We updated the design of this site on December 18, 2017. Learn more.
ClinicalTrials.gov Menu

Influence of nCPAP on Metabolic Consequences Associated With OSAS

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
ClinicalTrials.gov Identifier: NCT00435643
Recruitment Status : Completed
First Posted : February 15, 2007
Last Update Posted : November 20, 2007
Information provided by:
Federal University of São Paulo

Brief Summary:
Context: Obstructive sleep apnea syndrome (OSAS) is associated with cardiovascular morbidity. Recurrent episodes of occlusion of upper airways during sleep result in hormonal changes that may predispose to high cardiovascular risk.These risks can rapidly be reduced by effective nasal continuous positive airway pressure (nCPAP) therapy Objective: To evaluate hypothalamic pituitary adrenal axis, insulin resistance, blood pressure values and adipokines in severe obese patients with and without OSAS and to determine if continuous positive airway pressure therapy (nCPAP) influenced responses.

Condition or disease Intervention/treatment
Obstructive Sleep Apnea Syndrome Obesity Procedure: nasal continuous positive airway pressure

Detailed Description:

Background: There is evidence that obstructive sleep apnea syndrome (OSAS) increases the risk of cardiovascular events. Sympathetic nervous system and hypothalamic-pituitary-adrenal (HPA) axis activation may be the mechanism of this relationship. We evaluate HPA axis and metabolic consequences in obese patients with and without OSAS and we determine if continuous positive airway pressure therapy (nCPAP) influenced responses.

Methods: Plasma inflammatory cytokines, insulin resistance index, 24-hour ambulatory blood pressure monitoring and overnight cortisol suppression test with 0.25 mg of dexamethasone were performed in 22 severe obese patients with OSAS and 23 obese controls. Ten patients with severe apnea were re-evaluated three months after nCPAP therapy.

Results: Body mass index, abdominal circumference, blood pressure levels and insulin resistance indexes of OSAS patients and obese controls were very similar. In OSAS patients, adiponectin (p<0.05) and salivary cortisol suppression pos DEX (p<0.05) were lower, while heart rate (p<0.05) and TNF-alpha levels (p<0.05) were higher compared with obese controls. After nCPAP therapy, patients showed a reduction in heart rate (p=0.036) and a higher cortisol suppression after dexamethasone (p=0.001) and there were no differences in insulin resistance (HOMA p=0.139), arterial blood pressure (p=0.183) and adipokines compared with baseline. Cortisol suppression was positively correlated with the improvement of apnea hypopnea index while on nCPAP therapy (r= 0.799, p=0.010).

Conclusions: Patients with OSAS present nocturnal hypercortisolism, hyperactivity of sympathetic central nervous system, a higher degree of inflammation and hypoadiponectinemia independent of the body mass index. Furthermore, hyperactivity of HPA axis and sympathetic nervous system are recovered by nCPAP.

Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 45 participants
Allocation: Non-Randomized
Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Basic Science
Official Title: Improvement in Hypothalamic-Pituitary-Adrenal Axis Function After Continuous Positive Airway Pressure Therapy in Obstructive Sleep Apnea Syndrome
Study Start Date : October 2004
Study Completion Date : March 2006

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Sleep Apnea
U.S. FDA Resources

Arm Intervention/treatment
Active Comparator: A
10 patients with severe OSAS (Apnea Hypopnea Index of more than 30 events per hour of sleep) were treated with nCPAP for three months and all mentioned measurements above were repeated.
Procedure: nasal continuous positive airway pressure
After an average interval of three months, 10 patients with severe OSAS (AHI of more than 30 events per hour of sleep) treated with a mean nCPAP pressure of 11.2 ± 0.7 cm of H2O were reassessed and all mentioned measurements above were repeated

Primary Outcome Measures :
  1. To explore the interactive mechanisms of HPA axis, sympathetic nervous system activation, inflammatory cytokines, insulin resistance and hypertension in patients with and without sleep apnea, excluding the interference of the degree of fat accumulation. [ Time Frame: one day ]

Secondary Outcome Measures :
  1. To evaluate low-dose dexamethasone-induced cortisol suppression and circadian rhythm of cortisol secretion in severe obese patients with sleep apnea in response to treatment with continuous positive airway pressure. [ Time Frame: three months ]

Information from the National Library of Medicine

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, Learn About Clinical Studies.

Ages Eligible for Study:   18 Years to 65 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Aged from 18 to 65 years
  • Body mass index between 35-60 who were submitted to polysomnography

Exclusion Criteria:

  • History of smoking
  • Sleep apnea treatment
  • Cardiovascular disease
  • Malignancies tumor
  • Thyroid disorders
  • Depression
  • Subjects with known diabetes mellitus on medications
  • Chronic renal or hepatic failure
  • On hormonal replacement therapy, as well as use of medication that could potentially affect steroid hormone or cytokines secretion (alcohol, psychotropics, steroids, sympathomimetics, beta-blockers).

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT00435643

Universidade Federal de Sao Paulo
Sao Paulo, SP, Brazil, 04023-062
Sponsors and Collaborators
Federal University of São Paulo
Principal Investigator: Gláucia Carneiro, MD UNIFESP-EPM

Publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
ClinicalTrials.gov Identifier: NCT00435643     History of Changes
Other Study ID Numbers: 12383
First Posted: February 15, 2007    Key Record Dates
Last Update Posted: November 20, 2007
Last Verified: November 2007

Keywords provided by Federal University of São Paulo:
Sleep apnea,
adiponectin ,
HPA axis

Additional relevant MeSH terms:
Sleep Apnea Syndromes
Sleep Apnea, Obstructive
Pathologic Processes
Respiration Disorders
Respiratory Tract Diseases
Signs and Symptoms, Respiratory
Signs and Symptoms
Sleep Disorders, Intrinsic
Sleep Wake Disorders
Nervous System Diseases