Evolution of mild obstructive sleep apnea after different treatments.

STUDY

OBJECTIVES

To evaluate the prognosis of mild obstructive sleep apnea in relation to different treatment modalities.

STUDY

DESIGN

An open, retrospective, longitudinal follow-up study.

METHODS

Fifty adult patients diagnosed and treated for mild obstructive sleep apnea at the Department of Otorhinolaryngology at Kuopio University Hospital between 1998 and 2004 had a control polysomnography in 2005. The changes in apnea-hypopnea index (AHI) were observed in untreated (n = 28), operative (n = 11), and continuous positive airway pressure (n = 11) treatment groups at a long-term follow-up visit.

RESULTS

The mean follow-up period was 4 (range, 1.3-9.0; SD, 1.9) years. The untreated patients had a statistically significant increase in AHI (13.3, SD 18.3) at the follow-up. Half of these patients developed a moderate or severe degree of sleep apnea, and only 11% were cured. In patients who were treated with continuous positive airway pressure, the degree of obstructive sleep apnea became worse in 64% of cases, and in 27% of patients, the AHI returned to normal (<5). The degree of obstructive sleep apnea in operated patients deteriorated only in 18%, and in 27% of the patients, the AHI returned to normal (<5).

CONCLUSIONS

Mild obstructive sleep apnea has a natural tendency to worsen with time. Active treatment of mild obstructive sleep apnea appears, therefore, to be advisable.