Are symptoms of insomnia related to respiratory symptoms? Cross-sectional results from 10 European countries and Australia

• Published in: BMJ Open
• Main Authors: Bjornsdottir, Erla, Lindberg, Eva, Benediktsdottir, Bryndis, Gislason, Thorarinn, Garcia Larsen, Vanessa, Franklin, Karl, Jarvis, Debbie, Demoly, Pascal, Perret, Jennifer L, Garcia Aymerich, Judith, Arenas, Sandra Dorado, Heinrich, Joachim, Torén, Kjell, Jögi, Rain, Janson, Christer
• Other Authors: Ministère de la Santé. Programme Hospitalier de Recherche Clinique (PHRC, Medical Research Council UK, The Swiss National Science Foundation, ResMed Foundation, The Swedish Heart and Lung Foundation, Norges Forskningsråd, Fondo de Investigación Sanitaria, The Swedish Asthma and Allergy Association, The Swedish Association against Lung and Heart Disease.Fondo de Investigación Sanitaria, German Research Foundation, Deutsche Forschungsgemeinschaft, Agence Nationale de la Santé, The Icelandic Research fund, Estonian Ministry of Education, National Health & Medical Research Council Australia, The Landspitali University Hospital Research Fund, University of Iceland Research Fund, by Cariverona foundation, Education Ministry (MIUR)., Italian Ministry of Health, Research Foundation Flanders (FWO), European Commission, Comite Scientifique AGIRadom, INSERM U897 Université Bordeaux segalen
• Format: Article in Journal/Newspaper
• Language: English
• Published: BMJ 2020
• Subjects: Iceland
• Online Access: http://dx.doi.org/10.1136/bmjopen-2019-032511; https://syndication.highwire.org/content/doi/10.1136/bmjopen-2019-032511

Objectives To compare the prevalence of different insomnia subtypes among middle-aged adults from Europe and Australia and to explore the cross-sectional relationship between insomnia subtypes, respiratory symptoms and lung function. Design Cross-sectional population-based, multicentre cohort study. Setting 23 centres in 10 European countries and Australia. Methods We included 5800 participants in the third follow-up of the European Community Respiratory Health Survey III (ECRHS III) who answered three questions on insomnia symptoms: difficulties falling asleep (initial insomnia), waking up often during the night (middle insomnia) and waking up early in the morning and not being able to fall back asleep (late insomnia). They also answered questions on smoking, general health and chronic diseases and had the following lung function measurements: forced expiratory volume in 1 s (FEV 1 ), forced vital capacity (FVC) and the FEV 1 /FVC ratio. Changes in lung function since ECRHS I about 20 years earlier were also analysed. Main outcome measures Prevalence of insomnia subtypes and relationship to respiratory symptoms and function. Results Overall, middle insomnia (31.2%) was the most common subtype followed by late insomnia (14.2%) and initial insomnia (11.2%). The highest reported prevalence of middle insomnia was found in Iceland (37.2%) and the lowest in Australia (22.7%), while the prevalence of initial and late insomnia was highest in Spain (16.0% and 19.7%, respectively) and lowest in Denmark (4.6% and 9.2%, respectively). All subtypes of insomnia were associated with significantly higher reported prevalence of respiratory symptoms. Only isolated initial insomnia was associated with lower FEV 1 , whereas no association was found between insomnia and low FEV 1 /FVC ratio or decline in lung function. Conclusion There is considerable geographical variation in the prevalence of insomnia symptoms. Middle insomnia is most common especially in Iceland. Initial and late insomnia are most common in Spain. All insomnia ...