To review the etiology of chronic fatigue syndrome (CFS) and test hypotheses relating to immune system dysfunction, physical deconditioning, exercise avoidance, and childhood illness experiences, using a large prospective birth cohort.
A total of 4779 participants from the Medical Research Council’s National Survey of Health and Development were prospectively followed for the first 53 years of their life with >20 separate data collections. Information was collected on childhood and parental health, atopic illness, levels of physical activity, fatigue, and participant’s weight and height at multiple time points. CFS was identified through self-report during a semistructured interview at age 53 years with additional case notes review.
Of 2983 participants assessed at age 53 years, 34 (1.1%, 95% Confidence Interval 0.8–1.5) reported a diagnosis of CFS. Those who reported CFS were no more likely to have suffered from childhood illness or atopy. Increased levels of exercise throughout childhood and early adult life and a lower body mass index were associated with an increased risk of later CFS. Participants who later reported CFS continued to exercise more frequently even after they began to experience early symptoms of fatigue.
Individuals who exercise frequently are more likely to report a diagnosis of CFS in later life. This may be due to the direct effects of this behavior or associated personality factors. Continuing to be active despite increasing fatigue may be a crucial step in the development of CFS.
CFS = chronic fatigue syndrome; BMI = body mass index.
From the Institute of Psychiatry (S.B.H., S.W., M.H.), King’s College London, London, UK; Medical Research Council’s National Survey of Health and Development (M.W.), Department of Epidemiology and Public Health, Royal Free and UCL Medical School, London, UK. M.W. is now retired.
Authors’ Contributions: M.H. and S.B.H. conceptualized and planned this study. M.W. coordinated the data collection and retrieval. S.B.H. and M.H. carried out the statistical analysis. S.B.H. wrote this paper with M.H., S.W., and M.W. providing detailed comments on early drafts.
Address correspondence and reprint requests to Samuel Harvey, Weston Education Centre, 10 Cutcombe Road, London, UK SE5 9RJ. E-mail: firstname.lastname@example.org
The Medical Research Council’s National Survey of Health and Development is funded by the Medical Research Council. M.H. and S.W. are partially funded by the South London and Maudsley NHS Foundation Trust/Institute of Psychiatry NIHR (National Institute of Health Research) Biomedical Research Centre.
Received for publication May 1, 2007; revision received November 12, 2007.