Longitudinal Assessment of Sleep Apnea in the Year After Stroke in a Population-Based Study.

BACKGROUND: The aim of this study was to characterize change in sleep-disordered breathing severity in the year following stroke, overall, and by ethnicity, within the population-based Brain Attack Surveillance in Corpus Christi Project. METHODS: First-ever ischemic strokes (n=414) were ascertained by active and passive surveillance and validated by stroke-trained physicians. Patients with stroke were invited to participate in portable sleep apnea testing (ApneaLink Plus) at baseline and 3, 6, and 12 months poststroke. Sleep-disordered breathing severity was assessed by the respiratory event index (apneas and hypopneas/hour of recording). The component obstructive apnea index and central apnea index were also assessed. Time and ethnicity effects on outcomes, as well as ethnic differences in time effects, were analyzed using generalized estimating equations with multivariable adjustment for confounding factors. RESULTS: Mean age (n=414) was 63.9 years (SD=10.9); 68.4% were Mexican American. Baseline mean respiratory event index, obstructive apnea index, and central apnea index were 21.3 (SD=16.6), 8.6 (SD=11.5), and 1.5 (SD=3.2), respectively. There was no time effect on respiratory event index (P=0.35) but obstructive apnea index increased over time (P<0.01). Averaged over follow-up, respiratory event index and obstructive apnea index were significantly higher in Mexican American than non-Hispanic White persons. No ethnic difference in the time effect was found for either outcome. For central apnea index, there was an ethnicity-time interaction (P=0.01) such that central apnea index increased in non-Hispanic White but did not change in Mexican American persons. CONCLUSIONS: Sleep-disordered breathing severity was significant and stable for most individuals in the year after stroke. These results do not confirm previous reports of diminishing sleep-disordered breathing severity over time after stroke and would support early assessment and treatment where indicated.

Sleep-disordered breathing and poststroke outcomes.

OBJECTIVE: To examine the association between sleep-disordered breathing and stroke outcomes, and determine the contribution of sleep-disordered breathing to outcome disparities in Mexican Americans. METHODS: Ischemic stroke patients (n = 995), identified from the population-based Brain Attack Surveillance in Corpus Christi Project (2010-2015), were offered participation in a sleep-disordered breathing study including a home sleep apnea test (ApneaLink Plus). Sleep-disordered breathing (respiratory event index ≥10) was determined soon after stroke. Neurologic, functional, cognitive, and quality of life outcomes were assessed at 90 days poststroke. Regression models were used to assess associations between sleep-disordered breathing and outcomes, adjusted for sociodemographics, prestroke function and cognition, health-risk behaviors, stroke severity, and vascular risk factors. RESULTS: Median age was 67 years (interquartile range [IQR] = 59-78); 62.1% were Mexican American. Median respiratory event index was 14 (IQR = 6-25); 62.8% had sleep-disordered breathing. Sleep-disordered breathing was associated with worse functional outcome (mean difference in activities of daily living/instrumental activities of daily living score = 0.15, 95% confidence interval [CI] = 0.01-0.28) and cognitive outcome (mean difference in modified Mini-Mental State Examination = -2.66, 95% CI = -4.85 to -0.47) but not neurologic or quality of life outcomes. Sleep-disordered breathing accounted for 9 to 10% of ethnic differences in functional and cognitive outcome and was associated with cognitive outcome more strongly for Mexican Americans (ß = -3.97, 95% CI = -6.63 to -1.31) than non-Hispanic whites (ß = -0.40, 95% CI = -4.18 to 3.39, p-interaction = 0.15). INTERPRETATION: Sleep-disordered breathing is associated with worse functional and cognitive function at 90 days poststroke. These outcomes are reasonable endpoints for future trials of sleep-disordered breathing treatment in stroke. If effective, sleep-disordered breathing treatment may somewhat lessen ethnic stroke outcome disparities. ANN NEUROL 2019;86:241-250.

Sleep-Disordered Breathing Is Associated With Recurrent Ischemic Stroke.

Background and Purpose- Limited data are available about the relationship between sleep-disordered breathing (SDB) and recurrent stroke and mortality, especially from population-based studies, large samples, or ethnically diverse populations. Methods- In the BASIC project (Brain Attack Surveillance in Corpus Christ), we identified patients with ischemic stroke (2010-2015). Subjects were offered screening for SDB with the ApneaLink Plus device, from which a respiratory event index (REI) score ≥10 defined SDB. Demographics and baseline characteristics were determined from chart review and interview. Recurrent ischemic stroke was identified through active and passive surveillance. Cause-specific proportional hazards models were used to assess the association between REI (modeled linearly) and ischemic stroke recurrence (as the event of interest), and all-cause poststroke mortality, adjusted for multiple potential confounders. Results- Among 842 subjects, the median age was 65 (interquartile range, 57-76), 47% were female, and 58% were Mexican American. The median REI score was 14 (interquartile range, 6-26); 63% had SDB. SDB was associated with male sex, Mexican American ethnicity, being insured, nonsmoking status, diabetes mellitus, hypertension, lower educational attainment, and higher body mass index. Among Mexican American and non-Hispanic whites, 85 (11%) ischemic recurrent strokes and 104 (13%) deaths occurred, with a median follow-up time of 591 days. In fully adjusted models, REI was associated with recurrent ischemic stroke (hazard ratio, 1.02 [hazard ratio for one-unit higher REI score, 95% CI, 1.01-1.03]), but not with mortality alone (hazard ratio, 1.00 [95% CI, 0.99-1.02]). Conclusions- Results from this large population-based study show that SDB is associated with recurrent ischemic stroke, but not mortality. SDB may therefore represent an important modifiable risk factor for poor stroke outcomes.

