CHRONIC MOUNTAIN-SICKNESS AND CHRONIC LOWER RESPIRATORY-TRACT DISORDERS

To determine whether chronic lower respiratory tract disorders contrib uted to the development of chronic mountain sickness (CMS), we compare d hemoglobin (Hb), oxygen saturation (SaO(2)), beak expiratory now rat e (PEFR), and CMS scores (CMSsco) in 97 normal men at high altitude wi th those of men at high altitude with acute (ARD; n = 12), chronic upp er (CURD; n = 33), and chronic lower (CLRD; n = 34) respiratory diseas es. The clinical diagnosis of the different types of respiratory disor ders was based on the results of a questionnaire and physical examinat ion performed during an epidemiologic study. The CLRD group had higher CMSsco and Hb concentrations, and lower SaO(2) and PEFR values when c ompared with the other groups. The frequency of low PEFR and SaO(2) an d high Hb and CMSsco was substantially higher in men with CURD when co mpared with normal subjects. The results support the hypothesis that t here is an association between signs and symptoms of CMS, as measured by the CMSsco, and CLRD. The chronic hypoxemia, product of chronic lun g diseases, would cause excessive erythrocytosis and increase the sign s and symptoms of CMS. Studies of Hb, PEFR, pulse oximetry, and CMSsco are recommended for early detection of high-altitude natives at risk of developing CMS.