Prolonged endurance challenge at moderate altitude: effect on serum eosinophil cationic protein, eosinophil dynamics, and lung function

Eosinophil cationic protein (ECP) correlates with eosinophil cell counts in the induced sputum of elite swimmers

Introduction

Swimming practice has been associated with eosinophilic inflammation, however, the underlying mechanisms are not fully understood. The eosinophil cationic protein (ECP) in induced sputum may be used as a potential biomarker to assess airway eosinophilic inflammation among elite swimmers. The objective of this study is to characterize ECP levels in sputum supernatant in elite swimmers and evaluate ECP as an eosinophilic inflammatory marker.

Material and methods

Elite swimmers annually screened in our department (n = 27) were invited to participate in this cross-sectional study. Swimmers who agreed to participate (n = 24, 46% girls) performed lung function and skin-prick tests. Induced sputum was also collected and analyzed for differential cell counts and ECP measurements in sputum supernatant (ImmunoCAPTM 100, ECP, Thermo Fisher Scientific, Uppsala, Sweden).

Results

The median ECP level was 15.60 μg/L (6.02-38.75 μg/L) and higher levels were found among boys (27.90 (11.20-46.30) μg/L vs 6.65 (2.82-22.80) μg/L, P = .02). In addition, ECP levels in the sputum supernatant were positively correlated with eosinophil cell counts in the induced sputum (r = 0.583, P = .08).

Conclusions

ECP levels correlated positively with eosinophil counts in the induced sputum in elite swimmers. The measurement of ECP in sputum supernatant may be a useful marker to assess and manage eosinophilic inflammatory changes in the airways of elite swimmers.

Feasibility of exercising adults with asthma: a randomized pilot study

Background

Aerobic exercise appears to have clinical benefits for many asthmatics, yet a complete understanding of the mechanisms underlying these benefits has not been elucidated at this time.

Purpose

The objective of this study was to determine feasibility for a larger, future study that will define the effect of aerobic exercise on cellular, molecular, and functional measures in adults with mild-moderate asthma.

Design

Recruited subjects were randomized into usual care (sedentary) or usual care with moderate intensity aerobic exercise treatment groups.

Setting / Participants

Nineteen adults with mild-moderate asthma but without a recent history of exercise were recruited at the UAB Lung Health Center, Birmingham, AL.

Intervention

The exercise group underwent a 12 week walking program exercising at 60 – 75% of maximum heart rate (HR_max). Subjects self-monitored HR_max levels using heart rate monitors; exercise diaries and recreation center sign-in logs were also used.

Main outcome measures

Functional measures, including lung function and asthma control scores, were evaluated for all subjects at pre- and post-study time-points; fitness measures were also assessed for subjects in the exercise group. Peripheral blood and nasal lavage fluid were collected from all subjects at pre- and post-study visits in order to evaluate cellular and molecular measures, including cell differentials and eosinophilic cationic protein (ECP).

Results

Sixteen subjects completed the prescribed protocol. Results show that subjects randomized to the exercise group adhered well (80%) to the exercise prescription and exhibited a trend toward improved fitness levels upon study completion. Both groups exhibited improvements in ACQ scores. No changes were observed in lung function (FEV1, FEV1/FVC), cell differentials, or ECP between groups.

Conclusions

Results indicate that a moderate intensity aerobic exercise training program may improve asthma control and fitness levels without causing asthma deterioration in adult asthmatics. As such, these findings demonstrate the feasibility of the study protocol in preparation for a larger, clinical trial that will elucidate the functional consequences of aerobic exercise on asthmatic cellular and molecular responses.

Bronchial asthma: advice for patients traveling to high altitude

This article examines the possibility of traveling to altitude for patients suffering from bronchial asthma. The mountain environment, the adaptations of the respiratory system to high altitude, the underlying patho-physiologies of asthma, and the recommendations for patients, according to altitude, are discussed. In summary, staying at low altitude has a significant beneficial effect for asthmatic patients, due to the reduction of airway inflammation and the lower response to bronchoconstrictor stimuli; for staying at moderate altitude, there is conflicting information and no clinical data; at high altitude, the environment seems beneficial for well-controlled asthmatics, but intense exercise and upper airway infections (frequent during trekking) can be additional risks and should be avoided. Further, in remote areas health facilities are often difficult to reach.

Respiratory diseases and high altitude

The aim of this paper is to review how preexisting pulmonary diseases can be affected by altitude exposure. Obstructive (asthma and chronic obstructive pulmonary disease or COPD) and restrictive (interstitial pulmonary fibrosis), as well as pulmonary vascular diseases, will be considered, and the goal will be to provide insight and tools to clinicians to optimize the medical condition and thus the life-style of these patients. The underlying pathophysiologies and the effect of hypobaric hypoxia on these diseases will be reviewed such that techniques to assess patients will be appropriate. Therapeutic interventions, including the use of supplemental oxygen, in light of the underlying pathologic processes, will also be discussed.