Effects of CPAP on Energy Expenditure and Energy Intake in Obstructive Sleep Apnea
Obstructive sleep apnea (OSA) is characterized by recurrent episodes of partial or complete loss of airflow during sleep, due to narrowing or closure of the upper airway. The resulting hypoxia has many cardiometabolic consequences, and leads to a disruption of sleep quality including reductions in the expression of rapid eye movement (REM) sleep and slow wave sleep (SWS). Patients also frequently experience excessive daytime sleepiness (EDS), which, when present with OSA, defines the clinical entity OSA syndrome (OSAS). Obesity is the leading risk factor for the development of OSA. Interestingly, it has been suggested that the disorder itself may contribute to further weight gain, presenting a vicious cycle wherein OSA and obesity perpetuate each other. OSAS may promote weight gain by placing patients in a state of positive energy balance characterized by low levels of physical activity and disrupted patterns of appetite-regulating hormones. Continuous positive airway pressure (CPAP), the gold-standard treatment of OSAS, may improve energy balance in these patients, although this has not yet been adequately studied. The current proposal is for a randomized, placebo-controlled, crossover trial investigating the effects of 2 months of active and sham CPAP on energy balance in obese patients with moderate-to-severe OSA and EDS. Patients will be instructed to use active or sham CPAP at home each night throughout the 2-month treatment phases. At the conclusion of each 2-month treatment phase, the investigators will measure levels of free-living physical activity, sleepiness, sleep quality, body composition, energy metabolism, appetite-regulating hormones, hunger, and ad libitum food intake. It is hypothesized that active compared to sham CPAP treatment will result in improvements in energy balance, including increased physical activity, reductions in abnormally high levels of sleeping metabolic rate and circulating leptin levels, and reductions in hunger and food intake. These improvements are hypothesized to be associated with increases in the expression of REM sleep and SWS, and reduced EDS as a result of CPAP.
|Study Design:||Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Crossover Assignment
Masking: Single Blind (Subject)
Primary Purpose: Treatment
|Official Title:||Effects of CPAP on Energy Expenditure and Energy Intake in Obstructive Sleep Apnea|
- Energy expenditure [ Time Frame: After 2 months of treatment in both experimental phases ] [ Designated as safety issue: No ]Participants will remain in the whole-room indirect calorimetry chamber (metabolic chamber) for 23 hours during which time their total energy expenditure, as well as sleeping metabolic rate, and resting metabolic rate, will be measured.
- Ad libitum food intake [ Time Frame: After 2 months of treatment in both experimental phases ] [ Designated as safety issue: No ]Participants will be served meals (breakfast, lunch, dinner, snack) at specified times, but food will be served in excess such that participants will be able to eat as much as they want.
- Appetite-regulating hormones [ Time Frame: After 2 months of treatment in both experimental phases ] [ Designated as safety issue: No ]Blood will be sampled 1x/hour over 24 hours to assay levels of circulating hormones that regulate appetite and hunger, including leptin, ghrelin, adiponectin, and glucagon-like peptide-1
|Study Start Date:||November 2013|
|Estimated Primary Completion Date:||October 2016 (Final data collection date for primary outcome measure)|
Active Comparator: Active CPAP
Active CPAP will be a therapeutic dose of positive airway pressure each night for 2 months
Device: Active CPAP
Active CPAP will be a therapeutic dose CPAP each night for 2 months
Sham Comparator: Sham CPAP
Sham CPAP will be a sub-therapeutic dose of positive airway pressure each night for 2 months
Device: Sham CPAP
Other Name: Sham CPAP will be a sub-therapeutic dose of CPAP each night for 2 months
This study will be a randomized, placebo-controlled, crossover trial investigating the effects of 2 mo of active and sham continuous positive airway pressure (CPAP) on energy expenditure (EE) and energy intake (EI) in obese patients with moderate-to-severe obstructive sleep apnea (OSA) and excessive daytime sleepiness (EDS). Following pre-experimental baseline measures, patients (blinded to condition) will be instructed to use active or sham CPAP at home each night throughout the 2 mo treatment phases. After each 2 mo treatment phase, patients will undergo a 2-d in-lab testing period at the Clinical Research Resource (CRR) at St. Luke's-Roosevelt Hospital. Upon completion of the laboratory phase 1, patients will return home for a 1 mo washout period, followed by the second 2 mo treatment phase, including laboratory visit 2.
At the conclusion of the 2 mo treatment phase, patients will enter the laboratory at the CRR at St. Luke's-Roosevelt Hospital for a 2-d period. Patients will arrive at ~0800 h and will remain in the laboratory for the following 48 h. During the first 24 h, patients will remain in the whole-room indirect calorimetry chamber (metabolic chamber). During this time in the metabolic chamber, EE will be continuously monitored (total 24-h EE), including throughout the sleep episode (SMR), upon awakening in the fasted state (RMR), and after standard meals (postprandial EE). Blood will be sampled hourly for the 24-h period spanning the metabolic chamber recording period (day 1), and will be assayed for select appetite-regulating hormones (leptin, ghrelin, adiponectin, glucagon-like peptide-1).
During the laboratory day 1, standardized meals for a weight maintenance diet will be served at fixed time-points, including breakfast (0900 h), lunch (1300 h), snack (1600 h), and dinner (1900 h). Ad libitum EI will be measured during laboratory day 2 for each treatment phase. Breakfast, lunch, snack, and dinner will still be served at the standard times, but each meal item will be served in excess such that patients will be able to eat as much or as little of each food as they choose. Additional snack choices will also be freely available during the wake episode on laboratory day 2.
|Contact: Ari Shechter, Ph.D.||firstname.lastname@example.org|
|United States, New York|
|St. Luke's-Roosevelt Hospital||Not yet recruiting|
|New York, New York, United States, 10025|
|Contact: Ari Shechter, Ph.D. 212-523-1616 email@example.com|
|Principal Investigator: Ari Shechter, Ph.D.|
|Principal Investigator:||Ari Shechter, Ph.D.||New York Obesity Nutrition Research Center, St. Luke's-Roosevelt Hospital|