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Hypoxia Inducible factor1-Alpha Genetic Polymorphism of Obstructive Sleep Apnea

The recruitment status of this study is unknown. The completion date has passed and the status has not been verified in more than two years.
Verified January 2009 by National Taiwan University Hospital.
Recruitment status was:  Recruiting
Information provided by:
National Taiwan University Hospital Identifier:
First received: July 8, 2007
Last updated: January 12, 2009
Last verified: January 2009

Specific Aim

  1. To identify specific SNPs of HIF-1 gene related to cardiovascular disease in OSA patients (CVD-OSA)
  2. To assay the functional activity of high risk SNPs of HIF-1 on the transcription of VEGF gene
  3. To confirm that the serum level of VEGF in CVD-OSA patients with high risk SNPs of HIF-1 are higher than CVD-OSA patients without

Sleep Apnea, Obstructive

Study Type: Observational
Study Design: Observational Model: Case Control
Time Perspective: Prospective

Resource links provided by NLM:

Further study details as provided by National Taiwan University Hospital:

Estimated Enrollment: 1000
Study Start Date: March 2006
Detailed Description:

Obstructive sleep apnea syndrome(OSAS) is characterized with recurrent collapse of upper airway during sleep and results in hypoxia and sleep fragmentation. The repeated episodes of hypoxia and sympathetic hyperactivity result in cardiovascular complications, including atherosclerosis, hypertension, coronary artery disease and heart failure. Our data showed among 309 consecutively-admitted OSA patients, 54% patients had cardiovascular diseases.

The hypoxia in OSA is characterized as chronic and intermittent, which leads to sophisticated adaptive mechanisms, like activations of transcriptional factors and critical signaling pathways. HIF-1 is a central component of transcriptional factors involved in hypoxia-induced transcription of specific genes. There are two subunits of HIF-1 transcription factor, which interact with the consensus hypoxia response element in the target genes. The HIF-1 alpha activity is regulated by proline hydroxylation modification and ubiquitination, which is oxygen-tension dependent. HIF-1 alpha target genes encode proteins that increase oxygen delivery, such as vascular endothelial growth factor(VEGF). Our oligo-microarray study showed both HIF and VEGF expression in OSA patients was 1.3 times of control group, which decreased to 46% and 57% respectively after one-month CPAP treatment.

HIF-1 alpha polymorphism could result in increased HIF-1 alpha activity and microvessel density. In clinical observation, HIF-1 polymorphism has been reported to be associated with high altitude adaptation, formation of coronary collaterals in CAD and phenotype of cancer. These findings were possibly explained with effect of HIF on modulation of VEGF.

Several genetic polymorphisms were reported to be associated with OSA, which included TNF alpha, angiotensin converting enzyme and haptoglobin. Only hepatoglobin phenotype is proved to be a risk factor for cardiovascular disease in OSA. In most studies, the patient number is less than suggested.

Therefore, in this study, we hypothesized that HIF-1 gene polymorphism was associated with cardiovascular disease in OSA. And by using large-scale of study population(1000 OSA patients), we examined all regions of the HIF-1 alpha to detect single-nucleotide polymorphisms(SNPs), evaluated the pattern of linkage disequilibrium to compose haplotypes in the gene, and performed association studies in OSA patients with and without cardiovascular disease to achieve the following 3 objectives:(1)To identify specific SNPs of HIF-1 alpha gene related to cardiovascular disease in OSA patients (CVD-OSA).(2)To assay the functional activity of high risk SNPs of HIF-1 alpha on the transcription of VEGF gene.(3)To confirm that the serum level of VEGF in CVD-OSA patients with high risk SNPs of HIF-1 are higher than CVD-OSA patients without. The findings are expected to stratify the risk of OSA patients to specific outcome, or response to specific therapy.


Ages Eligible for Study:   18 Years and older   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Sampling Method:   Probability Sample
Study Population
patients referred sleep center to rule out obstructive sleep apnea

Inclusion Criteria:

  • Severe obstructive sleep apnea (AHI>=30/hr) age, sex, BMI match control subject

Exclusion Criteria:

  • Patients were excluded when: (1) refused to participate in this study, (2) had severe obstructive pulmonary disease or active neurological events, (3) enrolled in other studies at the same time
  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 identifier: NCT00498693

Contact: Peilin Lee, M.D. +886-2-23562905

National Taiwan Univeristy Hospital Recruiting
Taipei, Taiwan
Contact: Peilin Lee, M.D.    +886-2-23562905   
Sub-Investigator: Peilin Lee, M.D.         
Sponsors and Collaborators
National Taiwan University Hospital
Principal Investigator: Hey-Dong Wu, M.D. National Taiwan University Hospital
  More Information

Publications automatically indexed to this study by Identifier (NCT Number):
Responsible Party: Peilin Lee, National Taiwan University Hospital Identifier: NCT00498693     History of Changes
Other Study ID Numbers: 9561701013
Study First Received: July 8, 2007
Last Updated: January 12, 2009

Additional relevant MeSH terms:
Sleep Apnea Syndromes
Sleep Apnea, Obstructive
Respiration Disorders
Respiratory Tract Diseases
Sleep Disorders, Intrinsic
Sleep Wake Disorders
Nervous System Diseases processed this record on August 16, 2017