1 Submitted: 7 May, 2019; Revised: 1 September, 2019 © Sleep Research Society 2019. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com. Original Article Obesity and other medical comorbidities among NT1 patients after the Norwegian H1N1 infuenza epidemic and vaccination campaign Sebjørg E. H. Nordstrand 1,2, *, Hilde T. Juvodden 1,2 , Rannveig Viste 1,2 , Terje Rootwelt 2,3 , Tor-Ivar Karlsen 4 , Per M. Thorsby 5 , David Swanson 6 , Kristian Bernhard Nilsen 7 , Berit H. Hansen 1 and Stine Knudsen-Heier 1 1 Department of Rare Disorders, Division of Paediatric and Adolescent Medicine, Norwegian Centre of Expertise for Neurodevelopmental Disorders and Hypersomnias (NevSom), Oslo University Hospital, Norway, 2 Faculty of Medicine, University of Oslo, Norway, 3 Department of Paediatrics, Oslo University Hospital, Norway, 4 Faculty of Health and Sports Sciences, University of Agder, Norway, 5 Hormone Laboratory, Department of Medical Biochemistry, Oslo University Hospital, Aker, Norway, 6 Oslo Centre for Biostatistics and Epidemiology, Oslo University Hospital, Norway and 7 Department of Neurology, Section for Clinical Neurophysiology, Oslo University Hospital, Norway *Corresponding author. Sebjørg Hesla Nordstrand, Norwegian Centre of Expertise for Neurodevelopmental Disorders and Hypersomnias, P.B. 4956, Nydalen, 0424 Oslo, Norway. Email: sebnor@ous-hf. Abstract Study Objectives: Narcolepsy type 1 (NT1) may be complicated by comorbidities. We aimed to study the extent of obesity and other medical comorbidities in a Norwegian population of NT1 patients with debut of symptoms after the 2009 H1N1 infuenza epidemic and vaccination campaign. We also aimed to explore factors associated with obesity. Methods: Ninety-one patients (48 children and 43 adults) were included in this cross-sectional study, 80 of whom were H1N1-vaccinated. All participants were hospitalized and underwent sleep investigation and physical examination, and completed a semi-structured clinical interview. Results: In children, 16 females (70%) and 10 males (40%) were classifed as overweight or obese. Twenty children (42%) had a co-existing medical disorder. Medical comorbidity was signifcantly positively associated with BMI in children (p = .032). In adults, 19 females (58%) and 7 males (70%) were classifed as overweight or obese. Twenty-six adults (61%) had a co-existing medical disorder. We found no factors signifcantly associated with BMI in adults. On a fatigue scale from 0 to 100, lower scores indicating more fatigue, we found a mean (SD) total fatigue score of 50 (17) in children and 39 (16) in adults. Conclusion: In a cohort of predominantly H1N1-vaccinated NT1 patients, we found a high prevalence of overweight or obesity. Half of the cohort presented with one or more additional medical comorbidities, and patients reported a clinically relevant degree of fatigue. Our fndings highlight the importance of carefully monitoring patients with NT1 with regard to the development of obesity, which is a signifcant risk factor for cardiovascular disorders. Key words: narcolepsy; H1N1 vaccination; obesity; comorbidity; fatigue Statement of Signifcance Narcolepsy is complicated with a high prevalence of comorbidities, obesity in particular. However, it is poorly understood why some pa- tients are at more risk of developing obesity than others. We found a high prevalence of obesity in patients who developed narcolepsy type-1 (NT1) after the H1N1 vaccination campaign. Medical comorbidity in children, but not in adults, was the only factor signifcantly as- sociated with obesity, indicating that the development of obesity is not dependent on the age of onset or severity of narcolepsy. Finally, we found severe fatigue both in children and adults. Our study emphasizes the importance of monitoring patients with NT1 in regard to the development of obesity, which is a signifcant risk factor for secondary medical complications and decreased quality of life. SLEEPJ, 2020, 1–8 doi: 10.1093/sleep/zsz277 Advance Access Publication Date: 14 November 2019 Original Article Downloaded from https://academic.oup.com/sleep/article/43/5/zsz277/5625549 by guest on 27 January 2022