0699 CIRCADIAN ACTIVITY RHYTHMS AND SLEEP AMONG CHINESE COLLEGE STUDENTS

Abstract

Sleep problems are prevalent for young adults. For college students, sleep disturbances could be associated with their stress derived from school works or daily life. Circadian activity rhythms (CAR) have been found to be altered among dementia, cancer patients, and distressed postpartum women. To date, studies exploring CAR in healthy adults are rare. The study aimed to: 1) describe the characteristics of CAR, and 2) explore the associations between CAR and stress and stress-related symptoms in college students. Impaired Sleep Model was used to guide for this descriptive correlational study. A total of 26 (12 males, 14 females) college students completed this study. A battery of questionnaires was used during the week after midterm examination to assess stress and stress-related symptoms (sleep disturbances, fatigue, physical symptoms). One-week consecutive wrist actigraphy data, including total sleep time (TST) and wake after sleep onset (WASO) were collected. Cosinor analysis was used for computing the CAR, including mesor, acrophase (time of the peak of the fitted activity curve), and amplitude. The mean age for the students was 21.04 (SD= .92) and in average they need about 8 hours of sleep to feel refreshed; however, the actual nocturnal TST (M= 396.7 minutes, SEM= 12.57) was significantly less then what they needed (paired t[25]= -3.7, p= .001). They perceived moderate stress, reported a clinically significant fatigue severity, and half of them experienced at least two physical symptoms. The CAR was desynchronized (M= .63, SEM= .03) and WASO was 7.2% (SEM=.7). The average peak activity level was at 17:18 indicates delayed sleep phase syndrome. A trend was seen between poor CAR and poor daytime functioning and more physical symptoms. After control for gender, CAR along with perceived stress explained 64% of variance in nocturnal total sleep time. Results showed that college student’s sleep and CAR were disturbed, and they also experienced distress and fatigue. It appears that CAR plays a role in stress-related symptoms. Educational materials in the areas of sleep hygiene and mind-body exercise to regulate CAR should be mandatorily included in the college education.