%0 Journal Article
%T A possible connection between psychosomatic symptoms and daily rhythmicity in growth hormone secretion in healthy Japanese students
%A Mitsuo Nagane
%A Kazunori Yoshimura
%A Shu-Ichi Watanabe
%A Masahiko Nomura
%J Journal of Circadian Rhythms
%D 2009
%I BioMed Central
%R 10.1186/1740-3391-7-10
%X We examined 15 healthy students (4 men and 11 women) between 21 and 22 years old. To assess the presence of psychosomatic symptoms among the subjects, we developed a self-assessment psychosomatic complaints questionnaire consisting of five items pertaining to physical symptoms and five items concerning mental symptoms. The subjects rated their psychosomatic symptoms twice a day (08:00 and 20:00 h). We also assessed growth hormone secretion patterns by fluorescence enzyme immunoassay (FEIA). Salivary samples were collected from the subjects at home five times a day (20:00, 24:00, 04:00, 08:00, and 12:00 h) in Salivette tubes.The results indicated a relationship between the self-assessment scores and the salivary levels of growth hormone. Subjects with high self-assessment scores showed significant variability in growth hormone secretion over the day, whereas subjects with low self-assessment scores did not.Psychosomatic symptoms may be associated with circadian dysfunction, as inferred from blunted rhythmicity in growth hormone secretion.Japanese students suffering from psychosomatic disorders, such as those involving mood and sleep, may exhibit basic problems in their lifestyle, including deleterious changes in their living environment and dietary or lifestyle disturbances [1]. In particular, staying up late is associated with decreased appetite and missed breakfast the following morning, irregular bowel movements and sleepiness. Perhaps the biggest problem facing today's Japanese students is their lack of daily physical exercise, brought on by stressful academic courses over long periods of time, too much television and computer games and increased automobile use [2]. Many Japanese youngsters stay up late at night [3].A circadian pacemaker in the central nervous system regulates human sleep cycles, hormone secretion, subject alertness, objective performance levels and other physiologic functions over a 24-h period. Core body temperature, plasma cortisol, and plasma
%U http://www.jcircadianrhythms.com/content/7/1/10