Effects of Continuous Positive Airway Pressure (CPAP) in Patients With Resistant Hypertension and Obstructive Sleep Apnea (OSA)

This study has been completed.
Sponsor:
Information provided by (Responsible Party):
Geraldo Lorenzi-Filho, University of Sao Paulo
ClinicalTrials.gov Identifier:
NCT00812695
First received: December 19, 2008
Last updated: November 21, 2011
Last verified: November 2011
  Purpose

Obstructive sleep apnea (OSA) is an important cause of refractory hypertension but the impact of treatment with continuous positive airway pressure (CPAP) is not completely understood. The aim of this project is to study the effects of CPAP on blood pressure control and its influences on cardiac remodeling and arterial stiffness in patients with refractory hypertension and moderate or severe OSA.


Condition Intervention Phase
Obstructive Sleep Apnea
Refractory Hypertension
Device: CPAP
Phase 3

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Treatment
Official Title: Effects of Continuous Positive Airway Pressure in Patients With Resistant Hypertension and Obstructive Sleep Apnea

Resource links provided by NLM:


Further study details as provided by University of Sao Paulo:

Primary Outcome Measures:
  • Ambulatory blood pressure monitoring [ Time Frame: Change from Baseline in Blood Pressure at 6 months ] [ Designated as safety issue: Yes ]

Secondary Outcome Measures:
  • Change from Baseline in Arterial stiffness at 6 months [ Time Frame: baseline and 6 months ] [ Designated as safety issue: Yes ]
  • change from baseline in heart remodeling at 6 months [ Time Frame: baseline and 6 months ] [ Designated as safety issue: Yes ]

Enrollment: 40
Study Start Date: October 2008
Study Completion Date: March 2011
Primary Completion Date: March 2011 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
No Intervention: 1
Active Comparator: 2
CPAP
Device: CPAP
Gold standard treatment for Obstructive sleep apnea

Detailed Description:

Study design Interventional, open-label, randomized.

Patients selection

Fifty refractory hypertensive patients with moderate-to-severe OSA, aged between 30 to 65 years old will be recruited from the outpatient clinics of the Heart Institute by the hospital staff.

Refractory hypertension will be defined as usually: blood pressure higher than or equal to 140x90 mmHg after a regimen of three drugs, including a diuretic for a minimum of 3 months. Initial evaluation will consist on ambulatory blood pressure measurement for 24 hours and a detailed clinical examination. Moderate to severe OSA will be defined as an apnea-hypopnea index > 15 evens per hour, after an overnight polysomnography.

Exclusion criteria include BMI >40 kg/m2; diabetes mellitus; aortic, heart and valve diseases; renal failure; other identifiable causes of hypertension, no adherence, use of cocaine, amphetamines, other illicit drugs, sympathomimetics (decongestants, anorectics), oral contraceptive hormones, nonsteroidal anti-inflammatory drugs.

Refractory hypertension Secondary causes of hypertension will be excluded using usual procedures from the Hypertension Unit.

Polysomnography All participants will be submitted to standard overnight polysomnography (EMBLA - Flagra hf. Medical Devices, Reykjavik, Iceland). The apnea-hypopnea index will be calculated as the total number of respiratory events (apneas plus hypopneas) per hour of sleep.

Apnea will be defined as an air flow cessation greater than 10 seconds and hypopnea as a reduction grater than 50% with oxygen saturation fall grater than 4% or arousal.

After recruitment, patients will be instructed about CPAP working by an experimented professional and another polysomnography will be done to adjust pressures. Hour counter will be used to check the adherence to CPAP.

Intervention Patients will be divided in two groups: medical treatment plus CPAP or medical treatment alone for 6 months without drug dose changing.

Twenty-four hour blood pressure monitoring Twenty-four hour blood pressure monitoring (system SpaceLabs 90207) will be used in all patients in the beginning and at the end of the study.

Arterial Stiffness Carotid-femoral arterial stiffness will be determined by Complior.

Echocardiography Echocardiography will be performed by using a commercially available machine.

  Eligibility

Ages Eligible for Study:   30 Years to 65 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  • Refractory hypertensive patients with moderate-to-severe OSA, aged between 30 to 65 years old.

Exclusion Criteria:

  • Aortic, heart and valve diseases
  • Renal failure
  • Other identifiable causes of hypertension, no adherence, use of cocaine, amphetamines, other illicit drugs, sympathomimetics (decongestants, anorectics), oral contraceptive hormones, nonsteroidal anti-inflammatory drugs.
  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: NCT00812695

Locations
Brazil
Heart Institute (InCor)
Sao Paulo, Brazil, 05403-904
Sponsors and Collaborators
University of Sao Paulo
  More Information

No publications provided by University of Sao Paulo

Additional publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
Responsible Party: Geraldo Lorenzi-Filho, MD; PhD, University of Sao Paulo
ClinicalTrials.gov Identifier: NCT00812695     History of Changes
Other Study ID Numbers: RH-OSA
Study First Received: December 19, 2008
Last Updated: November 21, 2011
Health Authority: Brazil: National Committee of Ethics in Research

Keywords provided by University of Sao Paulo:
Obstructive sleep apnea
Refractory hypertension
Heart remodeling
Arterial stiffness
CPAP

Additional relevant MeSH terms:
Apnea
Hypertension
Sleep Apnea Syndromes
Sleep Apnea, Obstructive
Respiration Disorders
Respiratory Tract Diseases
Signs and Symptoms, Respiratory
Signs and Symptoms
Vascular Diseases
Cardiovascular Diseases
Sleep Disorders, Intrinsic
Dyssomnias
Sleep Disorders
Nervous System Diseases

ClinicalTrials.gov processed this record on August 21, 2014