Blood pressure perturbations caused by subclinical sleep-disordered breathing

Area of Science:

• Cardiovascular Physiology
• Sleep Medicine
• Respiratory Physiology

Background:

• Sleep-disordered breathing (SDB) affects a significant portion of the adult population.
• The acute cardiovascular effects of SDB events like apneas and hypopneas are not fully understood in non-clinical populations.
• Hypertension is a prevalent health concern, and its link to subclinical SDB warrants investigation.

Purpose of the Study:

• To investigate the immediate impact of apneas and hypopneas on blood pressure in middle-aged adults.
• To identify factors predicting the blood pressure response to SDB events.
• To explore the potential role of these acute blood pressure changes in the development of hypertension.

Main Methods:

• Noninvasive arterial pressure monitoring using photoelectric plethysmography during overnight polysomnography.
• Analysis of 272 apneas and 1469 hypopneas in 95 participants (72 men, 23 women) from the Wisconsin Sleep Cohort Study.
• Correlation of blood pressure changes with oxygen saturation, event duration, heart rate, ventilatory overshoot, and electroencephalographic arousal.

Main Results:

• Both apneas and hypopneas, even with mild oxygen desaturation, led to a decrease in blood pressure during the event.
• A significant increase in blood pressure was observed during the post-event recovery period (peak changes: 23+/-10 mm Hg systolic, 13+/-6 mm Hg diastolic).
• Ventilatory overshoot, event length, heart rate changes, oxygen desaturation, and electroencephalographic arousal were significant predictors of pressor responses.

Conclusions:

• Acute SDB events cause distinct blood pressure fluctuations (decrease during event, increase post-event).
• These transient blood pressure changes are influenced by multiple physiological factors.
• Subclinical SDB-related blood pressure variability may contribute to the pathogenesis of hypertension.