Normalizing effect of bright light therapy on temperature circadian rhythm in patients with eating disorders.
OBJECTIVE
Light and food are important synchronizers of circadian rhythmicity. In eating disorders, the circadian rhythms of food intake and temperature are abnormal.


METHODS
We analyzed the effect of the morning light application on the circadian rhythm of tympanic temperature and its association with hunger and mood changes in the sample of 25 female patients hospitalized with DSM-IV diagnosis of eating disorders (14 bulimia nervosa and 11 anorexia nervosa) and in 6 healthy women.


RESULTS
Light therapy reduced interindividual variability of the temperature acrophase, synchronized the temperature and hunger rhythms and showed an antidepressant effect on patients with eating disorders. Bright light therapy normalized the circadian rhythm of body temperature in both anorexic and bulimic patients: phase advanced rhythm was delayed and phase delayed rhythm was advanced. In contrast with anorexic patients, the majority of bulimic patients had normal temperature rhythm before the therapy and this rhythm was not changed by the therapy.


CONCLUSIONS
The light therapy normalized temperature circadian rhythm in patient with eating disorders. We hypothesize that the light therapy can also contribute to improvement of pathological eating pattern because of the functional connections between light and food entrained oscillators. The light may help to restore the irregular circadian rhythmicity induced by chaotic food intake.
Yamamotová
Anna
A
Department of Normal, Pathological and Clinical Physiology, 3rd Faculty of Medicine, Charles University, Prague, Czech Republic. yamamoto@lf3.cuni.cz
Papezová
Hana
H
Vevera
Jan
J
D000328:Adult; D000339:Affect / Q000502:physiology; D000856:Anorexia Nervosa / Q000503:physiopathology* / Q000523:psychology / Q000628:therapy*; D001066:Appetite / Q000502:physiology; D001831:Body Temperature / Q000502:physiology*; D052018:Bulimia Nervosa / Q000503:physiopathology* / Q000523:psychology / Q000628:therapy*; D002940:Circadian Rhythm / Q000502:physiology*; D004435:Eating / Q000502:physiology; D005260:Female; D006801:Humans; D006815:Hunger / Q000502:physiology; D010789:Phototherapy / Q000379:methods*