy of Neurology meeting.
"We saw strong results between weather-related atmospheric pressure changes and sleep-disordered breathing," Dr. Doherty said.
Previous research has found that altitude is linked to worsening apnea, possibly a result of hypoxia or changes in air viscosity.
Altitude changes, however, correspond to central apnea, more so than obstructive apnea, which was most affected in the present study.
"We're not sure why that is," Dr. Doherty said.
To investigate the impact of low-altitude, weather-related changes in atmospheric pressure on respiration during sleep -- which has been largely unstudied -- the researchers retrospectively correlated 30 months of Seattle weather data with polysomnography data from sleep studies of 537 patients at the University of Washington Sleep Disorders Center.
The lab is located 200 feet above sea level.
The polysomnography data contained indices of obstructive, central, and apnea-hypopnea events.
In a multivariate analysis, the obstructive apnea index increased as atmospheric pressure lowered due to weather-related changes (P=0.01).
There was also significant worsening with lowered mean, minimum, and maximum nightly atmospheric pressures.
However, there were no significant changes for central apnea or apnea-hypopnea indices.
Dr. Doherty said the pressure change itself may drive the correlation, but the researchers are still not sure of the exact mechanism by which it operates.
He said there are similar results when patients suffering from sleep-disordered breathing at high altitudes are brought down to lower altitudes. They often experience more obstructive apnea events and fewer central apnea events than before.
Though the mechanism remains a mystery, Dr. Doherty said the obstructive apnea index is clearly altered by changes in weather-related atmospheric pressure.
The researchers reported no conflicts of interest.
Primary source: American Academy of Neurology
Source reference:
Doherty, MJ "Preliminary observations of weather-related ambient atmospheric pressure changes on sleep-disordered breathing" AAN 2009; Abstract IN5-1.007.
http://www.medpagetoday.com/MeetingCoverage/AAN/14020