Original Research ARTICLE
Aging and the change in fatigue and sleep – a longitudinal study across 8 years in three age groups
- 1Clinical Neuroscience, Karolinska Institute (KI), Sweden
- 2Stress Research Institute, Stockholm University, Sweden
- 3Department of Environmental Medicine, Karolinska Institute (KI), Sweden
- 4Psychology Clinic, Karolinska University Hospital, Sweden
- 5Stress Research Instiute, Stockholm University, Sweden
Fatigue is prevalent in the population and usually linked to sleep problems, and both are related to age. However, previous studies have been cross sectional. The purpose of the present study was to investigate the trajectories of sleep and fatigue across 8 years of aging in a large group (N>8.000) of individuals. A second purpose was to investigate whether fatigue trajectories would differ between age groups, and whether different trajectories of fatigue would be reflected in a corresponding difference in trajectories for sleep variables. Results from mixed model analyses showed that fatigue decreased across 8 years in all age groups, while sleep problems increased, non-restorative sleep decreased, weekend sleep duration decreased, and weekday sleep duration showed different patterns depending on age. Furthermore, the larger the decrease in fatigue, the larger was the increase in sleep duration across years, the lower was the increase of sleep problems, and the larger was the decrease of non-restorative sleep. The results suggest that aging has positive effects on fatigue and sleep and that these changes are linked.Introduction
Keywords: sleep duration, sleep quality, Non-restorative sleep, mixed models, trajectories
Received: 25 Nov 2017;
Accepted: 12 Feb 2018.
Edited by:Philippe Peigneux, Université libre de Bruxelles, Belgium
Reviewed by:Herbert Heuer, Leibniz Research Centre for Working Environment and Human Factors (LG), Germany
Konstantin G. Arbeev, Duke University, United States
Copyright: © 2018 Åkerstedt, Discacciati, Miley-Åkerstedt and Westerlund. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Dr. Torbjörn Åkerstedt, Karolinska Institute (KI), Clinical Neuroscience, Solna, 17177, Sweden, Torbjorn.Akerstedt@ki.se