Effects of mass loading on the upper airway

Area of Science:

• Respiratory physiology
• Otorhinolaryngology
• Sleep medicine

Background:

• Obesity is linked to obstructive sleep apnea (OSA).
• Cervical adipose tissue accumulation is a characteristic of obesity.
• The impact of increased cervical fat on upper airway function is not fully understood.

Purpose of the Study:

• To investigate how increased cervical adipose tissue affects upper airway dimensions, stability, and resistance.
• To determine the relationship between mass loading of the neck and upper airway function.

Main Methods:

• Eight rabbits were studied under anesthetized and postmortem conditions.
• Lard-filled bags simulated cervical fat accumulation, applying mass loads to the upper airway.
• Upper airway resistance and closing pressure were measured before and after loading.
• Endoscopy assessed pharyngeal dimensions and airway configuration.

Main Results:

• Mass loading caused concentric narrowing of the pharynx.
• Upper airway resistance significantly increased with applied loads.
• Airway stability decreased, as indicated by reduced closing pressures.
• The thyrohyoid membrane area was particularly susceptible to mass loading effects.

Conclusions:

• Simulated cervical fat accumulation alters upper airway configuration and function.
• Mass loading of the upper airway contributes to increased resistance and reduced stability.
• These findings suggest a potential role for cervical adipose tissue in the pathogenesis of obstructive sleep apnea (OSA) associated with obesity.