The Influence of Mandibular Advancement Device Treating OSAHS on Primary Prevention of Ischemic Stroke

Study Overview
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Brief Summary
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The purpose of this study is to detect the differences of carotid atherosclerosis severity between patients with or without OSAHS(Obstructive Sleep Apnea and Hypopnea Syndrome) in a cross-sectional study in a large sample. Then a longitudinal control study is conducted to observe the progress of the carotid atherosclerosis by vascular ultrasonography and the occurrence of cerebrovascular events after the intervention of the oral appliance for treating OSAHS，and finally explore the feasibility of using oral appliance to treat OSAHS in primary prevention of ischemic stroke.

Detailed Description
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the relevance of OSAHS and carotid atherosclerosis Patients are distributed questionnaire and recruited from neurology clinic，vascular ultrasonography clinic of Xuanwu Hospital if they match the inclusion criteria. After initial screening, carotid atherosclerosis patients with skeptical OSAHS are sent to sleep center for polysomnography examination to determine the severity of OSAHS. At least 50 patients for mild, moderate, severe OSAHS each are recruited for OSAHS Group. At least 100 patients without snoring from questionnaire and without OSAHS after PSG screening are recruited for non OSAHS Group. Vascular ultrasonography examination for carotid are done for the two groups. Data of carotid vascular plaque from two groups are collected. Statistics are done to detect differences of carotid atherosclerosis severity between patients with and without OSAHS, also the severity of OSAHS. the relevance of the progress of carotid atherosclerosis and oral appliances intervention for treating OSAHS All carotid atherosclerosis patients with OSAHS are from patients of the first study. If they consent the treatment of oral appliances, they are recruited into this second study. At least 100 patients are recruited. They are divided into 2 groups by randomized block design by Evidence-based Medicine Center of Xuanwu Hospital. One group is oral appliance intervention group, the other group is no intervention group. The intervention group patients accept oral appliance treatment, and no intervention group patients do not accept OSAHS treatment. The two groups both accept anti-hypertension treatment or anti-diabetes treatment, or anti-hyperlipidemia treatment according to their own situation in neurology clinic. At timepoint of initial time, one month after oral appliance treatment, one and a half year after oral appliance treatment, the intervention group should accept PSG(Polysomnography) examination to monitor the treatment of OSAHS. At timepoint of initial time, one month after oral appliance treatment, one and a half year after oral appliance treatment, the two groups should accept breath holding test to monitor the cerebral vascular reserve. At timepoint of initial time, one and a half year after oral appliance treatment, the two groups should accept carotid vascular ultrasonography examination to monitor the progress of carotid atherosclerosis. Cerebrovascular events and death are recorded from initial time. Statistics are done to detect the influence of treatment of OSAHS on carotid atherosclerosis.

Official Title
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The Influence of Mandibular Advancement Device Treating OSAHS on Primary Prevention of Ischemic Stroke

Conditions
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Sleep Apnea Syndromes, Atherosclerosis, Carotid Plaque

Intervention / Treatment
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* Device: oral appliance treatment


