Treatment

If patients do not experience less sleepiness after a period of time and are still complying with the regimen, then the airflow pressure may not be high enough. Patients may require retesting. Many patients report feeling more alert after CPAP treatments even if objective laboratory tests fail to show significant differences in the number of apneas and wake-up periods.

Protection from Accidents. Studies suggest that treatment with CPAP can reduce the risk for accidents. In a 2001 study, untreated patients had a risk for automobile accidents that was three times the risk in the general population. When these patients were treated, their risk fell to normal.

Effects on the Heart and Circulation. Evidence is mixed on whether CPAP treatment may reduce serious heart conditions. Early studies suggested that CPAP could improve heart function, lower blood pressure, and prevent new cardiac events (such as heart attacks) in patients with congestive heart failure and coronary artery disease. However, a 2005 study in the New England Journal of Medicine found that, while CPAP helped improve some heart disease symptoms, it did not affect overall survival in patients with heart failure and central sleep apnea. (Patients with heart failure often have central sleep apnea.)

It is also unclear whether CPAP improves blood pressure. A 2006 study of patients with high blood pressure and sleep apnea indicated that short-term (4 weeks) CPAP treatment has no significant effect on lowering blood pressure. (It is possible that longer-term treatment may be helpful.) Other studies have found blood pressure benefits from short-term CPAP treatment. Treatment for sleep apneas must be very effective, however, to have any benefits on blood pressure. Even a 50% reduction in apneas has no effect.

Effects on Other Medical Conditions. Some studies suggest other benefits with the use of CPAP:

• Fewer morning headaches
• Reduction in abdominal fat (abdominal fat has been related to a higher risk for diabetes and heart disease.)
• Lower blood sugar levels in patients with type 2 diabetes
• Improved thinking and concentration in people with impaired mental function from sleep apnea
• Modest lung improvement in patients with both apnea and chronic obstructive lung disease (such as emphysema)