Exploring the Role of Adipocyte Fatty Acid Binding Protein in the Association of Obstructive Sleep Apnea and Metabolic Dysfunction

This study is currently recruiting participants. (see Contacts and Locations)
Verified April 2016 by The University of Hong Kong
Information provided by:
The University of Hong Kong
ClinicalTrials.gov Identifier:
First received: July 29, 2010
Last updated: April 15, 2016
Last verified: April 2016
Adipocyte fatty acid binding protein (A-FABP) is a member of the FABP super family, is abundant in adipocytes and macrophages. Regulatory functions of A-FABP in lipid and glucose metabolism have been described, and it is suggested to play an important role in the pathogenesis of metabolic syndrome.We hypothesize that obstructive sleep apnea (OSA) may upregulate A-FABP production and thus causally contribute to metabolic dysfunction. Our group has recently demonstrated that A-FABP, expressed and secreted from adipocytes, is present in the blood stream .The levels of A-FABP correlated with various metabolic variates in the metabolic syndrome. Furthermore, we have obtained novel data in men with a range of sleep disordered breathing showed that the duration of oxygen desaturation correlated with circulating levels of A-FABP, independent of age and waist/body mass index. The current proposal aims to pursue this finding and further explore the role of A-FABP in the association of OSA and metabolic dysfunction.

Condition Intervention
Obstructive Sleep Apnea
Insulin Resistance
Metabolic Syndrome
Device: continuous positive airway pressure

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Treatment
Official Title: Randomized Controlled Trial of the Effect of Continuous Positive Airway Pressure on Adipocyte Fatty Acid Binding Protein and Other Metabolic Markers in Obstructive Sleep Apnea

Resource links provided by NLM:

Further study details as provided by The University of Hong Kong:

Primary Outcome Measures:
  • adipocyte fatty acid binding protein [ Time Frame: changes over 4 weeks of CPAP treatment ] [ Designated as safety issue: No ]
    This will be done with human A-FABP ELISA reagent set (Biovendor Laboratory Medicine Inc., Czech Republic)

Secondary Outcome Measures:
  • serum Insulin and glucose [ Time Frame: changes over 4 weeks of CPAP treatment ] [ Designated as safety issue: No ]
    Serum insulin will be determined with microparticle enzyme immunoassay on Abbott IMx system (Abbott, Abbott Park, IL). Plasma glucose will be measured by the glucose oxidase method on a Beckman autoanalyzer (Beckman Instruments, Bream, CA). The estimation of insulin resistance by the homeostasis model assessment method (HOMA-IR) will be calculated

  • Lipids and lipoprotein [ Time Frame: changes over 4 weeks of CPAP treatment ] [ Designated as safety issue: No ]
    Plasma total cholesterol and triglyceride will be determined enzymatically on Hitachi 912 analyzer .

  • serum Non-esterified fatty acids [ Time Frame: changes over 4 weeks of CPAP treatment ] [ Designated as safety issue: No ]
    measurement of total plasma free fatty acids using enzyme-coupled colorimetric assay

  • serum Total plasma 8-isoprostane [ Time Frame: changes over 4 weeks of CPAP treatment ] [ Designated as safety issue: No ]
    measured by a specific enzyme immunoassay kit

  • serum inflammatory markers [ Time Frame: changes over 4 weeks of CPAP treatment ] [ Designated as safety issue: No ]

Estimated Enrollment: 90
Study Start Date: June 2008
Estimated Study Completion Date: December 2016
Estimated Primary Completion Date: June 2016 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: continuous positive airway pressure
using continuous positive airway pressure (CPAP) device during sleep, for the study period (4 weeks)
Device: continuous positive airway pressure
an device to be used during sleep, which was a nasal mask connected to a device with pressure applied to upper airway
No Intervention: control
observation for the study period (4 weeks, no CPAP)

Detailed Description:

We hypothesize that there are changes in circulating A-FABP level which can be mitigated by effective treatment of OSA.

The aim is to investigate the effect of CPAP treatment of OSA on circulating A-FABP, and the relationship of changes in serum A-FABP with changes in oxidative stress, inflammation and metabolic variates.


Ages Eligible for Study:   18 Years to 65 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Subjects between 18 - 65 years old
  • Able to understand and give informed written consent

Exclusion Criteria:

  • BMI > 35 kg/m2
  • known diabetes mellitus or hyperlipidemia on treatment
  • known cardiovascular disease except hypertension stable on treatment
  • unstable medical illness
  • need for starting treatment for OSA or other medical conditions immediately
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT01173432

Contact: Macy MS Lui, MRCP 22554455 ext 852 macylui@graduate.hku.hk
Contact: Mary SM Ip, MD 22554455 ext 852 msmip@hkucc.hku.hk

Hong Kong
The University of Hong Kong Recruiting
Hong Kong, Hong Kong, 852
Contact: Macy MS Lui, MRCP    22554455 ext 852    macylui@graduate.hku.hk   
Sub-Investigator: David CL Lam, PhD         
Sub-Investigator: Macy MS Lui, MRCP         
Sponsors and Collaborators
The University of Hong Kong
Principal Investigator: Mary SM Ip, MD The University of Hong Kong, Queen Mary Hospital
  More Information

Responsible Party: Professor Mary SM Ip, The University of Hong Kong, Queen Mary Hospital
ClinicalTrials.gov Identifier: NCT01173432     History of Changes
Other Study ID Numbers: UW07-178  HKCTR-770 
Study First Received: July 29, 2010
Last Updated: April 15, 2016
Health Authority: Hong Kong: Ethics Committee

Keywords provided by The University of Hong Kong:
obstructive sleep apnea
metabolic dysfunction
metabolic syndrome
adipocyte fatty acid binding protein

Additional relevant MeSH terms:
Insulin Resistance
Metabolic Syndrome X
Sleep Apnea Syndromes
Sleep Apnea, Obstructive
Glucose Metabolism Disorders
Metabolic Diseases
Nervous System Diseases
Pathologic Processes
Respiration Disorders
Respiratory Tract Diseases
Signs and Symptoms
Signs and Symptoms, Respiratory
Sleep Disorders
Sleep Disorders, Intrinsic

ClinicalTrials.gov processed this record on April 27, 2016