Clinical trial NCT00633711: Effects of Obstructive Sleep Apnea Treatment by Fixed CPAP and by Auto-CPAP (Somnosmart2)
Official title: Differential Effects of Chronic Treatment of OSAS by CPAP and SOMNOsmart2 on Norepinephrine and Blood Pressure
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE4
Conditions: Obstructive Sleep Apnea Syndrome
Keywords: OSAS
blood pressure
sympathetic nervous system
treatment
CPAP
Lead sponsor: Fondazione C.N.R./Regione Toscana "G. Monasterio", Pisa, Italy
Sponsor class: OTHER_GOV
Collaborators: name: Weinmann Geräte für Medizin GmbH + Co. KG
First posted: 2008-03-12
Enrollment: 17
Sex: ALL
Minimum age (years): 25
Maximum age (years): 60
Standard ages: ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

Brief summary: The main purpose of this study is to investigate if treatment of obstructive sleep apnea syndrome (OSAS) by continuous positive airway pressure (CPAP) given by a traditional CPAP device administering a fixed air pressure, or by one automatic CPAP device ("Somnosmart2", Weinmann, Hamburg) administering variable pressures, have different effects on sympathetic nervous system tone (as reflected by urinary excretion of norepinephrine and its catabolite normetanephrine) and on blood pressure.

Detailed description: A nocturnal home cardiorespiratory recording will performed for diagnosis of OSA. During the same night, patients will be asked to collect their urines. Twentyfour-hour ambulatory BP monitoring (ABPM) will be performed starting from the next morning. After analysis of the polygraphic recording, subjects with AHI \<15 will be excluded from the study, while CPAP will be proposed as a treatment to the other patients.

Before starting treatment, a full night standard polysomnography will be performed: in subjects assigned to fixed CPAP for attended CPAP titration; in the other subjects during application of the Somnosmart2 device, to verify if obstructive events are adequately eliminated by it.

After analysis of polysomnography, patients will be given a fixed CPAP or the auto-CPAP device for nocturnal home use. Two months later, compliance to treatment will be verified measured by the in-built time counter of the devices. Then, cardiorespiratory monitoring during application of the device used for treatment, nocturnal urine collection and 24-hour ABPM will be repeated.

Eligibility criteria: Inclusion Criteria:

* Obstructive sleep apnea syndrome deserving CPAP treatment

Exclusion Criteria:

* current pharmacological treatment

Primary outcomes:
measure: Blood pressure and urinary catecholamines after conventional or auto-CPAP
timeFrame: 2 months
Secondary outcomes:
measure: Relationship between catecholamines / blood pressure changes and compliance to treatment
timeFrame: 2 months
Other outcomes:
Locations:
city: Palermo
country: Italy
facility: National Research Council - Institute of Biomedicine and Molecular Immunology (CNR - IBIM)
Study officials:
affiliation: Fondazione C.N.R./Regione Toscana "G. Monasterio", Pisa, Italy
name: Oreste Marrone, MD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Patruno V, Aiolfi S, Costantino G, Murgia R, Selmi C, Malliani A, Montano N. Fixed and autoadjusting continuous positive airway pressure treatments are not similar in reducing cardiovascular risk factors in patients with obstructive sleep apnea. Chest. 2007 May;131(5):1393-9. doi: 10.1378/chest.06-2192.
citation: Bazzano LA, Khan Z, Reynolds K, He J. Effect of nocturnal nasal continuous positive airway pressure on blood pressure in obstructive sleep apnea. Hypertension. 2007 Aug;50(2):417-23. doi: 10.1161/HYPERTENSIONAHA.106.085175. Epub 2007 Jun 4.
citation: Alajmi M, Mulgrew AT, Fox J, Davidson W, Schulzer M, Mak E, Ryan CF, Fleetham J, Choi P, Ayas NT. Impact of continuous positive airway pressure therapy on blood pressure in patients with obstructive sleep apnea hypopnea: a meta-analysis of randomized controlled trials. Lung. 2007 Mar-Apr;185(2):67-72. doi: 10.1007/s00408-006-0117-x. Epub 2007 Mar 28.
citation: Haentjens P, Van Meerhaeghe A, Moscariello A, De Weerdt S, Poppe K, Dupont A, Velkeniers B. The impact of continuous positive airway pressure on blood pressure in patients with obstructive sleep apnea syndrome: evidence from a meta-analysis of placebo-controlled randomized trials. Arch Intern Med. 2007 Apr 23;167(8):757-64. doi: 10.1001/archinte.167.8.757.
citation: Parati G, Lombardi C, Narkiewicz K. Sleep apnea: epidemiology, pathophysiology, and relation to cardiovascular risk. Am J Physiol Regul Integr Comp Physiol. 2007 Oct;293(4):R1671-83. doi: 10.1152/ajpregu.00400.2007. Epub 2007 Jul 25.
citation: Narkiewicz K, Somers VK. Sympathetic nerve activity in obstructive sleep apnoea. Acta Physiol Scand. 2003 Mar;177(3):385-90. doi: 10.1046/j.1365-201X.2003.01091.x.