Core body temperature is normal in chronic fatigue syndrome.
BACKGROUND
Subjects with chronic fatigue syndrome (CFS) frequently report symptoms of subnormal body temperature and low-grade fever. We conducted a study to determine whether CFS subjects manifest any abnormality of core body temperature (CBT) that might help explain their fatigue.


METHODS
Continuous 24-hour recordings of CBT measured every 5 min were performed in 7 subjects meeting the Centers for Disease Control definition of CFS. Three additional groups were studied: normal controls, subjects with seasonal allergy, and subjects with major depression. Subjects (n = 7) in each group were age-, sex-, and weight-matched to the CFS group and had normal basal metabolic rates, thyroid function, and 24-hour urinary free cortisol excretions. CBT was measured with an ingestible radio frequency transmitter pill and a belt-worn receiver-logger. Each pill was factory-calibrated to +/- 0.1 degree C and field-calibrated with a water bath calibration prior to use.


RESULTS
The 24-hour mean calibration-adjusted CBTs of each group were not significantly different (control: 37.00 +/- 0.17 degrees C; CFS: 37.04 +/- 0.31 degrees C; allergy: 37.15 +/- 0.18 degrees C; depression: 37.16 +/- 0.18 degrees C). Similarly, the mean peak and trough circadian temperatures were not statistically different. The mean 24-hour profile of CBT for each group showed a similar circadian rhythm. In simultaneously collected blood samples, each group showed a similar circadian profile of serum cortisol with a peak occurring at 08:00.


CONCLUSIONS
Subjects with CFS have normal CBT despite frequent self-reports of subnormal body temperature and low-grade fever.
Hamilos
D L
DL
National Jewish Center for Immunology and Respiratory Medicine, Denver, Colorado, USA.
Nutter
D
D
Gershtenson
J
J
Redmond
D P
DP
Clementi
J D
JD
Schmaling
K B
KB
Make
B J
BJ
Jones
J F
JF
D000328:Adult; D001831:Body Temperature / Q000502:physiology*; D002940:Circadian Rhythm / Q000502:physiology; D003866:Depressive Disorder / Q000503:physiopathology; D015444:Exercise / Q000502:physiology; D015673:Fatigue Syndrome, Chronic / Q000503:physiopathology*; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D006967:Hypersensitivity / Q000503:physiopathology; D007074:Immunoglobulin G / Q000276:immunology; D008297:Male; D008875:Middle Aged; D018670:Monitoring, Ambulatory; D013686:Telemetry
D007074:Immunoglobulin G; D006854:Hydrocortisone