Etiology of CFS

Etiology of Chronic Fatigue Syndrome: Testing Popular Hypotheses
Using a National Birth Cohort Study.

Journal: Psychosom Med. 2008 Mar 31 [Epub ahead of print]

Authors: Harvey SB, Wadsworth M, Wessely S, Hotopf M.

Affiliations: 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.

PMID: 18378866


Objective: 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.

Methods: 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.

Results: 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.

Conclusions: 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.

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This is something we've said for years: those of us who are Type A personalities dragged ourselves out of bed the first day we felt a little better and tried to go back to our normal life before we were truly well.  In 1987, I went back to work the day after I was first able to sit propped up with pillows for an hour.  With no car, "going back to work" required me to walk about 6 blocks uphill from the bus stop to the office, and about 4 blocks from the bus stop to home.  A pretty stringent exercise regimen for someone who's not yet over a serious illness.  Maybe if I had waited another week or two to get back my strength before I undertook that much exercise on a daily basis, I might not have CFS in the first place.  But I had work to do, and I was out of sick days, so I went, never dreaming that the virus I had was not just a particularly nasty case of stomach flu.  As a dancer, I was used to pushing through exhaustion, and that discipline was likely my downfall.

The question that will always be asked -- and never answered -- is, if I had taken a week off in January 2000 to get well instead of dragging myself to work even as I got sicker, would I have wound up in this years-long relapse?  In retrospect, I suspect that giving in and taking to my bed for a week may have been a better decision than continuing to "do the responsible thing" and go to work.

As time went on, I could no longer walk the 2 miles to work and had to take the bus.  At the end, even the 4 blocks from the bus stop to my desk was so exhausting that I had to rest for an hour before I did anything.  Medically, it is impossible to decondition that far that fast; the problem is not, as some doctors have postulated, "deconditioning" but the effects of a virus exhausting the body's resources until the patient collapses.