Early Signs of Atherosclerosis in Obstructive Sleep Apnea: Effects of Treatment

Obstructive Sleep Apnea Clinical Trial

Official title:

Effects of Continuous Positive Airway Pressure (CPAP) on Early Signs of Atherosclerosis in Patients With Obstructive Sleep Apnea: a Randomized Study

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT00400543
• Other study ID #: SDC 2431/04/051
• Status: Completed
• Phase: Phase 4
• First received: November 16, 2006
• Last updated: November 16, 2006
• Start date: January 2004
• Est. completion date: July 2006

Study information

• Verified date: November 2006
• Source: University of Sao Paulo
• Contact: n/a
• Is FDA regulated: No
• Health authority: Brazil: National Committee of Ethics in Research
• Study type: Interventional

Clinical Trial Summary

Obstructive sleep apnea (OSA) is associated with adverse cardiovascular outcomes, including acute myocardial infarction and stroke. Atherosclerosis is an important step for these events. Recent studies demonstrated the independent association between OSA and validated markers of atherosclerosis. However, the impact of treatment with continuous positive airway pressure (CPAP) on these markers is unknown.

The purpose of this study is to determine whether CPAP therapy can reverses early signs of atherosclerosis in apparently healthy OSA patients.

Description:

Obstructive sleep apnea (OSA) is characterized by recurrent episodes of partial or complete obstruction of the upper airway during sleep resulting in oxygen desaturation and arousals from sleep. OSA is recognized as an important public health problem, affecting 9 and 24 % of middle-aged females and males, respectively. There is now compelling evidence that severe OSA is associated with increased cardiovascular morbidity and mortality, mainly due to acute myocardial infarction and stroke. Moreover, the current standard treatment with application of continuous positive airway pressure (CPAP) during the night was associated with decreased non-fatal and fatal cardiovascular events.

There are several mechanisms associated with OSA that are potentially harmful to the cardiovascular system, including sympathetic activation, systemic inflammation, production of reactive oxygen species, and endothelial dysfunction. Together, all these factors could contribute to atherosclerosis progression, a key mechanism involved in the genesis of myocardial infarction and stroke. For instance, we recently described the presence of early signs of atherosclerosis in otherwise healthy OSA subjects as characterized by alterations in validated markers of atherosclerosis, including increased arterial stiffness, evaluated by pulse wave velocity (PWV), as well as intima-media thickness (IMT) and carotid diameter (CD). All theses vascular abnormalities correlated significantly with the severity of the OSA.

In this study, we will perform a randomized study to evaluate the impact of CPAP therapy on PWV, IMT and CD as well as in catecholamine and C reactive protein. We made the hypothesis that CPAP promotes beneficial effects on atherosclerosis, independent of the other factors, such as blood pressure and cholesterol levels. To this end, we only will study young OSA patients that were free of co-morbidities. Patients will be randomized to no treatment (Control) or CPAP for 4 months. Evalutations will be performed at baseline and after 4 months.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 24
• Est. completion date: July 2006
• Accepts healthy volunteers: No
• Gender: Male
• Age group: 30 Years to 60 Years

Eligibility

Inclusion Criteria:

• Males with recent sleep study (<1 month) showing severe obstructive sleep apnea, defined as at least 30 events of apnea and hypopnea per hour of sleep.

Exclusion Criteria:

• Age >60 years old, body mass index (BMI) >35 kg/m2, diabetes mellitus, hypertension, cerebrovascular, aortic, heart, and valvar heart diseases, renal failure, arrhythmias, smoking habit, and chronic use of medications, including statins.

Study Design

Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Single Blind, Primary Purpose: Treatment

Related Conditions & MeSH terms

• Apnea
• Atherosclerosis
• Obstructive Sleep Apnea
• Sleep Apnea Syndromes
• Sleep Apnea, Obstructive

Intervention

Device:
• Continuous positive airway pressure (CPAP)

Locations

Country	Name	City	State
Brazil	Heart Institute (InCor) - University of São Paulo Medical School	São Paulo

Sponsors (3)

Lead Sponsor	Collaborator
University of Sao Paulo	Conselho Nacional de Desenvolvimento Científico e Tecnológico, Fundação de Amparo à Pesquisa do Estado de São Paulo

Country where clinical trial is conducted

Brazil, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Arterial stiffness (evaluated by PWV)
Primary	Intima media thickness (IMT)
Primary	Carotid diameter (CD)
Secondary	24h blood pressure monitoring
Secondary	plasma catecholamine
Secondary	C-reactive protein (CRP)