Wake-up stroke is not associated with sleep-disordered breathing in women.

BACKGROUND: We sought to investigate the frequency of wake-up stroke (WUS) and its association with sleep-disordered breathing (SDB) in women. METHODS: Within a population-based study, women with acute ischemic stroke were asked about their stroke symptom onset time. SDB screening was performed with the well-validated ApneaLink Plus device; SDB was defined by a respiratory event index ≥10. Logistic regression was used to test the association between SDB presence and severity and WUS unadjusted and adjusted for potential confounders including prestroke depression and sleep duration. RESULTS: Among 466 participants, the median age was 67.0 years (interquartile range [IQR] 58.0, 77.0), 55% were Mexican American, and the median initial NIH Stroke Scale score was 3.0 (IQR 1.0, 6.0). Stroke symptom onset occurred during nocturnal sleep (25.3%), during a nap (3.9%), during wakefulness (65.9%), or unknown (4.9%). In those with SDB screening performed (n = 259), a median of 11 days (IQR 5, 17) poststroke, WUS was not associated with the presence or severity (respiratory event index) of SDB in unadjusted or adjusted analysis. CONCLUSIONS: In this population-based study, WUS represented about 30% of all generally mild severity ischemic strokes in women and was not associated with SDB.

Intracerebral hemorrhage and sleep-disordered breathing.

OBJECTIVE/BACKGROUND: Limited data are available on sleep-disordered breathing (SDB) following intracerebral hemorrhage (ICH). Our aim was to characterize the objective measures of post-ICH SDB and questionnaire-reported pre-ICH sleep characteristics, overall and by ethnicity. PATIENTS/METHODS: Participants with ICH who were enrolled in the population-based Brain Attack Surveillance in Corpus Christi project (2010-2016) reported their pre-ICH sleep duration and completed the Berlin Questionnaire to characterize pre-ICH risk of SDB. A subsample was screened for SDB (respiratory event index ≥10) using ApneaLink Plus portable monitoring. Ethnic differences in post-ICH SDB or questionnaire-reported pre-ICH sleep characteristics were assessed using a log binomial model or a linear regression model or a Fisher's exact test. RESULTS: ICH cases (n = 298) were enrolled (median age = 68 years, 67% Mexican American). Among 62 cases with complete ApneaLink data, median time to post-ICH SDB screening was 11 days (IQR: 6, 19). Post-ICH SDB prevalence was 46.8% (95% CI: 34.4-59.2), and this rate did not differ by ethnicity (p = 1.0). Berlin Questionnaires for 109 of the 298 ICH cases (36.6% (95% CI: 31.1-42.0)) suggested a high risk for pre-ICH SDB, and the median pre-ICH sleep duration was eight hours (IQR: 6, 8). After adjusting for confounders, there was no difference in ethnicity in high risk for pre-ICH SDB or pre-ICH sleep duration. CONCLUSIONS: Nearly half of the patients had objective confirmation of SDB after ICH, and more than one-third had questionnaire evidence of high risk for pre-ICH SDB. Opportunities to address SDB may be common both before and after ICH.

High prevalence of poststroke sleep-disordered breathing in Mexican Americans.

OBJECTIVE: The purpose of this study is to compare sleep-disordered breathing (SDB) prevalence and severity after stroke between Mexican Americans (MAs) and non-Hispanic whites (NHWs). PATIENTS/METHODS: Ischemic stroke (IS) patients within ∼30 days of onset were identified from the population-based BASIC Project (2010-2014) and offered screening with an overnight cardiopulmonary monitoring device, ApneaLink Plus™. The number of apneas and hypopneas per hour, as reflected by the apnea/hypopnea index (AHI), was used to measure SDB severity; SDB was defined as AHI ≥10. Ethnicity, demographics, and risk factors were collected from interviews and medical records. Log and negative-binomial regression models were used to determine prevalence ratios (PRs) and apnea/hypopnea event rate ratios (RRs) comparing MAs with NHWs after adjustment for demographics, risk factors, and stroke severity. RESULTS: A total of 549 IS cases had AHI data. The median age was 65 years (interquartile range (IQR): 57-76), 55% were men, and 65% were MA. The MAs had a higher prevalence of SDB (68.5%) than NHWs (49.5%) in unadjusted (PR = 1.38; 95% confidence interval (CI): 1.14-1.67) and adjusted analyses (PR = 1.21; 95% CI: 1.01-1.46). The median AHI was 16 (IQR: 7-31) in MAs and nine (IQR: 5-24) in NHWs. The severity of SDB (rate of apneas/hypopneas) was higher in MAs than NHWs in unadjusted (RR = 1.31; 95% CI: 1.09-1.58) but not adjusted analysis (RR = 1.14; 95% CI: 0.95-1.38). There was no ethnic difference in severity among subjects with SDB. CONCLUSION: More than two-thirds of MA stroke patients had SDB, which was almost 40% more common among MAs than NHWs. Physicians treating MA patients after stroke should have a high index of suspicion for SDB, a treatable condition that could otherwise have adverse impact.