Obesity Research & Clinical Practice (2008) 2, 251—262 ORIGINAL ARTICLE Weight reduction improves sleep, sleepiness and metabolic status in obese sleep apnoea patients Pia Nerfeldt a,* , Bengt Y. Nilsson b , Liliana Mayor b , Joanna Uddén c , Stephan Rössner c , Danielle Friberg a a Department of Clinical Science, Intervention and Technology, Division of Ear, Nose and Throat Diseases, Karolinska Institute, Karolinska University Hospital-Huddinge, SE-141 86, Stockholm, Sweden b Department of Clinical Neuroscience, Division of Clinical Neurophysiology, Karolinska Institute, Karolinska University Hospital-Huddinge, SE-141 86, Stockholm, Sweden c Department of Medicine, Huddinge, Division of Endocrinology, Karolinska Institute, Karolinska University Hospital-Huddinge, SE-141 86, Stockholm, Sweden Received 22 August 2008; accepted 24 August 2008 KEYWORDS Sleep apnoea; Obstructive sleep apnoea; Sleep disorders; Sleepiness; Sleep quality; Sleep architecture; Sleep state; Sleep pattern; Arousal index; Obesity; Weight loss; Weight reduction; Diet; Nocturnal respiration; Polysomnography; Summary Method: In this prospective intervention study, 33 obese patients with obstructive sleep apnoea syndrome (OSAS) (24 men, 9 women) were consecutively enrolled for a weight reduction program at the Obesity Unit, Karolinska University Hospital. 23 of 33 patients used OSAS-device, 19 with Continuous Positive Airway Pressure and 4 with Mandibular Retaining Device. The patients were investigated with questionnaires, blood tests and ambulant nocturnal polysomnography before and after a 6-month program. Patients with OSAS-device slept without it during the sleep studies. The intervention consisted of 8 weeks low calorie diet and group meetings, followed by a day-care program of behaviour change support. Results: 27 of 33 patients (82%, 21 men and 6 women) completed the study. After the intervention there were highly significant decreases (p < 0.001) in Body Mass Index from mean(S.D.) 40(5) to 34(3), apnoea—hypopnoea index from 43(24) to 26(20) and Epworth Sleepiness Scale (ESS)-score from 9(4) to 6(4). Sleep qual- ity (arousal index, sleep efficiency, percentage deep sleep) and metabolic status (blood pressure, blood glucose levels, lipidemia) were also significantly improved. There was a significant correlation between increased percentage deep sleep and reduced ESS-score. There were no differences due to gender or use/no use of OSAS-device. ∗ Corresponding author at: Karolinska University Hospital-Huddinge, ORL-dept B53, SE-141 86 Stockholm, Sweden. Tel.: +46 8 58580000; fax: +46 8 7467551. E-mail address: pia.nerfeldt@karolinska.se (P. Nerfeldt). 1871-403X/$ — see front matter © 2008 Asian Oceanian Association for the Study of Obesity. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.orcp.2008.08.001