title: Effect of low altitude at the Dead Sea on exercise capacity and cardiopulmonary response to exercise in cystic fibrosis patients with moderate to severe lung disease.
abstract: Oxygen supplementation may improve exercise tolerance and the physiological response to exercise in cystic fibrosis (CF) patients. Elevated barometric pressure at low altitude is a simple means of increasing the quantity of inspired oxygen. Our objectives were to examine the effect of natural oxygen enrichment (at the Dead Sea, 396 m below sea level) on exercise capacity, and the physiological responses to maximal and submaximal exercise in CF patients. Patients were tested twice: at sea level (barometric pressure, 754 +/- 6 mmHg, mean +/- SD), and at the Dead Sea (barometric pressure, 791 +/- 3 mmHg), in a randomized crossover design. We studied 14 CF patients (6 females, 8 males), aged 15-45 years, with moderate to severe lung disease (mean forced expired volume in 1 sec = 50.0 +/- 11.2% predicted). Tests at each site included resting spirometry, anthropometry, a graded submaximal exercise test, a maximal exercise test on a treadmill, and a 6-min walk test. Tests were performed in identical order at both sites. Tests at the Dead Sea were performed 72 hr after arrival. No differences between sites were observed in lung function at rest. Peak oxygen consumption was significantly improved at the Dead Sea compared with sea level (1.68 +/- 0.73 vs. 1.57 +/- 0.74 l/min, respectively, P = 0.05), along with an improvement in the ventilatory equivalent for oxygen (41.2 +/- 6.3 vs. 46.1 +/- 7.1, respectively, P < 0.05). During submaximal exercise, blood oxygen saturation improved at the Dead Sea compared with sea level at all exercise intensities (P < 0.05). In conclusion, these results suggest that even a brief stay at the Dead Sea area may have physiological benefits for CF patients with moderate to severe lung disease.
authors.affiliation: Ribstein Center for Sport Medicine Sciences and Research, Wingate Institute, Israel. bareket.falk@brocku.ca
authors.forename: Bareket
authors.initials: B
authors.lastname: Falk
authors.forename: Asaph
authors.initials: A
authors.lastname: Nini
authors.forename: Levana
authors.initials: L
authors.lastname: Zigel
authors.forename: Yaacov
authors.initials: Y
authors.lastname: Yahav
authors.forename: Micha
authors.initials: M
authors.lastname: Aviram
authors.forename: Joseph
authors.initials: J
authors.lastname: Rivlin
authors.forename: Lea
authors.initials: L
authors.lastname: Bentur
authors.forename: Avraham
authors.initials: A
authors.lastname: Avital
authors.forename: Raffy
authors.initials: R
authors.lastname: Dotan
authors.forename: Hannah
authors.initials: H
authors.lastname: Blau
mesh_terms: D000293:Adolescent; D000328:Adult; D000531:Altitude; D000704:Analysis of Variance; D000886:Anthropometry; D001274:Atmospheric Pressure; D018592:Cross-Over Studies; D003550:Cystic Fibrosis / Q000175:diagnosis* / Q000534:rehabilitation; D004734:Energy Metabolism; D005080:Exercise Test; D017079:Exercise Tolerance / Q000502:physiology*; D005260:Female; D006334:Heart Function Tests; D006339:Heart Rate; D006801:Humans; D007557:Israel; D008171:Lung Diseases / Q000175:diagnosis* / Q000534:rehabilitation; D008297:Male; D008875:Middle Aged; D010092:Oximetry; D010101:Oxygen Consumption / Q000502:physiology*; D018579:Patient Selection; D011336:Probability; D012129:Respiratory Function Tests; D012720:Severity of Illness Index