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Influence of nCPAP on Metabolic Consequences Associated With OSAS

This study has been completed.
Information provided by:
Federal University of São Paulo Identifier:
First received: February 14, 2007
Last updated: November 19, 2007
Last verified: November 2007
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 Intervention
Obstructive Sleep Apnea Syndrome Obesity Procedure: nasal continuous positive airway pressure

Study Type: Interventional
Study Design: 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

Resource links provided by NLM:

Further study details as provided by Federal University of São Paulo:

Primary Outcome Measures:
  • 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:
  • 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 ]

Enrollment: 45
Study Start Date: October 2004
Study Completion Date: March 2006
Arms Assigned Interventions
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

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.


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).
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Please refer to this study by its identifier: 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
  More Information

Publications automatically indexed to this study by Identifier (NCT Number): Identifier: NCT00435643     History of Changes
Other Study ID Numbers: 12383
Study First Received: February 14, 2007
Last Updated: November 19, 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 processed this record on August 17, 2017