Weight Gain After CPAP Treatment in Patients With Obstructive Sleep Apnea

Not Applicable

Completed

• Conditions: Obstructive Sleep Apnea
• Interventions: Device: CPAP withdrawal

• Registration Number: NCT03567317
• Lead Sponsor: University of Sao Paulo General Hospital

Brief Summary

The purpose of this trial is to investigate the mechanisms leading to weight gain during CPAP treatment for obstructive sleep apnea (OSA).

Detailed Description

Obesity and obstructive sleep apnea share a bidirectional relationship. While obesity is a major risk factor for OSA, OSA may contribute to weight gain. Recent evidence suggests that OSA treatment is associated with weight gain. The mechanisms involved in weight gain after OSA treatment are not known. The purpose of this study is to determine the mechanisms of weight gain during CPAP treatment for severe OSA leads. The investigators hypothesis is that CPAP leads to a decrease in energy expenditure and prevents the elimination of extracellular fluid that is accumulated during the day. In order to test this hypothesis, 20 patients with severe OSA aged between 50 and 80 years old, under regular treatment with CPAP, will be invited to participate. Using a cross-over design, the investigators will perform bioelectric impedance 5 times over 24 hours in order to assess the circadian effect of fluid accumulation in two different conditions: during CPAP treatment and 7 days after CPAP withdrawal. A full polysomnography will be performed during CPAP withdrawal to confirm severe OSA and during CPAP treatment to confirm adequate control of respiratory events. In addition, basal metabolic rate, hematocrit, serum BNP, urinary sodium, creatinine and osmolality will be determined in the morning during the CPAP and CPAP withdrawal periods.

Study Timeline

• Study Start: 2018-03-01
• Study First Submitted: 2018-06-11
• Study First Submitted QC: 2018-06-21
• Study First Posted: 2018-06-25
• Primary Completion: 2019-07-01
• Study Completion: 2019-12-01
• Status Verified: 2020-04
• Last Update Submitted: 2020-04-01
• Last Update Posted: 2020-04-03

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 22

Inclusion Criteria

• Patients with a diagnosis of severe OSA (AHI>30 events/h)
• 50 and 80 years old
• regular treatment with CPAP with an average daily use of >4hours

Exclusion Criteria

• congestive heart failure
• renal insufficiency
• hepatic failure
• urinary incontinency
• diuretic therapy

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
CPAP withdrawal	CPAP withdrawal	According to study design, patients will be randomized to remain on CPAP during the initial study visit or withdraw CPAP one week before. If randomized to withdraw CPAP at the second study visit, patients will withdraw CPAP one week before.

Primary Outcome Measures

Name	Time	Method
Extracellular fluid volume	Seven days	Extracellular fluid volume accumulation will be assessed by bioelectrical impedance after 7 days of CPAP or CPAP withdrawal.

Secondary Outcome Measures

Name	Time	Method
Basal metabolic rate	24 hours	Basal metabolic rate will be assessed by indirect calorimetry after 7 days of CPAP or CPAP withdrawal.
Weight change	7 days	Weight change during CPAP use

Trial Locations

Locations (1)

Sleep Laboratory, Heart Institute, Pulmonary Division, Hospital das Clínicas da Universidade de São Paulo; 🇧🇷 Sao Paulo, Brazil