Increased prevalence of sleep apnea in patients with recurring ischemic stroke compared with first stroke victims

Abstract

Since sleep apnea (SA) and stroke have many shared risk factors an independent contribution of SA to the overall risk of stroke is not easily proven and has been questioned recently. To contribute to this controversy, we analysed the frequency of SA in groups of patients with first and recurring ischemic stroke. We prospectively studied 102 patients admitted to our stroke unit. The prevalence of vascular risk factors and a history of previous stroke were recorded. All patients received cardio-respiratory polygraphy during the first 72 hours after admission. CT and MRI scans were evaluated for the location of the acute stroke and the presence of older vascular lesions. Thirty-four women and 68 men with a mean age of 64.5 +/- 13.7 years were included in the study. Cerebral lesions attributable to a previous stroke were identified in 25 patients, of whom 19 reported to have suffered a stroke before. Patients with stroke recurrence had a higher mean apnea-hypopnea index (AHI) (26.6/h vs. 15.1/h, p<0.05) and more often presented with a sleep apnea syndrome (SA) defined by an AHI >or=10/h (80 vs. 52%, p < 0.05) than patients with first ever stroke. Logistic regression analysis including the variables "age", "gender", "cumulative risk factors", "AHI >or=10/h", and "diabetes" identified diabetes (Odd's ratio [OR]=4.5) and AHI >or=10/h (OR=3.5) as independent risk-factors for stroke recurrence. According to our results SA is an independent risk factor for stroke recurrence. We therefore advocate routine sleep-apnea screening in all patients having suffered an ischemic stroke.

Nocturnal Desaturation in the Stroke Unit Is Associated With Wake-Up Ischemic Stroke

“…7,12,13,[29][30][31] NOD secondary to sleepdisordered breathing could be a modifiable risk factor for stroke and other cardiovascular diseases. 32,33 Lifestyle modification, such as weight-loss intervention, may help improve sleep-disordered breathing symptom and may possibly lead to stroke prevention. 23,34,35 In addition, long-term continuous positive airway pressure treatment, the representative treatment of sleep apnea, is considered to provide protection against stroke in patients with sleep-disordered breathing.…”

The Effect of Sleep Disordered Breathing on the Outcome of Stroke and Transient Ischemic Attack: A Systematic Review

“…Study characteristics and main results for these are presented in Table 1. Six studies were European [22][23][24][25][26][27] and two were North American. 19,20 The sample sizes were small, ranging from 47 to 174 stroke or TIA patients.…”

“…The study designs included seven prospective cohort studies 19,20,[23][24][25][26][27] and one cross-sectional study. 22 Two studies presented stroke recurrence as a primary outcome, 22,25 five studies addressed all-cause mortality as primary outcome, 19,20,23,26,27 and one study evaluated both fatal and nonfatal cardiovascular events. 24 Two studies had case-fatality as secondary outcomes.…”

“…20,25 The definition of SDB varied from AHI of 5 events/hour to 20 events/hour. An apnea episode was defined as 10 seconds of cessation of airflow, 22,23,26,27 > 75% decrease, 24 or > 50% decrease in airflow. 25 A hypopnea was defined as a 25% to 50%, 24 ≥ 50%, 22,26,27 or a discernible 23 or clear 25 reduction in airflow or thoraco-abdominal amplitude for ≥ 10 seconds.…”

“…24 In a cross-sectional study, Dziewas et al showed a dose-response relation between the severity of SDB and the risk of stroke recurrence. 22 Six cohort studies have addressed the relationship between SDB and all-cause mortality 19,20,23,26,27 or fatal cardiovascular events. 24 Three of these studies found an exposure-dependent relationship between the severity of SDB and risk of death, within six months, 27 two years, 23 and 10 years 26 follow-up.…”