Cardiovascular reflexes in workers exposed to hand-arm vibration

Area of Science:

• Occupational Health
• Cardiovascular Physiology
• Autonomic Nervous System Function

Background:

• Hand-arm vibration (HAV) is prevalent in occupations like lumberjacking and railroad work.
• Vibration-induced white finger (VWF) is a known consequence of prolonged HAV exposure.
• Autonomic nervous system (ANS) function plays a crucial role in cardiovascular regulation.

Purpose of the Study:

• To investigate the impact of long-term hand-arm vibration exposure on cardiovascular reflexes.
• To assess whether HAV exposure leads to autonomic dysfunction in exposed workers.
• To compare autonomic function in HAV-exposed workers with primary Raynaud's cases.

Main Methods:

• Cardiovascular reflexes were measured using the quiet breathing test, deep breathing test, and Valsalva manoeuvre.
• The study included 47 workers exposed to hand-arm vibration (lumberjacks, railroad workers).
• A subgroup of 36% of subjects presented with vibration-induced white finger (VWF); 5 primary Raynaud's cases were included for comparison.

Main Results:

• No general autonomic dysfunction was evidenced due to hand-arm vibration exposure.
• A reduction in autonomic function was observed in workers susceptible to developing vibration-induced white finger (VWF).
• Age showed a significant negative correlation with R-R interval changes during breathing tests, indicating an age-related decline in autonomic response.

Conclusions:

• Hand-arm vibration exposure does not appear to cause widespread autonomic dysfunction.
• HAV may reduce autonomic function in individuals prone to developing vibration-induced white finger (VWF).
• Reduced cardiovascular reflex responses may also be present in primary Raynaud's cases.