Sleeping Time Relates to Perceived Health and Psychoneuroimmunological Responses

The present study was to assess the relationship between sleeping time and the health of mind-body. Both subjective and objective outcome measurements such as General Health Questionnaire (GHQ)-28 and Psychoneuroimmunological (PNI) responses [3-methoxy-4-hydroxyphenylglychol(MHPG), immunoglobulin(Ig)-A] were used to assess the state of health and stress. Subjects were 205 healthy university students (110 males and 95 females). These subjects were divided by habitual sleeping time: adequate sleepers (AS) (6–8 hour sleep per night regularly) (n=35), short sleepers (SS) (less than 5 hour sleep per night regularly) (n=33) and long sleepers (LS) (more than 8 hour sleep per night regularly) (n=28). Subjects completed the questionnaire of GHQ-28 while the saliva samples were collected by chewing cotton swab, SALIVETTE, in the mouth during a lecture. Subscale scores of Social Dysfunction and Depression on GHQ-28 in LS were significantly higher than those in AS and SS. In addition to those, the scores of Somatic Symptoms on GHQ-28 in SS and LS were higher than AS. Levels of free-MHPG in SS were higher than those in LS, although free-MHPG levels in AS did not differ from SS and LS. The levels of s-IgA in SS were significantly lower than those in AS. The results of the logistic regression analysis indicated that both shorter sleep and longer sleep was associated with high scores of Somatic Symptoms, Social Dysfunction and Depression. These results demonstrated that sleeping time relates to perceived health and change in PNI function. Moreover, the results of PNI responses and GHQ-28 suggest that sleeping time is very important factor for prevention of stress disease and health promotion for university students.