Influence of testosterone on breathing during sleep

Area of Science:

• Sleep Medicine
• Endocrinology
• Respiratory Physiology

Background:

• Sleep-related breathing disorders, including apneas and hypopneas, are more prevalent in men.
• Previous observations suggest testosterone administration may exacerbate disordered breathing in hypogonadal men, indicating a potential hormonal link.

Purpose of the Study:

• To investigate the effect of testosterone replacement therapy on respiratory patterns during sleep in hypogonadal males.
• To determine if hormonal influences on sleep-disordered breathing are mediated by changes in upper airway anatomy.

Main Methods:

• Studied 11 hypogonadal males on and off testosterone-replacement therapy, monitoring respiratory rhythm during sleep.
• Assessed upper airway anatomy (CT scan) and airflow resistance in four subjects under both conditions.
• Analyzed sleep stage distribution, duration, and the frequency of apneas and hypopneas.

Main Results:

• Testosterone administration did not alter sleep stage distribution or duration.
• A significant increase in both apneas and hypopneas was observed during testosterone replacement (from 6.4 ± 2.1 to 15.4 ± 7.0 events/hour, P < 0.05).
• Upper airway dimensions and airflow resistance remained unchanged, indicating testosterone's effect is independent of these anatomical factors.

Conclusions:

• Testosterone replacement therapy significantly exacerbates sleep-disordered breathing in hypogonadal men.
• The mechanism by which testosterone influences sleep-disordered breathing appears to be independent of structural changes in the upper airway.
• Hormonal factors, specifically testosterone, play a role in regulating respiratory control during sleep.