title: Relationship between energy expenditure, physical activity and weight loss during CPAP treatment in obese OSA subjects.
abstract: BACKGROUND
  Increased energy expenditure (EE) has been reported in patients with obstructive sleep apnea (OSA). It has been postulated that CPAP treatment may induce weight reduction in obese patients, even if it has not been confirmed by recent studies. In the present study we investigated the effect of OSA on EE and the effect of CPAP on body weight and physical activity.
  
  
  METHODS
  One hundred and seven obese OSA patients and 25 healthy obese volunteers, as control group, matched for age, sex and BMI, were enrolled. The following evaluation was performed only in OSA patients after 6 months of CPAP treatment.
  
  
  RESULTS
  Baseline total EE was similar in the two groups, but OSA patients showed higher EE during the night, while control group during daytime. In patients, EE correlates with OSA severity, degree of daytime sleepiness or obesity. At follow-up evaluation, BMI and total EE were unchanged. However, daytime EE increased (1066 ± 131.5 vs 1104 ± 133 Kcal/die, p < 0.001, respectively) and night EE decreased (694 ± 69 vs 595 ± 73, p < 0.0001, respectively). Statistically significant changes in BMI, sleepiness scale, blood gases and EE were found only in patients who were compliant to CPAP.
  
  
  CONCLUSIONS
  Obese OSA patients showed an increased night EE that was normalized only in those patients compliant to CPAP. Body weight and daily physical activity did not change in statistically significant way.
authors.affiliation: Respiratory Medicine "C. Cantù" Hospital, Piazza C.B. Mussi 1, 20081, Abbiategrasso, Milan, Italy.
authors.forename: Michele
authors.initials: M
authors.lastname: Bamberga
authors.affiliation: Respiratory Medicine "L. Sacco" Hospital University of Milan, Via G.B. Grassi 74, Milan, Italy.
authors.forename: Maurizio
authors.initials: M
authors.lastname: Rizzi
authors.affiliation: Sleep Center, Salvatore Maugeri Foundation IRCCS, Scientific Institute of Pavia, Italy.
authors.forename: Felice
authors.initials: F
authors.lastname: Gadaleta
authors.affiliation: Respiratory Medicine "C. Cantù" Hospital, Piazza C.B. Mussi 1, 20081, Abbiategrasso, Milan, Italy.
authors.forename: Attilio
authors.initials: A
authors.lastname: Grechi
authors.affiliation: Respiratory Medicine "C. Cantù" Hospital, Piazza C.B. Mussi 1, 20081, Abbiategrasso, Milan, Italy.
authors.forename: Renata
authors.initials: R
authors.lastname: Baiardini
authors.affiliation: Sleep Center, Salvatore Maugeri Foundation IRCCS, Scientific Institute of Pavia, Italy. Electronic address: francesco.fanfulla@fsm.it.
authors.forename: Francesco
authors.initials: F
authors.lastname: Fanfulla
mesh_terms: D001784:Blood Gas Analysis; D015992:Body Mass Index; D045422:Continuous Positive Airway Pressure / Q000379:methods*; D006970:Disorders of Excessive Somnolence / Q000175:diagnosis / Q000209:etiology; D004734:Energy Metabolism; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D007558:Italy; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D009765:Obesity / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology; D010349:Patient Compliance; D017286:Polysomnography / Q000379:methods; D012107:Research Design; D020181:Sleep Apnea, Obstructive / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy; D013223:Statistics as Topic; D015431:Weight Loss
keywords: CPAP; Energy expenditure; Obesity; Sleep; Sleep apnea; Sleepiness