Energy expenditure in obstructive sleep apnea. effects of treatment
with continuous positive airway pressure.
Stenlsf, K., R. Grunstein, J. Hedner, L. Sjsstrsm.
Departments of Medicine and Clinical Pharmacology Sahlgrenska
University Hospital, Gsteborg, Sweden, Sleep Disorders Centre, Royal
Prince Alfred Hospital, Sydney, Australia
APStracts 3:0146E, 1996.
We examined 24 h energy expenditure (24hEE) in a chamber for indirect
calorimetry in five male patients with obstructive sleep apnea (OSA)
and six snoring control subjects (Snorers). 24 h EE was remeasured in
patients with OSA after three months treatment with nasal continuous
positive airway pressure (CPAP). Patients with OSA had a greater
degree of severe sleep-breathing disturbance than snorers. Patients
with OSA had higher 24h EE (39.2+/-3.0 vs 33.9+/-2.7 kcal.24h
-1.kgFFM-1, p<0.05), daytime urinary norepinephrine,
vanylmandelic acid (VMA) and aminoterminal procollagen III peptide
(pIIIp) levels and tended to have higher sleeping EE (32.4+/-4.1 vs
26.3+/-1.9 kcal.24h-1.kgFFM-1, p<0.1) than snorers. CPAP
treatment normalised sleep architecture and breathing. CPAP treatment
also decreased sleep EE (from 32.4+/-4.1 to 27.2+/-1.4 kcal.24h
-1.kgFFM-1, p<0.05), EE variability during sleep (from 1.6+/-0.5
to 1.0+/-0.5 kcal.24h-1.kgFFM-1, p<0.05) and increased the
BMR/Sleep EE ratio in all subjects. Serum pIIIp and plasma
norepinephrine decreased after CPAP in all patients. We conclude that
OSA is associated with an increased sleep EE which is normalised by
treatment with CPAP.
Received 16 January 1996; accepted in final form 15 July 1996.
APS Manuscript Number E19-6.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 25 July 1996