Relationship between energy expenditure, physical activity and weight loss during CPAP treatment in obese OSA subjects - 11/03/15

Doi : 10.1016/j.rmed.2015.02.010

Michele Bamberga ^a, Maurizio Rizzi ^b, Felice Gadaleta ^c, Attilio Grechi ^a, Renata Baiardini ^a, Francesco Fanfulla ^c,^⁎
^a Respiratory Medicine “C. Cantù” Hospital, Piazza C.B. Mussi 1, 20081, Abbiategrasso, Milan, Italy
^b Respiratory Medicine “L. Sacco” Hospital University of Milan, Via G.B. Grassi 74, Milan, Italy
^c Sleep Center, Salvatore Maugeri Foundation IRCCS, Scientific Institute of Pavia, Italy

^∗Corresponding author. Sleep Center, Salvatore Maugeri Foundation, Scientific Institute of Pavia IRCCS, Via Maugeri 10, 27100, Pavia, Italy. Tel.: +39 0382 592807; fax: +39 0382 592024.

Sous presse. Épreuves corrigées par l'auteur. Disponible en ligne depuis le Wednesday 11 March 2015

Summary

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.

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Keywords : Sleep apnea, Obesity, Energy expenditure, CPAP, Sleep, Sleepiness