Can central adiposity increase obstructive sleep-disordered breathing risk during sleep, especially in older men?

Central adiposity significantly impairs respiratory mechanics during sleep, escalating the risk of obstructive sleep-disordered breathing (SDB). This relationship is particularly pronounced in older men due to a combination of anatomical, mechanical, and age-related physiological shifts.

Mechanical and physiological pathways

• Diaphragmatic displacement: Visceral fat accumulation increases intra-abdominal pressure, especially in the supine position. This pressure forces the diaphragm cranially, restricting lung expansion and significantly reducing resting lung volumes, specifically Functional Residual Capacity (FRC).
• Loss of tracheal traction: Reduced FRC diminishes the downward axial pull—known as caudal tracheal traction—on pharyngeal tissues. Loss of this stabilizing physical tension decreases pharyngeal wall stiffness, rendering the upper airway floppy and highly susceptible to collapse.
• Anatomical crowding: Direct fat deposition within the neck and pharyngeal walls structurally narrows the airway lumen, increasing tissue pressure and compounding mechanical obstruction when muscle tone drops at sleep onset.

Clinical implications for older men

• Beyond BMI: In older cohorts, regional central fat distribution and male sex serve as stronger, independent predictors of severe obstructive sleep apnea (OSA) than Body Mass Index (BMI) alone.
• Compounded risk: The age-related decline in upper airway dilator muscle tone, combined with male-pattern visceral adiposity, significantly lowers the structural threshold for airway collapse, leading to more severe SDB presentations.

Bottom line

• Central adiposity drives airway collapse through a dual mechanical pathway of diaphragmatic compression and lost caudal tracheal traction. In older males, localized visceral fat is a crucial, BMI-independent determinant of severe sleep apnea that requires targeted clinical attention.