Sleep disordered breathing in chronic obstructive pulmonary disease.

Area of Science:

• Pulmonary Medicine
• Sleep Medicine
• Cardiorespiratory Physiology

Background:

• Sleep disordered breathing (SDB) is common in patients with chronic obstructive pulmonary disease (COPD).
• The impact of chronic respiratory failure (CRF) on SDB in COPD patients requires further investigation.
• Obesity is a known risk factor for SDB, but its specific role in COPD patients with and without CRF is not fully elucidated.

Purpose of the Study:

• To prospectively investigate sleep disordered breathing (SDB) in patients with COPD.
• To compare SDB parameters between COPD patients with and without chronic respiratory failure (CRF).
• To determine the association between body mass index (BMI), neck circumference, and SDB indicators in COPD patients.

Main Methods:

• Prospective study involving polysomnography in 50 consecutive COPD patients.
• Patients were categorized into groups with (n=33) and without (n=17) CRF.
• Analysis included nocturnal oxygen saturation (SaO2), FEV1, PEFR, and apnea-hypopnea index (AHI), correlated with BMI and neck circumference.

Main Results:

• COPD patients with CRF exhibited significantly lower mean and minimal nocturnal SaO2 compared to those without CRF.
• Patients with CRF also showed lower FEV1 and PEFR, suggesting a link to oxygen saturation levels.
• A significant positive correlation was found between AHI and neck circumference (r=0.41; p=0.005), and a trend with BMI (r=0.31).
• Only three patients had a significant AHI, all with higher BMIs (mean 27.7).

Conclusions:

• Body mass index (BMI) plays a role in the apnea-hypopnea index (AHI) and nocturnal desaturation in COPD patients.
• CRF is associated with more severe nocturnal oxygen desaturation in COPD.
• While AHI was not significantly elevated overall, BMI is a contributing factor to SDB and desaturation in this population.