[Five-year monitoring of annual pulmonary function decline in individuals exposed to chronic intermittent hypoxia].
OBJECTIVE
To study annual decline of pulmonary function in individuals exposed to chronic intermittent hypoxia (CIH) working in conditions of high altitude for 5 years.


METHODS
A total of 9553 spirograms were obtained during 5 annual examinations of 795 open-cast miners (age 38.6 +/- 8.5 years, 6.4 +/- 5.0 years of service) working at the altitude of 3800-4500 m above the sea level. The miners were examined using spirometry with bronchodilation test.


RESULTS
An annual decline of vital lung capacity (VC) was 33.5 ml/year of forced VC - 33.8 ml/year, forced expiratory volume (FEV1)--64.4 ml/year. In the group of non-smokers the decline was less than in smokers--FEV1 59.5 ml/year vs 72.0 ml/year. No-smoking rules in the open-cast mine inhibited a respiratory function decline.


CONCLUSIONS
Individuals exposed to CIH show an accelerated decline of spirometric indices. No-smoking rules at open-cast high altitude mines result in inhibition of annual decline of respiratory function in CIH-exposed individuals including non-smokers. Smoking ban in such conditions not only inhibits decline of the respiratory function but improves this function.
D000328:Adult; D000531:Altitude; D002908:Chronic Disease; D005260:Female; D006801:Humans; D000860:Hypoxia / Q000150:complications*; D008168:Lung / Q000502:physiology / Q000503:physiopathology*; D008297:Male; D008906:Mining; D009784:Occupational Diseases / Q000209:etiology; D011446:Prospective Studies; D012907:Smoking / Q000009:adverse effects; D013147:Spirometry