Autonomic function may not modulate irisin release in healthy adults: findings from a randomized cross-over study

Area of Science:

• Exercise Physiology
• Endocrinology
• Autonomic Neuroscience

Background:

• The sympathetic nervous system may influence irisin, a hormone regulating metabolism.
• Irisin's release is known to increase following acute exercise.
• The relationship between autonomic function and exercise-induced irisin release requires further investigation.

Purpose of the Study:

• To investigate the association between autonomic function, assessed via heart rate indices, and irisin release after acute exercise.
• To compare exercise-induced irisin release and autonomic responses between cycling and running protocols.

Main Methods:

• Seventeen healthy adults completed incremental exhaustive cycling and running sessions on separate days.
• Heart rate was monitored throughout exercise and recovery.
• Serum irisin levels were measured pre-exercise and at 0, 10, and 60 minutes post-exercise using ELISA.

Main Results:

• Heart rate parameters (rest, peak, recovery, reserve, chronotropic index) were similar between cycling and running.
• Serum irisin levels significantly increased immediately post-exercise for both modalities.
• No significant correlations were found between autonomic function markers and irisin levels or exercise-induced irisin release.

Conclusions:

• Autonomic function, as assessed by heart rate variability and other indices, does not appear to be associated with irisin release in healthy adults following acute exercise.
• These findings suggest that exercise-induced irisin release may be independent of autonomic nervous system modulation in this population.