Assessing the Symptoms of Obstructive Sleep Apnea (OSA)

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

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.

Study Overview

• Status: Completed
• Conditions: Obstructive Sleep Apnea

Detailed Description

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.

• Study Type: Observational
• Enrollment (Actual): 66

Contacts and Locations

Study Locations

• United Kingdom
  • Gwynedd
    • Bangor, Gwynedd, United Kingdom, LL57 2PW
      • Betsi Cadwaladr University Health Board

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 70 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: Male

• Sampling Method: Non-Probability Sample

Study Population

Mild to severe recently diagnosed Obstructive Sleep Apnea patients selected by physician who have not received any treatment for their condition. Selected from Ysbyty Gwynedd in North Wales.

Description

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.

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort
No treatment, OSA (AHI >15); Patients with OSA recruited prior to receiving NHS treatment.

What is the study measuring?

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.

Collaborators and Investigators

• Sponsor: Bangor University
• Investigators: Principal Investigator: Christopher MN Earing, MSc, School of Sport, Health and Exercise Sciences, Bangor University

Study record dates

Study Major Dates

• Study Start: November 1, 2011
• Primary Completion (Actual): June 1, 2014
• Study Completion (Actual): June 1, 2014

Study Registration Dates

• First Submitted: November 24, 2011
• First Submitted That Met QC Criteria: November 24, 2011
• First Posted (Estimate): November 29, 2011

Study Record Updates

• Last Update Posted (Estimate): June 17, 2014
• Last Update Submitted That Met QC Criteria: June 16, 2014
• Last Verified: June 1, 2014

More Information

Terms related to this study

• Keywords: Obstructive sleep apnea; symptoms; AHI; correlation; mechanisms
• Additional Relevant MeSH Terms: Nervous System Diseases; Respiratory Tract Diseases; Respiration Disorders; Sleep Disorders, Intrinsic; Dyssomnias; Sleep Wake Disorders; Signs and Symptoms, Respiratory; Sleep Apnea Syndromes; Sleep Apnea, Obstructive; Apnea
• Other Study ID Numbers: REC No: 11/WNo:01/2; Earing 11/WNo01/2 (Other Identifier: North West Wales Research Ethics Committee)