Sleep Apnea in TIA/Stroke: Reducing Cardiovascular Risk With Positive Airway Pressure

The homeostasis model assessment-estimated insulin resistance (HOMA-IR). HOMA IR change is one of the measures used to assess cardiovascular risk. HOMA-IR Index (measured by calculating - fasting insulin (microU/L) x fasting glucose (nmol/L)/22.5.). The change from baseline up until the final measurement (up to 12 months) was assessed.

C-reactive protein (CRP) is a blood test marker for inflammation in the body. CRP is produced in the liver and its level is measured by testing the blood. CRP is classified as an acute phase reactant, which means that its levels will rise in response to inflammation. CRP is one of the measures used to assess cardiovascular risk. The change from baseline up until the final measurement (up to 12 months) was assessed.

IL-6 is a type of protein known as a cytokine, produced by cells of the immune system in response to an infection. IL-6 test results measure the amount of IL-6 circulating in the blood and are used as one sign of systemic inflammation. Il-6 is one of the measures used to assess cardiovascular risk. The change from baseline up until the final measurement (up to 12 months) was assessed.

Catecholamine testing measures the amounts of catecholamines which are a group of similar substances/hormones released into the blood in response to physical or emotional stress. The primary catecholamines are dopamine, epinephrine (adrenaline), and norepinephrine. Catecholamine is one of the measures used to assess cardiovascular risk. The change from baseline up until the final measurement (up to 12 months) was assessed.

Heart rate variability (HRV) is the constant variation in milliseconds between heartbeats. HRV is one of the measures used to assess cardiovascular risk. The change from baseline up until the final measurement (up to 12 months) was assessed.

24-H Systolic Blood Pressure is one of the measures used to assess cardiovascular risk- this was assessed multiple times and averaged across a in 24 hour time period. The change from baseline up until the final measurement (up to 12 months) was assessed.

Flow-mediated vasodilation is performed when the brachial artery diameter is measured (in mm) during three conditions; baseline (after at least 10 min supine rest), during reactive hyperaemia (induced by inflation to 250 mmHg and then deflation of a sphygmomanometer cuff around the forearm) and finally after the administration of sublingual nitroglycerin. A linear array, high resolution ultrasound transducer is used to provide B-mode images of the target vessel, proximal to the forearm cuff. Flow-mediated vasodilation is one of the measures used to assess cardiovascular risk and the mean of the change in the multiple measurements was used at each time point. The change from baseline up until the final measurement (up to 12 months) was assessed.

Carotid Intima-Medial Thickness are measurements of the mean values of Intima-media thickness (IMT) of carotid arteries. Caroid Intima-Medial Thickness mean change is one of the measures used to assess cardiovascular risk. The change from baseline up until the final measurement (up to 12 months) was assessed.

CPAP adherence rates were calculated as hours of CPAP use per night. The change from baseline up until the final measurement (up to 12 months) was assessed. The Respironics M-series (now System One, Phillips Respironics, North Ryde, Australia) produced a record of the patient adherence (hours of use per night) throughout the duration of the follow up period.

The homeostasis model assessment-estimated insulin resistance (HOMA-IR). HOMA IR change is one of the measures used to assess cardiovascular risk. HOMA-IR Index (measured by calculating - fasting insulin (microU/L) x fasting glucose (nmol/L)/22.5.) To determine if CPAP use had an impact on cardiovascular risk, these measures were compared among CPAP usage groups. The change from baseline up until the final measurement (up to 12 months) was assessed.

C-reactive protein (CRP) is a blood test marker for inflammation in the body. CRP is produced in the liver and its level is measured by testing the blood. CRP is classified as an acute phase reactant, which means that its levels will rise in response to inflammation. CRP is one of the measures used to assess cardiovascular risk. To determine if CPAP use had an impact on cardiovascular risk, these measures were compared among CPAP usage groups. The change from baseline up until the final measurement (up to 12 months) was assessed.

IL-6 is a type of protein known as a cytokine, produced by cells of the immune system in response to an infection. IL-6 test results measure the amount of IL-6 circulating in the blood and are used as one sign of systemic inflammation. IL-6 is one of the measures used to assess cardiovascular risk. To determine if CPAP use had an impact on cardiovascular risk, these measures were compared among CPAP usage groups. The change from baseline up until the final measurement (up to 12 months) was assessed.

Catecholamine testing measures the amounts of catecholamines which are a group of similar substances/hormones released into the blood in response to physical or emotional stress. The primary catecholamines are dopamine, epinephrine (adrenaline), and norepinephrine. Catecholamines change is one of the measures used to assess cardiovascular risk. To determine if CPAP use had an impact on cardiovascular risk, these measures were compared among CPAP usage groups. The change from baseline up until the final measurement (up to 12 months) was assessed.

Heart rate variability (HRV) is the constant variation in milliseconds between heartbeats. HRV is one of the measures used to assess cardiovascular risk. To determine if CPAP use had an impact on cardiovascular risk, these measures were compared among CPAP usage groups. The change from baseline up until the final measurement (up to 12 months) was assessed.

24-H Mean Systolic Blood Pressure change is one of the measures used to assess cardiovascular risk- this was assessed multiple times and averaged across a in 24 hour time period. To determine if CPAP use had an impact on cardiovascular risk, these measures were compared among CPAP usage groups. The change from baseline up until the final measurement (up to 12 months) was assessed.

Flow-mediated vasodilation is performed when the brachial artery diameter is measured (in mm) during three conditions; baseline (after at least 10 min supine rest), during reactive hyperaemia (induced by inflation to 250 mmHg and then deflation of a sphygmomanometer cuff around the forearm) and finally after the administration of sublingual nitroglycerin. A linear array, high resolution ultrasound transducer is used to provide B-mode images of the target vessel, proximal to the forearm cuff. Flow-mediated vasodilation is one of the measures used to assess cardiovascular risk and the mean of the change in the multiple measurements was used at each time point. To determine if CPAP use had an impact on cardiovascular risk, these measures were compared among CPAP usage groups. The change from baseline up until the final measurement (up to 12 months) was assessed.

Carotid Intima-Medial Thickness are measurements of the mean values of Intima-media thickness (IMT) of carotid arteries. Caroid Intima-Medial Thickness change is one of the measures used to assess cardiovascular risk. To determine if CPAP use had an impact on cardiovascular risk, these measures were compared among CPAP usage groups. The change from baseline up until the final measurement (up to 12 months) was assessed. The carotid intimal thickness measurement was obtained by averaging the distance between the lumen-intima interface and the media-adventitia interface obtained from 5 contiguous sites 1 mm apart.

Change in medication-adjusted 24-hour SBP, which is calculated as [mean 24-hour SBP in mmHg] + [patient's DDD × (8.0 mmHg), was assessed between CPAP adherence groups. The change from baseline up until the final measurement (up to 12 months) was assessed.