Now Available for Public Comment: Notice of Proposed Rulemaking (NPRM) for FDAAA 801 and NIH Draft Reporting Policy for NIH-Funded Trials

Efficacy Study of CPAP on Nitrate and Norepinephrine Levels in Severe and Mild-moderate Sleep Apnea (SABIO)

This study has been completed.
Information provided by (Responsible Party):
Paula Pinto, University of Lisbon Identifier:
First received: November 17, 2012
Last updated: January 16, 2013
Last verified: January 2013

Reduced plasma nitrate (NOx) levels and increased urinary norepinephrine (U-NE) levels have been described in severe obstructive sleep apnea (OSA), and are reverted by continuous positive airway pressure (CPAP). The investigators wanted to know the effect of CPAP on these biomarkers in mild-moderate OSA.

Condition Intervention
Obstructive Sleep Apnea
Device: CPAP

Study Type: Interventional
Study Design: Endpoint Classification: Efficacy Study
Intervention Model: Single Group Assignment
Masking: Open Label
Primary Purpose: Treatment
Official Title: Effects of CPAP on Nitrate and Norepinephrine Levels in Severe and Mild-moderate Sleep Apnea

Resource links provided by NLM:

Further study details as provided by University of Lisbon:

Primary Outcome Measures:
  • Plasma nitrate (NOx) levels [ Time Frame: one month ] [ Designated as safety issue: No ]
    After sleep apnea diagnosis, measurements of plasma NOx at 11 pm, 4 am and 7 am were obtained at baseline and after 1 month of CPAP.

Secondary Outcome Measures:
  • 24 h Blood pressure [ Time Frame: one month after CPAP ] [ Designated as safety issue: No ]
    Ambulatory BP were obtained at baseline and after 1 month of CPAP.

  • Urinary norepinephrine (U-NE) levels [ Time Frame: One month ] [ Designated as safety issue: No ]
    After sleep apnea diagnosis, measurements of urinary norepinephrine levels were obtained at baseline and after 1 month of CPAP.

Enrollment: 67
Study Start Date: July 2004
Study Completion Date: December 2008
Primary Completion Date: December 2008 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: CPAP treatment
67 consecutive male patients with OSA were recruited: 36 with mild-moderate OSA and 31 with severe OSA. Data were collected in all subjects at baseline and after 1 month of CPAP.
Device: CPAP
CPAP adaptation was performed by a sleep technician and the patients were instructed to use this for 1 month.
Other Name: Automated pressure setting device (AutoSet Spirit, ResMed)

Detailed Description:

The investigators aimed to compare NOx and U-NE levels and blood pressure (BP) between male patients with mild-moderate and severe OSA and determine the impact of 1 month of CPAP therapy on these parameters.

The investigators undertook a prospective study of 67 consecutive OSA patients (36 mild-moderate, 31 severe). Measurements of plasma NOx at 11 pm, 4 am and 7 am, 24-h U-NE and ambulatory BP were obtained at baseline and after 1 month of CPAP.


Ages Eligible for Study:   20 Years to 65 Years
Genders Eligible for Study:   Male
Accepts Healthy Volunteers:   No

Inclusion Criteria:

- Diagnosis of obstructive sleep apnea

Exclusion Criteria:

  • current smoker
  • respiratory disease
  • cardiac disease (except for arterial hypertension)
  • renal disorder
  • hepatic disorder
  • psychiatric disorder
  • diabetes mellitus
  • dyslipidemia
  • rhinitis
  • sinusitis
  • acute illness
  • daytime hypoxemia or hypercapnia
  • therapy with oral nitrates
  • therapy with angiotensin-converting enzyme inhibitors
  • therapy with beta-blockers
  • therapy with statins
  • therapy with non-steroidal anti-inflammatory drugs
  • presence of central respiratory events
  • previous CPAP therapy
  • previous uvulopalatopharyngoplasty
  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: NCT01769807

Hospital Pulido Valente
Lisbon, Portugal, 1769-001
Sponsors and Collaborators
University of Lisbon
Principal Investigator: Paula G Pinto, PhD University of Lisbon
  More Information

No publications provided by University of Lisbon

Additional publications automatically indexed to this study by Identifier (NCT Number):
Responsible Party: Paula Pinto, PhD, University of Lisbon Identifier: NCT01769807     History of Changes
Other Study ID Numbers: CEDOC, Fundação Ciência e Tecnologia
Study First Received: November 17, 2012
Last Updated: January 16, 2013
Health Authority: Portugal: Ethics Committee for Clinical Research

Keywords provided by University of Lisbon:
Sleep apnea
CPAP treatment
Plasma nitrate
Urinary norepinephrine
Blood pressure

Additional relevant MeSH terms:
Sleep Apnea Syndromes
Sleep Apnea, Obstructive
Nervous System Diseases
Respiration Disorders
Respiratory Tract Diseases
Signs and Symptoms
Signs and Symptoms, Respiratory
Sleep Disorders
Sleep Disorders, Intrinsic
Adrenergic Agents
Adrenergic Agonists
Adrenergic alpha-Agonists
Autonomic Agents
Cardiovascular Agents
Molecular Mechanisms of Pharmacological Action
Neurotransmitter Agents
Peripheral Nervous System Agents
Pharmacologic Actions
Physiological Effects of Drugs
Therapeutic Uses
Vasoconstrictor Agents processed this record on November 20, 2014