Exhaled Particles After a Standardized Breathing Maneuver.

Area of Science:

• Respiratory physiology
• Pulmonary diagnostics

Background:

• Particles in exhaled air (PEx) reflect respiratory tract lining fluid.
• PEx originate from small airway reopening and contain surfactant.
• Significant interindividual variation in PEx exists, even with standardized breathing.

Purpose of the Study:

• To determine if sex, age, body size, and spirometry explain PEx variation.
• To investigate predictors of interindividual differences in PEx among healthy adults.

Main Methods:

• PEx measured using the PExA instrument in 126 healthy middle-aged adults.
• Standardized breathing maneuver: full expiration, breath-hold, full inspiration, full expiration.
• Analysis of age, anthropometric, and spirometric variables as predictors.

Main Results:

• PEx per liter (PEx/L) negatively correlated with lung size, lower in men than women.
• PEx per exhalation was similar between sexes.
• Increasing age correlated with increasing PEx.
• Predictors explained 28-29% of interindividual variation.

Conclusions:

• Large interindividual variation in PEx persists after standardization.
• Sex, age, body size, and spirometry explain only a minor part of this variation.