Nocturnal Blood Pressure Variability in Patients with Obstructive Sleep Apnea Syndrome

Area of Science:

• Cardiology
• Sleep Medicine
• Respiratory Medicine

Background:

• Obstructive sleep apnea (OSA) is a prevalent respiratory disorder frequently associated with hypertension and cardiovascular issues.
• Elevated blood pressure variability is recognized as a potential indicator of cardiovascular event risk.

Purpose of the Study:

• To investigate the association between severe obstructive sleep apnea (OSA) and heightened blood pressure variability.
• To determine if severe OSA is an independent risk factor for increased blood pressure fluctuations.

Main Methods:

• Respiratory polygraphy was used to classify 58 patients into severe OSA (apnea/hypopnea index > 29/h) and mild-to-moderate OSA (AHI 5-30/h) groups.
• 24-hour noninvasive blood pressure monitoring was conducted to assess blood pressure variability using standard deviation.

Main Results:

• Patients with severe OSA exhibited significantly higher mean nocturnal systolic (133.2 vs. 117.7 mmHg) and diastolic blood pressure (80.9 vs. 73.8 mmHg) compared to those with mild-to-moderate OSA.
• Nocturnal systolic (12.1 vs. 7.6 mmHg) and diastolic blood pressure variability (10.5 vs. 7.3 mmHg) were markedly increased in the severe OSA group.
• Mean nocturnal blood pressure variability was also higher in severe OSA patients (9.1 vs. 6.8 mmHg).

Conclusions:

• Severe OSA is associated with elevated nocturnal blood pressure levels.
• Increased nocturnal blood pressure variability is a significant finding in patients with severe OSA.
• Both higher nocturnal blood pressure and increased blood pressure variability in severe OSA may serve as risk factors for cardiovascular complications.