Weight Loss and Obstructive Sleep Apnea

Effects of Energy Restriction on Sleep Apnea, Sympathetic Activity, Oxidative Stress, Inflammatory Biomarkers, Endothelial Function, Body Adiposity, Metabolic Profile and Blood Pressure in Obese Patients With Obstructive Sleep Apnea

The purpose of this study is to evaluate the effects of moderate energy restriction on the body adiposity, severity of OSA, blood pressure, sympathetic activity, oxidative stress, inflammatory biomarkers, metabolic profile and endothelial function in obese patients with OSA.

Study Overview

• Status: Completed
• Conditions: Obstructive Sleep Apnea
• Intervention / Treatment: Behavioral: Energy Restriction

Detailed Description

Introduction: Nutritional intervention for weight loss is one of the treatment options for obstructive sleep apnea (OSA) in patients with excess body adiposity. However, the effects of moderate energy restriction, recommended by current guidelines for the treatment of obesity, on OSA are not yet known. Objective: To evaluate the effects of moderate energy restriction on the body adiposity; severity of OSA; blood pressure; sympathetic activity; oxidative stress; inflammatory biomarkers; metabolic profile and endothelial function in obese patients with OSA. Methods: A 16-week randomized clinical trial, involving 21 subjects with obesity (grade I or II), aged 20-55 years and presenting an apnea/hipopnea index (AHI) > 5 events/h. Participants were randomized into 2 groups: 11 in the energy restriction group (ERG) and 10 in the control group (CG). The ERG was instructed to follow an energy-restricted diet (-800 kcal/day) and the CG was advised not to change their food intake. At the beginning and at the end of the study, participants underwent evaluation of: OSA with the equipment Watch- PAT200® including the determination of the following parameters of OSA severity: AHI, minimum O2 saturation, number of O2 desaturations >4%; body adiposity (weight, %body fat and circumferences of waist, hip and neck); blood pressure (BP); sympathetic nervous system activity (plasma levels of catecholamines); inflammatory biomarkers (c-reactive protein and adiponectin); oxidative stress (malondialdehyde); metabolism of glucose (glucose, insulin and HOMA-IR) and lipids (total cholesterol and fractions and triglycerides); and endothelial function (index of reactive hyperemia evaluated by Endo - PAT 2000® and cellular adhesion molecules). The statistical analysis was performed with the software STATA v. 10. The level of statistical significance was p < 0.05.

• Study Type: Interventional
• Enrollment (Actual): 21
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Brazil
  • Rio de Janeiro, Brazil, 20.551-030
    • Discipline of Clinical and Experimental Pathophysiology, CLINEX

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 20 years to 55 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• age between 20-55 years
• body mass index (BMI) ≥ 30 kg/m2 and < 40 kg/m2

Exclusion Criteria:

• smoking
• Use of dietary supplements
• Use of medications that could interfere in body weight, metabolic profile and blood pressure
• Use of permanent pacemaker; use of α-adrenergic blocking agents
• Recent changes (within previous 6 months) in body weight (> 3 kg), in dietary intake and in intensity or frequency of physical exercise
• Diagnosis of diabetes mellitus, hypertension, dyslipidemia (with drug treatment) and kidney disease
• Clinical history of thyroid dysfunction, angina pectoris, peripheral vascular disease, peripheral neuropathy, heart failure, liver failure, chronic pulmonary disease, gastroesophageal reflux disease, myocardial infarction and stroke; finger deformity that prevents the proper use of the sensors that are necessary to evaluate OSA and endothelial function; and previous bilateral cervical-thoracic sympathectomy
• Pregnant or lactating women were not allowed into the study

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Energy restriction group; The energy restriction group was instructed to follow an energy-restricted diet (-800 kcal/day).	Behavioral: Energy Restriction; The energy restriction group was instructed to follow an energy-restricted diet (-800 kcal/day).
No Intervention: Control group; The control group was advised not to change their food intake.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Apnea/hipopnea index	16 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Blood pressure		16 weeks
Sympathetic activity	Plasma levels of catecholamines	16 weeks
Oxidative stress	Serum levels of malondialdehyde	16 weeks
Inflammatory biomarkers	Circulating levels of high-sensitivity C reactive protein and adiponectin	16 weeks
Metabolic profile	Fasting plasma glucose, insulin, total cholesterol, HDL-cholesterol, LDL-cholesterol and triglycerides	16 weeks
Endothelial function	Circulating levels of cellular adhesion molecules (intercellular adhesion molecule 1 and P-selectin). Endothelial function was also evaluated by the PAT method, using Endo-PAT 2000®.	16 weeks

Collaborators and Investigators

• Sponsor: Rio de Janeiro State University
• Investigators: Principal Investigator: Antonio Felipe Sanjuliani, Dr., Rio de Janeiro State University

Study record dates

Study Major Dates

• Study Start: March 1, 2012
• Primary Completion (Actual): October 1, 2013
• Study Completion (Actual): October 1, 2013

Study Registration Dates

• First Submitted: June 27, 2014
• First Submitted That Met QC Criteria: July 30, 2014
• First Posted (Estimate): August 1, 2014

Study Record Updates

• Last Update Posted (Estimate): August 1, 2014
• Last Update Submitted That Met QC Criteria: July 30, 2014
• Last Verified: July 1, 2014

More Information

Terms related to this study

• Keywords: Obesity; Obstructive sleep apnea; Weight loss; Endothelial function; Sympathetic activity; Metabolic profile
• Additional Relevant MeSH Terms: Nervous System Diseases; Respiratory Tract Diseases; Respiration Disorders; Sleep Disorders, Intrinsic; Dyssomnias; Sleep Wake Disorders; Signs and Symptoms, Respiratory; Sleep Apnea Syndromes; Sleep Apnea, Obstructive; Apnea
• Other Study ID Numbers: CLINEX05