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: diagnosed with atherosclerosis by vascular ultrasonography diagnosed with OSAHS by polysomnography Exclusion Criteria: patients who have stroke already patients who can not wear oral appliances according to experiment requirements patients who have bad periodontal condition or teeth number less than 20
Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Oral appliance intervention<br> | Device: oral appliance treatment<br>* mandibular advancement device to enlarge pharyngeal airway space to get rid of apnea and hypopnea events<br>|
| No Intervention: Without oral appliance intervention<br> | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| apnea hypopnea events 0 in Times | apnea and hypopnea times per hour | initial time when patients are recruited | 
| apnea hypopnea events 1 in Times | apnea and hypopnea times per hour | one month after oral appliance treatment | 
| apnea hypopnea events 2 in Times | apnea and hypopnea times per hour | one and a half years after oral appliance treatment | 
| longest apnea time 0 in Seconds | longest apnea or hypopnea time | initial time when patients are recruited | 
| longest apnea time 1 in Seconds | longest apnea or hypopnea time | one month after oral appliance treatment | 
| longest apnea time 2 in Seconds | longest apnea or hypopnea time | one and a half years after oral appliance treatment | 
| Blood oxygen saturation less than 90% of the total monitoring time percentage 0 in percentage | Blood oxygen saturation less than 90% of the total monitoring time percentage | initial time when patients are recruited | 
| Blood oxygen saturation less than 90% of the total monitoring time percentage 1 in percentage | Blood oxygen saturation less than 90% of the total monitoring time percentage | one month after oral appliance treatment | 
| Blood oxygen saturation less than 90% of the total monitoring time percentage 2 in percentage | Blood oxygen saturation less than 90% of the total monitoring time percentage | one and a half years after oral appliance treatment | 
| lowest Oxygen Saturation 0 in percentage | blood lowest oxygen saturation during the whole night | initial time when patients are recruited | 
| lowest Oxygen Saturation 1 in percentage | blood lowest oxygen saturation during the whole night | one month after oral appliance treatment | 
| lowest Oxygen Saturation 2 in percentage | blood lowest oxygen saturation during the whole night | one and a half years after oral appliance treatment | 
| atherosclerosis plaque thickness 0 in common carotid artery in milimetre | atherosclerosis plaque thickness is distance from the most convex point of plaque to carotid media | initial time when patients are recruited | 
| atherosclerosis plaque thickness 1 in common carotid artery in milimetre | atherosclerosis plaque thickness is distance from the most convex point of plaque to carotid media | one and a half years after oral appliance treatment | 
| atherosclerosis plaque length 0 in common carotid artery in milimetre | atherosclerosis plaque length is distance from the beginning to the end of a separate plaque | initial time when patients are recruited | 
| atherosclerosis plaque length 1 in common carotid artery in milimetre | atherosclerosis plaque length is distance from the beginning to the end of a separate plaqu | one and a half years after oral appliance treatment | 
| atherosclerosis plaque thickness 0 in internal carotid artery in milimetre | atherosclerosis plaque thickness is distance from the most convex point of plaque to carotid media | initial time when patients are recruited | 
| atherosclerosis plaque thickness 1 in internal carotid artery in milimetre | atherosclerosis plaque thickness is distance from the most convex point of plaque to carotid media | one and a half years after oral appliance treatment | 
| atherosclerosis plaque thickness 0 in carotid bulb in milimetre | atherosclerosis plaque thickness is distance from the most convex point of plaque to carotid media | initial time when patients are recruited | 
| atherosclerosis plaque thickness 1 in carotid bulb in milimetre | atherosclerosis plaque thickness is distance from the most convex point of plaque to carotid media | one and a half years after oral appliance treatment | 
| atherosclerosis plaque length 0 in internal carotid artery in milimetre | atherosclerosis plaque length is distance from the beginning to the end of a separate plaque | initial time when patients are recruited | 
| atherosclerosis plaque length 1 in internal carotid artery in milimetre | atherosclerosis plaque length is distance from the beginning to the end of a separate plaque | one and a half years after oral appliance treatment | 
| atherosclerosis plaque length 0 in carotid bolb in milimetre | atherosclerosis plaque length is distance from the beginning to the end of a separate plaque | initial time when patients are recruited | 
| atherosclerosis plaque length 1 in carotid bolb in milimetre | atherosclerosis plaque length is distance from the beginning to the end of a separate plaque | one and a half years after oral appliance treatment | 
| breath holding index 0 in percentage/seconds | breath holding index = (v2-v1)/v2*100/t. v2 is average velocity of middle cerebral artery after breath holding, v1 is average velocity of middle cerebral artery before breath holding, t is time for breath holding. | initial time when patients are recruited | 
| breath holding index 0 in percentage/seconds | breath holding index = (v2-v1)/v2*100/t. v2 is average velocity of middle cerebral artery after breath holding, v1 is average velocity of middle cerebral artery before breath holding, t is time for breath holding. | one and a half years after oral appliance treatment | 
| End systolic velocity of common carotid artery 0 in cm/s | the velocity of common carotid artery at the end of systolic period | initial time when patients are recruited | 
| End systolic velocity of common carotid artery 1 in cm/s | the velocity of common carotid artery at the end of systolic period | one and a half years after oral appliance treatment | 
| End systolic velocity of internal carotid artery 0 in cm/s | the velocity of internal carotid artery at the end of systolic period | initial time when patients are recruited | 
| End systolic velocity of internal carotid artery 1 in cm/s | the velocity of internal carotid artery at the end of systolic period | one and a half years after oral appliance treatment | 
| End systolic velocity of carotid bulb 0 in cm/s | the velocity of carotid bulb at the end of systolic period | initial time when patients are recruited | 
| End systolic velocity of carotid bulb 1 in cm/s | the velocity of carotid bulb at the end of systolic period | one and a half years after oral appliance treatment | 
| end diastolic velocity of common carotid artery 0 in cm/s | the velocity of common carotid artery at the end of diastolic period | initial time when patients are recruited | 
| end diastolic velocity of common carotid artery 1 in cm/s | the velocity of common carotid artery at the end of diastolic period | one and a half years after oral appliance treatment | 
| end diastolic velocity of internal carotid artery 0 in cm/s | the velocity of internal carotid artery at the end of diastolic period | initial time when patients are recruited | 
| end diastolic velocity of internal carotid artery 1 in cm/s | the velocity of internal carotid artery at the end of diastolic period | one and a half years after oral appliance treatment | 
| end diastolic velocity of carotid bulb 0 in cm/s | the velocity of carotid bulb at the end of diastolic period | initial time when patients are recruited | 
| end diastolic velocity of carotid bulb 1 in cm/s | the velocity of carotid bulb at the end of diastolic period | one and a half years after oral appliance treatment |