Exhaled breath temperature increases after exercise in asthmatics and controls

Area of Science:

• Respiratory Medicine
• Pulmonary Physiology

Background:

• Exhaled breath temperature (EBT) is a potential non-invasive biomarker for airway inflammation in asthma.
• Understanding EBT's response to physiological challenges like exercise is crucial for asthma management.

Purpose of the Study:

• To evaluate EBT changes in asthma patients versus healthy individuals following an exercise challenge.
• To compare EBT in subjects with and without exercise-induced bronchoconstriction.
• To correlate EBT with core and peripheral body temperatures.

Main Methods:

• Inclusion of 21 healthy controls and 20 asthma patients.
• Measurement of forced expiratory volume in 1 second (FEV(1)), EBT, and oral, axillary, and auricular temperatures before and after exercise.
• Analysis of EBT changes and correlation with lung function parameters.

Main Results:

• Asthma patients exhibited significantly lower FEV(1)% predicted post-exercise compared to controls.
• EBT increased markedly 5 minutes after exercise and remained elevated for at least 60 minutes.
• Higher EBT at 60 minutes post-exercise was observed in asthmatics with a >10% drop in FEV(1)%p, correlating with oral and axillary temperatures.

Conclusions:

• Exercise challenge leads to increased EBT, which correlates with reduced FEV(1)%p in asthma.
• While initial EBT increases were similar between groups, sustained elevation in specific asthma subgroups suggests distinct vascular responses.
• EBT shows potential as a monitoring tool for exercise-induced airway changes in asthma.