Does Pulmonary Function Testing Affect Autonomic Nervous System Activity?

Area of Science:

• Physiology
• Autonomic Nervous System Research
• Pulmonary Function Testing

Background:

• The autonomic nervous system (ANS) regulates critical physiological functions, including heart rate and respiration.
• Pulmonary function tests (PFTs) involve forced breathing maneuvers that may influence ANS activity and the accuracy of autonomic measurements.
• Heart rate variability (HRV) is a key indicator of ANS activity.

Purpose of the Study:

• To investigate the acute effects of PFTs on ANS activity.
• To evaluate the reliability of HRV measurements in relation to PFTs.
• To determine the optimal timing for autonomic function assessment.

Main Methods:

• Forty-eight healthy university students underwent HRV assessment using the Elite HRV Corsense device.
• HRV was recorded at rest (two measurements) and after completing PFTs with a Medwelt SP10 spirometer.
• Analysis focused on changes in HRV parameters, including RMSSD, LF, HF, and LF/HF ratio.

Main Results:

• A significant increase in RMSSD was observed between the first and second resting measurements, indicating improved parasympathetic activity after a short rest.
• No significant changes in average heart rate or RMSSD were found between the second resting measurement and the post-PFT measurement.
• Significant alterations in low-frequency (LF) and high-frequency (HF) components, along with the LF/HF ratio, were detected after PFT, suggesting a shift in autonomic balance.

Conclusions:

• Respiratory maneuvers during PFTs can transiently affect ANS activity, particularly the sympathetic-parasympathetic balance.
• Adequate rest is crucial for reliable HRV assessment, as evidenced by the differences between initial resting measurements.
• Autonomic function assessments are more accurate when conducted before PFTs.