Long-term nasal CPAP does not ameliorate obstructive sleep apnoea

Area of Science:

• Pulmonary and Sleep Medicine
• Cardiovascular Medicine

Background:

• Obstructive sleep apnoea (OSA) is a common condition associated with significant health risks.
• Continuous positive airway pressure (CPAP) is a primary treatment for OSA, but long-term effects require further investigation.

Purpose of the Study:

• To evaluate the long-term efficacy of nasal CPAP in patients with OSA.
• To assess changes in OSA severity, oxygen saturation, BMI, and blood pressure after at least six months of CPAP treatment.

Main Methods:

• Fifty-seven OSA patients treated with nasal CPAP for ≥6 months underwent follow-up sleep studies.
• OSA severity (Apnoea-Hypopnoea Index - AHI) and minimum oxygen saturation were compared between initial diagnostic studies and follow-up (without CPAP for the first half of the night).
• Body Mass Index (BMI) and arterial blood pressure were also assessed before and after treatment.

Main Results:

• A non-significant fall in AHI (41.4 to 34.8, p=0.06) and a significant rise in minimum oxygen saturation (71.6% to 78.5%, p<0.001) were observed.
• Reduced REM sleep at follow-up may have influenced results (p<0.05).
• No significant reduction in BMI (p=0.39) or diastolic blood pressure (p=0.11) was found, but systolic blood pressure decreased (p<0.05).

Conclusions:

• Long-term nasal CPAP treatment resulted in marginal clinical improvements in AHI and minimum oxygen saturation, potentially artefactual.
• CPAP therapy did not lead to significant weight loss or improvements in diastolic blood pressure in this cohort.