Sleep Apnea and Periodic Breathing (DLI)

Screening for Sleep Apnea Using Home Recording of the Double Loop Gain as a Measure of Periodic Breathing

The purpose of this study is to determine the double loop index (DLI) threshold with optimal sensitivity and specificity. The investigators hypothesize that the DLI gives a better reflection of the pathophysiology of the disease than the apnea-hypopnea-index (AHI).

Study Overview

• Status: Unknown
• Conditions: Sleep Apnea Syndrome

Detailed Description

Sleep apnea syndrome (SAS) is characterized by repetitive events of apnea and hypopnea. These events are often part of a periodic breathing pattern, in which relative hyperventilation is followed by apnea or hypopnea.

Recently the investigators described the 'double-loop gain' of the respiratory control system as a measure of periodic breathing. This is a frequency-dependent variable which describes 1) the tendency of the respiratory system to oscillate at a given frequency and 2) the degree to which the relation between oscillations in ventilation and oscillations in arterial blood gas values is linear. The underlying hypothesis is that periodic breathing results from negative feedback regulation of arterial O2 and CO2 pressure through the chemoreflexes. The double-loop gain describes the gain in the negative feedback loop under the assumption that accidental changes occur in both ventilation and arterial blood gas pressures. A simple version of the double-loop gain is derived from nasal pressure changes and arterial O2 saturation. From all-night recordings, the 'double-loop index' (DLI) can be derived, which is determined by the time during which the double-loop gain exceeds a given threshold.

Currently, the presence of sleep-apnea is determined by the apnea-hypopnea index (AHI), using in-hospital sleep recording. With a growing number of referrals, waiting lists for sleep registration are emerging. Screening for SAS using home-measurement of nasal pressure and SaO2 seems to be a good alternative. The investigators hypothesize that the DLI derived from these signals gives a better reflection of the pathophysiology of the disease than the AHI. As a result, the investigators expect that the DLI improves the distinction between healthy and diseased subjects in comparison to the simple counting of apneas and hypopneas. This is reflected in a higher area under the ROC curve, which describes the sensitivity and specificity of the test.

• Study Type: Observational
• Enrollment (Anticipated): 50

Contacts and Locations

Study Locations

• Netherlands
  • Wilhelminalaan 12
    • Alkmaar, Wilhelminalaan 12, Netherlands, 1815 JD
      • Recruiting
      • Medical Center Alkmaar
      • Contact: J.G. van den Aardweg, dr.; Phone Number: +3172-5482750; Email: j.g.vanden.aardweg@mca.nl

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Outpatients suspected for sleep apnea syndrome

Description

Inclusion Criteria:

• Suspected sleep apnea syndrome
• > 18 yr
• Outpatient
• Able and willing to use the necessary equipment for registration of nasal pressure and O2 saturation at home

Exclusion Criteria:

• hospitalized patients
• < 18 yr
• Not able to use the necessary equipment

Study Plan

How is the study designed?

Design Details

• Observational Models: Cohort
• Time Perspectives: Cross-Sectional

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort
Suspected sleep apnea syndrome; Outpatients with suspected sleep apnea syndrome, age > 18 year

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
To determine DLI threshold with optimal sensitivity and specificity. The DLI threshold is the DLI value above which the test is considered positive. The optimal DLI threshold will be taken as the value that gives the highest area under the ROC curve.	1 year

Secondary Outcome Measures

Outcome Measure	Time Frame
To test the hypothesis that the sensitivity and specificity of the screening are higher when the DLI is used instead of the AHI	1 year
To assess the repeatability of the DLI using home and in-hospital recordings of nasal pressure and saturation (SaO2).	1 year

Collaborators and Investigators

• Sponsor: Medical Center Alkmaar
• Investigators: Study Director: J.G. van den Aardweg, dr, Medical Center Alkmaar

Study record dates

Study Major Dates

• Study Start: June 1, 2009

Study Registration Dates

• First Submitted: July 9, 2009
• First Submitted That Met QC Criteria: July 9, 2009
• First Posted (Estimate): July 10, 2009

Study Record Updates

• Last Update Posted (Estimate): July 10, 2009
• Last Update Submitted That Met QC Criteria: July 9, 2009
• Last Verified: July 1, 2009

More Information

Terms related to this study

• Keywords: polysomnography; DLI; Sleep apnea syndrome; SAS; double loop gain; double loop index; periodic breathing
• Additional Relevant MeSH Terms: Pathologic Processes; Nervous System Diseases; Respiratory Tract Diseases; Respiration Disorders; Sleep Disorders, Intrinsic; Dyssomnias; Sleep Wake Disorders; Signs and Symptoms, Respiratory; Sleep Apnea Syndromes; Respiratory Aspiration; Apnea
• Other Study ID Numbers: Double loop gain MCA 2009