Assessing the Symptoms of Obstructive Sleep Apnea

Study Overview
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Brief Summary
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The purpose of this study is to investigate the correlation between health outcomes associated with the severity of obstructive sleep apnea (OSA) symptomatology, the findings will guide the design of interventional studies.

Detailed Description
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Obstructive sleep apnea is a condition characterised by periods of narrowing of the pharyngeal airways during sleep causing hypoxic and hypercapnic episodes with the cessation of ventilation. Considering the high number of overweight and obese individuals in Western society the understanding of the pathomechanisms behind OSA are important. This observational study aims to investigate the correlations between the severity of Obstructive Sleep Apnea assessed by the apnea-hypopnea index (AHI) and different health outcomes associated with the OSA.

Official Title
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Association of Health Outcomes With Severity of OSA Symptomatology- a Correlation Study.

Conditions
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Obstructive Sleep Apnea

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Body Mass Index ≤39 Not received any treatment for Obstructive Sleep Apnea. Is a non-smoker Is not epileptic Epworth Sleepiness Scale ≥ 10. Patient's on Statins or antihypertensive drugs are included as so frequent in OSA. Exclusion Criteria: Body Mass Index ≥ 39. Presence of significant or unstable Renal, Liver or Heart Failure. Receiving anti-diabetic treatment. Is a smoker. Is epileptic Presence of significant or unstable psychological morbidities.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 70 Years

Sexes Eligible for Study
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Male

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| No treatment, OSA (AHI >15)<br>Patients with OSA recruited prior to receiving NHS treatment. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Apnea-Hypopnea Index (AHI) | AHI refers to how is the number of apneas and hypopneas per an hour of sleep. | one night within four weeks of study. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Residual volume | Volume of air remaining in lungs after full expiration | Within four weeks of recruitment prior to CPAP treatment | 
| Functional residual volume | Air present in lungs at the end of passive expiration | Within four weeks of recruitment prior to CPAP treatment | 
| Total lung capacity | Total volume of lungs | Within four weeks of recruitment prior to CPAP treatment | 
| Forced Vital capacity | Maximum amount of air which can be expired from the lungs following a full inspiration | Within four weeks of recruitment prior to CPAP treatment | 
| Forced expiratory volume in one second (FEV1) | Maximum amount of air which can be expired from the lungs in one second. | Within four weeks of recruitment prior to CPAP treatment | 
| Airway Resistance | Opposition of flow caused by forces of friction. | Within four weeks of recruitment prior to CPAP treatment | 
| Plasma 2-arachidonoylglycerol (2-AG) | Ligand of the G-protein coupled CB1 and CB2 receptors, has been found to be correlated with Oleylethanolamide (OEA) in OSA patients have various effects on energy metabolism. | Within four weeks of recruitment prior to CPAP treatment and after four weeks of CPAP treatment. | 
| Plasma Anandamide (ANA) | Ligand of the G-protein coupled CB1 and CB2 receptors, found to be correlated with blood pressure in OSA after the adjustment of confounding variables. Have various effects on energy metabolism. | Within four weeks of recruitment prior to CPAP treatment and after four weeks of CPAP treatment | 
| Plasma oleoylethanolamine (OEA) | A lipid mediator which acts as an anorexigenic (appetite suppressant), and is elevated with sleep deprivation. | Within four weeks of recruitment prior to CPAP treatment and after four weeks of CPAP treatment | 
| Plasma Leptin | Circulating protein produced in adipose tissue. Elevated in OSA and obesity. Leptin may reduce respiratory depression. | Within four weeks of recruitment prior to CPAP treatment and after four weeks of CPAP treatment | 
| Plasma Adiponectin | Hormone secreted by adipocytes (Fat cells). Adiponectin is closely linked to metabolism and may have anti-inflammatory properties. | Within four weeks of recruitment prior to CPAP treatment and after four weeks of CPAP treatment | 
| Plasma C-reactive Protein | Marker of inflammation. | Within four weeks of recruitment prior to CPAP treatment and after four weeks of CPAP treatment | 
| Insulin | Hormone which causes liver and muscle and fat cells to take up glucose to convert to glycogen. OSA is associated with insulin resistance. | Within four weeks of recruitment prior to CPAP treatment and after four weeks of CPAP treatment | 
| Neck circumference |  | Within four weeks of recruitment prior to CPAP treatment | 
| Waist circumference |  | Within four weeks of recruitment prior to CPAP treatment | 
| Hip circumference |  | Within four weeks of recruitment prior to CPAP treatment | 
| Weight |  | Within four weeks of recruitment prior to CPAP treatment | 
| Fat-free mass | Non-fat components of the human body estimated non-invasively using a bioimpedance measurement system. | Within four weeks of recruitment prior to CPAP treatment | 
| Fat mass | Fat components of the human body estimated non-invasively using bioimpedance measurement system. | Within four weeks of recruitment prior to CPAP treatment | 
| Maximal Inspiratory pressure | Measured at residual volume, reflects the strength of the diaphragm and other inspiratory muscles. | Within four weeks of recruitment prior to CPAP treatment | 
| Rate of inspiratory muscle fatigue | The decline in maximal inspiratory pressure following inspiration against a resistance. | Within four weeks of recruitment prior to CPAP treatment | 
| Chest RPE | Rating of perceived exertion in the chest and associated airways during the inspiratory fatigue protocol. | Within four weeks of recruitment prior to CPAP treatment | 
| Dyspnea | Rating of breathlessness half way through fatigue protocol and at the end of protocol. | Within four weeks of recruitment prior to CPAP treatment | 
| Ventilation with 25% O2/ 6% CO2 | Measures the breathing response to high oxygen and high CO2 therefore assessing the central chemoreceptors response only. | Within four weeks of recruitment prior to CPAP treatment | 
| Ventilation with 13% O2 | Measures the breathing response to low oxygen. Designed to Assess the response to the peripheral chemoreceptors. | Within four weeks of recruitment prior to CPAP treatment | 
| Ventilation with 13% O2 / 6% CO2 | Measures the breathing response to low oxygen and high CO2. Designed to assess the response of the sum of the peripheral and central chemoreceptors | Within four weeks of recruitment prior to CPAP treatment | 
| Mean RR interval | Time domain measure: Average time interval between the heart beats R waves | Within four weeks of recruitment prior to CPAP treatment | 
| SDNN | Time domain measure: The standard deviation of all RR intervals | Within four weeks of recruitment prior to CPAP treatment | 
| NN50 count | Time domain measure: The number of pairs of adjacent RR intervals differing by more than 50 ms in the entire analysis interval. | Within four weeks of recruitment prior to CPAP treatment | 
| NN50 of total HR (%) | Time domain measure: NN50 count divided by total number of all RR intervals. | Within four weeks of recruitment prior to CPAP treatment | 
| HRV triangular index | The total number of RR intervals divided by maximum height of the histogram excluding boundaries. | Within four weeks of recruitment prior to CPAP treatment | 
| Low frequency domain | Frequency domain analysis: represents 0.04-0.15 Hz reflecting sympathetic activity. | Within four weeks of recruitment prior to CPAP treatment. | 
| High frequency domain | Frequency domain analysis: represents 0.15-0.40 Hz reflecting parasympathetic activity. | Within four weeks of recruitment prior to CPAP treatment. | 
| LF/HF ratio | The ratio of low frequency (0.04 - 0.15 Hz) to high (0.15-0.40 Hz) frequency recordings. | Within four weeks of recruitment prior to CPAP treatment. | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Obstructive sleep apnea, correlation, AHI, symptoms, mechanisms