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Effect of Continuous Positive Airway Pressure for Treatment of Obstructive Sleep Apnea on Resistant Hypertension

This study is currently recruiting participants. (see Contacts and Locations)
Verified January 2016 by The University of Hong Kong
Information provided by:
The University of Hong Kong Identifier:
First received: April 14, 2009
Last updated: January 17, 2016
Last verified: January 2016
The objectives of this study are to investigate the effect of continuous positive airway pressure (CPAP) treatment on blood pressure control and vascular inflammation in subjects with resistant hypertension and moderate obstructive sleep apnea (OSA).

Condition Intervention
Resistant Hypertension
Obstructive Sleep Apnea
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: Effect of Continuous Positive Airway Pressure for Treatment of Obstructive Sleep Apnea on Drug-resistant Hypertension : A Randomized Controlled Trial

Resource links provided by NLM:

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

Primary Outcome Measures:
  • mean systolic blood pressure [ Time Frame: 8 weeks ] [ Designated as safety issue: No ]

Secondary Outcome Measures:
  • mean arterial blood pressure [ Time Frame: 8 weeks ] [ Designated as safety issue: No ]
  • mean diastolic blood pressure [ Time Frame: 8 weeks ] [ Designated as safety issue: No ]
  • high sensitivity C-reactive protein [ Time Frame: 8 weeks ] [ Designated as safety issue: No ]

Estimated Enrollment: 64
Study Start Date: March 2009
Estimated Primary Completion Date: December 2016 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: continuous positive airway pressure Device: continuous positive airway pressure
Use CPAP whenever sleep
Other Name: CPAP
No Intervention: observation

Detailed Description:
Resistant hypertension is defined as blood pressure that remains above goal in spite of concurrent use of 3 antihypertensive agents of different classes. Resistant hypertension is defined in order to identify patients who are at risk of having secondary causes of hypertension, and who may benefit from specific diagnostic and therapeutic applications. Despite the fact that OSA is listed as one of the causes of resistant HT , paucity of works has demonstrated the magnitude of problems of untreated OSA in subjects with resistant HT. There is so far two study demonstrating the beneficial effect of CPAP treatment in subjects with resistant HT, though both studies were flawed by not including the control group, no randomization and limited sample size. We aim at conducting a randomized controlled study to explore the beneficial effect of CPAP treatment in subjects with OSA and resistant hypertension.

Ages Eligible for Study:   18 Years to 65 Years   (Adult)
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Age 18 - 65
  • known hypertension on ≧ 3 anti-hypertensive drugs
  • Apnea-hypopnea index ≧15
  • able to give informed written consent

Exclusion Criteria:

  • moderate renal impairment (glomerular filtration rate <30 mL/min/m2 )
  • endocrine/renal/cardiac causes of secondary HT
  • congestive heart failure and clinically fluid overloaded
  • On drugs that elevates BP e.g. NSAID, steroid
  • Non-compliance to anti-hypertensive medications
  • Unstable medical conditions such as unstable angina, recent myocardial infarction/stroke within 3 months
  • Active inflammatory/infective conditions e.g. rheumatoid arthritis
  • Excessive sleepiness that can be risky e.g. occupational driver, machine operator
  • Modification/changes of anti-hypertensive regimen within 8 weeks
  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: NCT00881985

Contact: Mary SM Ip, MD 852-28554455
Contact: Macy MS Lui, MRCP 852-28553312

Queen Mary Hospital Recruiting
Hong Kong, China, 852
Contact: Mary SM Ip, MD    852-28554455   
Sponsors and Collaborators
The University of Hong Kong
Principal Investigator: Mary SM Ip, MD The University of Hong Kong
  More Information


Responsible Party: Professor Ip Sau Man Mary, The University of Hong Kong Identifier: NCT00881985     History of Changes
Other Study ID Numbers: UW 09-051 
Study First Received: April 14, 2009
Last Updated: January 17, 2016
Health Authority: Hong Kong: Institutional Review Board

Keywords provided by The University of Hong Kong:
obstructive sleep apnea
resistant hypertension
refractory hypertension
continuous positive airway pressure
blood pressure control

Additional relevant MeSH terms:
Sleep Apnea Syndromes
Sleep Apnea, Obstructive
Vascular Diseases
Cardiovascular Diseases
Respiration Disorders
Respiratory Tract Diseases
Signs and Symptoms, Respiratory
Signs and Symptoms
Sleep Disorders, Intrinsic
Sleep Wake Disorders
Nervous System Diseases processed this record on October 21, 2016