Document Detail


High altitude exposure reduces bronchial responsiveness to hypo-osmolar aerosol in lowland asthmatics.
MedLine Citation:
PMID:  8620949     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
It is well-known that many patients with asthma undergo clinical improvement during a stay at high altitude. At high altitude, the atmospheric and climatic conditions (such as hypoxia, cold and dry air inhalation) could modify the bronchial responsiveness in asthmatics. Our study was designed to assess the difference in bronchial responsiveness to hypotonic aerosol between sea level and high altitudes in nonresident asthmatic subjects. The results were obtained during two mountaineering expeditions above 4,000 m i.e. at 4,559 m on Mt Rosa, Italy; and at 5,050 m near the Mt Everest base camp in Nepal. Eleven mild asthmatics performed standard bronchial challenges with ultrasonically nebulized distilled water (5 min inhalation, delivery 2 mL-min-1) at sea level and after staying at least 72 h at the above mentioned altitudes. The decrease in forced expiratory volume in one second (FEV1) from baseline was used as index of bronchial response. There was no significant difference in pre-challenge FEV1 between sea level and high altitude in either study. However, the bronchoconstriction response to ultrasonically nebulized distilled water was significantly reduced at high altitude in both studies. At sea level the mean FEV1 decrease was 22.2% (range 15-35%), whereas as the maximal altitude it was 6.7% (range 2-11%). Our results indicate that there is a reduction in bronchial responsiveness to hypoosmolar aerosol at high altitude. This suggests that atmospheric and climatic conditions, or physiological adaptations, via mediators such as atrial natriuretic peptide, are beneficial to patients with asthma at high altitude.
Authors:
L Allegra; A Cogo; D Legnani; P L Diano; V Fasano; G G Negretto
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Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  The European respiratory journal     Volume:  8     ISSN:  0903-1936     ISO Abbreviation:  Eur. Respir. J.     Publication Date:  1995 Nov 
Date Detail:
Created Date:  1996-06-14     Completed Date:  1996-06-14     Revised Date:  2013-05-23    
Medline Journal Info:
Nlm Unique ID:  8803460     Medline TA:  Eur Respir J     Country:  DENMARK    
Other Details:
Languages:  eng     Pagination:  1842-6     Citation Subset:  IM    
Affiliation:
Institute of Respiratory Diseases, University of Milan, Italy.
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MeSH Terms
Descriptor/Qualifier:
Adult
Aerosols
Altitude*
Analysis of Variance
Asthma / physiopathology*
Bronchial Hyperreactivity / physiopathology*
Female
Forced Expiratory Volume / drug effects
Humans
Hypotonic Solutions / administration & dosage,  pharmacology
Male
Middle Aged
Water / administration & dosage,  pharmacology*
Chemical
Reg. No./Substance:
0/Aerosols; 0/Hypotonic Solutions; 7732-18-5/Water

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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