The Effects of Continuous Positive Airway Pressure (CPAP) on Sympathetic Activity in Different Sites of Activation

Phase 3

• Conditions: Radionuclide Imaging (MIBG Scintigraphy); Exercise Test; Blood Pressure Monitoring, Ambulatory; Sympathetic Nerve Activity; Catecholamines
• Interventions: Device: CPAP

• Registration Number: NCT01336335
• Lead Sponsor: University of Sao Paulo

Brief Summary

Recent evidences suggest that obstructive sleep apnea (OSA) can contribute to cardiovascular disease even in the absence of hypertension. However, there are few data regarding the impact of OSA on the sympathetic system in apparently normotensive patients with OSA as well as the impact of treatment with continuous positive airway pressure in different sites of activation (heart, peripheral nerves and circulating catecholamines)

Detailed Description

Not available

Study Timeline

• Status Verified: 2010-07
• Study Start: 2010-07
• Study First Submitted: 2011-04-13
• Study First Submitted QC: 2011-04-13
• Last Update Submitted: 2011-04-13
• Study First Posted: 2011-04-15
• Last Update Posted: 2011-04-15
• Primary Completion: 2011-07
• Study Completion: 2011-07

Recruitment & Eligibility

• Status: UNKNOWN
• Sex: Male
• Target Recruitment: 20

Inclusion Criteria

• Severe OSA males

Exclusion Criteria

• Smoking

  • Sustained Hypertension
  • Heart failure
  • Diabetes
  • Renal diseases
  • Under use of any medication
  • Under treatment for OSA

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
CPAP	CPAP	OSA treatment with CPAP

Primary Outcome Measures

Name	Time	Method
improvement in sympathetic activity in muscle sympathetic nerve activity (MSNA)	3 months	Improvement in MSNA will be quantified as burst frequency over time (bursts per minute) and as burst frequency corrected for heart rate values (bursts per 100 heartbeats)in the begining and after 3 months.

Secondary Outcome Measures

Name	Time	Method
improvement in sympathetic activity evaluated in different sites of activation	3 months	All measurement will be performed at the begining and after 3 months. Blood: blood and 24 hour urine will be collected for norepinephrine quantification.; Heart: Early (15 min) and delayed (3 hr) planar images will be taken after injection of (123)I-MIBG. The mean counts of the whole heart and the mediastinum will be obtained to calculate heart-to-mediastinum count ratios from the early images (H/Me) and from the delayed images (H/Md) and the myocardial washout rate (WR).; Blood pressure: 24 hour ambulatory blood pressure monitoring and blood pressure during exercise test (treadmill test)

Trial Locations

Locations (1)

Heart Institute; 🇧🇷 São Paulo, Brazil