Sleep Apnea and Oxidative Stress and Nitric Oxide

Sponsor

Sociedad Española de Neumología y Cirugía Torácica (Other)

Overall Status

Completed

CT.gov ID

NCT00547937

Collaborator

Fondo de Investigacion Sanitaria (Other)

Enrollment

Location

Arms

Duration (Months)

Patients Per Site Per Month

Study Details

Study Description

Brief Summary

Background: Previous studies present contradictory data concerning obstructive sleep apnea syndrome (OSAS), lipid oxidation and nitric oxide (NO) bioavailability. This study was aimed: (1) to compare the concentration of 8-isoprostane and total nitrate and nitrite (NOx) in plasma of middle aged males with OSAS and no other known comorbidity and carefully matched healthy controls of the same age and gender; and (2) to test the hypothesis that nasal continuous positive airway pressure (CPAP) therapy, might attenuate oxidative stress and nitrate deficiency.

Condition or Disease	Intervention/Treatment	Phase
Sleep Apnea Syndromes	Device: nasal continuous positive airway pressure (CPAP) therapy	Phase 4

Detailed Description

We performed a single-center, prospective, randomized, double-blind, placebo-controlled and cross-over clinical study, in which patients received CPAP and sham therapy for two 12-week periods. Baseline measurements in healthy controls matched for age and gender were also obtained. At recruitment, 24-h blood pressure monitoring (ABPM), an echocardiogram (to rule out any cardiac dysfunction) and a sleep study was obtained in all participants . After fasting overnight, a venous blood sample (anti-coagulated with dipotassium EDTA, for 8-isoprostane and total nitrate and nitrite concentration (NOx) determinations) and a urine sample were collected in all of them between 08:00 and 10:00 hours. Within 30 minutes of blood collection, plasma was obtained by centrifugation at 3000 rpm for 15 min. All plasma samples were stored at -60°C until analysis. Patients with OSAS underwent a full-night CPAP titration study using an automated pressure setting device (Auto Set; ResMed, Sydney, Australia). Compliance with therapy was obtained from a built-in run-time counter. After 12 weeks, CPAP device was switched to the alternate mode of therapy and ABPM,, plasma and urine sampling were repeated in patients

Study Design

Study Type:

Interventional

Actual Enrollment :

31 participants

Allocation:

Randomized

Intervention Model:

Crossover Assignment

Masking:

Triple (Participant, Care Provider, Investigator)

Official Title:

Nitrate and Oxidative Stress in Sleep Apnea Syndrome. Effect of Continuous Positive Airway Pressure

Study Start Date :

May 1, 2001

Actual Study Completion Date :

Dec 1, 2003

Arms and Interventions

Arm	Intervention/Treatment
Sham Comparator: Sham-CPAP The sham CPAP device consisted of a conventional CPAP device, in which the area of the exhalation port was amplified, thereby nearly cancelling nasal pressure; an orifice resistor was connected between the tubing and the CPAP unit that loads the blower with the same airflow resistance as in effective CPAP	Device: nasal continuous positive airway pressure (CPAP) therapy Nocturnal ventilation through a nasal mask to avoid sleep apneas
Active Comparator: CPAP	Device: nasal continuous positive airway pressure (CPAP) therapy Nocturnal ventilation through a nasal mask to avoid sleep apneas

Arm

Intervention/Treatment

Sham Comparator: Sham-CPAP

The sham CPAP device consisted of a conventional CPAP device, in which the area of the exhalation port was amplified, thereby nearly cancelling nasal pressure; an orifice resistor was connected between the tubing and the CPAP unit that loads the blower with the same airflow resistance as in effective CPAP

Device: nasal continuous positive airway pressure (CPAP) therapy

Nocturnal ventilation through a nasal mask to avoid sleep apneas

Active Comparator: CPAP

Device: nasal continuous positive airway pressure (CPAP) therapy

Nocturnal ventilation through a nasal mask to avoid sleep apneas

Outcome Measures

Primary Outcome Measures

concentration of 8-isoprostane and total nitrate and nitrite (NOx) in plasma [3 months]

Eligibility Criteria

Criteria

Ages Eligible for Study:

N/A and Older

Sexes Eligible for Study:

Male

Accepts Healthy Volunteers:

Yes

Inclusion Criteria:

apnea-hypopnea index (AHI) ≥10 h-1
excessive daytime sleepiness defined by an Epworth scale score ≥11 points
no treatment for OSAS. Inclusion criteria for healthy control subjects were AHI <5 h-1 and Epworth sleepiness scale <10.

Exclusion Criteria:

unwillingness or inability to participate in the study
obstructive or restrictive lung disease as identified by pulmonary function testing
use of cardioactive drugs
cardiac rhythm disturbances, including sinus bradycardia and sinus tachycardia
known arterial hypertension, or 24-hour mean blood pressure of 135 and/or 85 mm Hg or more
left ventricular ejection fraction <50%, ischemic or valve heart disease, hypertrophic, restrictive or infiltrative cardiomyopathy, pericardial disease or stroke, by history, physical examination, ECG, chest radiography, conventional exercise stress testing, and echocardiography
diabetes mellitus, by history or 2 random blood glucose levels ≥126 mg/dl
morbid obesity (body mass index >40 Kg/m2)
daytime hypoxemia (PaO2 <70 mm Hg) or hypercapnia (PaCO2 >45 mm Hg)
need to change medication
hospital admission for 10 or more days
average nightly CPAP usage less than 3.5 hours.