Objectives: Sleep apnea is associated with advanced atherosclerosis. This study was focused on sleep breathing in patients with hemodynamically significant carotid stenosis, currently free from clinical symptoms.
Design and settings: 17 patients with carotid artery stenosis of 70% and more in the absence of actual neurological symptoms indicated for non-acute endarterectomy, and 17 age- and sex-matched controls were examined using sleep polygraphy. 12 patients had a follow-up sleep polygraphy a month after the surgery.
Results: The criteria of obstructive sleep apnea (OSA) were met by 4 patients prior to operation, by 2 patients after the operation, and by 2 control subjects. The pre-surgery apnea/hypopnea index (AHI) was 14 (+/-SD=17.0), post-surgery 8.3 (+/-9.0) and in the controls 6.7(+/-6.7). The pre-surgery oxygen desaturation index was 20.1 (+/-17.7), post-surgery 15.0 (+/-12.0) and in the controls 11.6 (+/-6.1). A comparison between the pre-surgery results seen in the patients and in controls after adjustment for BMI revealed no significant difference. The only significant difference between the pre-surgery and post-surgery values was found in the AHI (P=0.045).
Conclusion: According to this study there exists an association between carotid stenosis and OSA, however this association is explainable by a higher BMI. The study also found a tendency toward OSA alleviation in response to endarterectomy.