Autonomic neuropathy and vibration exposure in forestry workers

Area of Science:

• Occupational Health
• Autonomic Nervous System Function
• Cardiovascular Physiology

Background:

• Heart rate variability (HRV) reflects autonomic nervous system (ANS) balance.
• Occupational exposure to vibration, particularly from chainsaws, is common among lumberjacks.
• Previous research suggests potential links between vibration exposure and physiological changes.

Purpose of the Study:

• To investigate the association between prolonged chainsaw vibration exposure and heart rate variability in professional lumberjacks.
• To assess the impact of vibration on parasympathetic nervous system activity.
• To determine if vibration exposure contributes to autonomic dysfunction.

Main Methods:

• Studied 88 professional lumberjacks using computer-based heart rate variability analysis.
• Measured HRV at rest and during deep breathing tests (6 cycles/minute).
• Calculated traditional HRV indexes (CV, CVS, MEAN) and spectral components (frequency related power - FRP).

Main Results:

• Significant differences in HRV indexes were found between lumberjacks with shortest and longest vibration exposures (p < 0.001).
• HRV indexes decreased with age, with total vibration exposure time showing an independent negative association with HRV.
• All frequency bands of heart rate showed significant differences between exposure groups, suggesting impaired parasympathetic activity.

Conclusions:

• Prolonged chainsaw vibration exposure negatively affects parasympathetic nervous system activity.
• The findings suggest that occupational vibration exposure leads to autonomic dysfunction in lumberjacks.
• HRV during deep breathing tests can serve as an indicator of vibration-induced autonomic dysfunction.