Central sleep apnea is associated with increased risk of ischemic stroke in the elderly.

OBJECTIVES

Sleep apnea/hypopnea syndrome is a well-recognized independent risk factor for stroke in middle-aged population, but controversy remains in older subjects. We examined the possible association between different respiratory parameters and risk of stroke in a prospective population-based cohort of 394 stroke-free elderly subjects.

MATERIAL AND

METHODS

Fully overnight polysomnography was performed at baseline. Over the 6 year follow-up period, 20 ischemic strokes occurred. Differences in stroke-free survival between subjects according to central apnea index (CAI) were assessed.

RESULTS

We just observed association with incident ischemic stroke on central sleep apnea (CSA) episodes. Obstructive sleep apnea, time passed under 90% oxygen saturation, or arousal index were not associated. The event-free survival was lowest in the highest CAI group. This association was independent of any other vascular risk factors.

CONCLUSIONS

CSA is the specific respiratory event associated with stroke in the elderly. Additionally, CSA could be a marker of silent brain ischemia, as a sign of disturbed regulation of central respiratory mechanisms, tentatively of ischemic origin.