Relationships of Circadian Rhythms and Physical Activity With Objective Sleep Parameters in Lung Cancer Patients

BACKGROUND: Lung cancer patients undergo various treatments leading to sleep problems, rest-activity circadian rhythms disruption, and reduced levels of physical activity. It is important to understand the relationships among these variables. Appropriate interventions can possibly be implemented to improve sleep quality in lung cancer patients. OBJECTIVE: The objective of this study was to examine the relationships of circadian rhythms and physical activity with objective sleep parameters in 106 of Taiwanese lung cancer patients. METHODS: This study used a cross-sectional design. The instruments included an actigraph to measure the objective sleep parameters (total sleep time TST, sleep efficiency, and sleep-onset latency SOL), rest-activity circadian rhythms (r24 24-hour autocorrelation coefficient and I < O in-bed less than out-of-bed dichotomy index), and physical activity frequency (UP activity mean). The daily physical activity amount in minutes was measured by the Bouchard 3-day physical activity record. RESULTS: Patients performing light-intensity physical activity of 295 min/d or greater had better values for the TST, sleep efficiency, SOL, r24, and I < O than those performing less than 295 min/d (all P < .05). Significant predictors of the TST included age (β = -.31), I < O (β = .32), and UP activity mean (β = -.42). Predictors of the SOL included current treatment (β = .20), I < O (β = -.28), UP activity mean (β = .51), and 24-hour light-activity minutes (β = -.23). CONCLUSIONS: Marked circadian rhythms and adequate light-intensity physical activity may improve sleep quality in lung cancer patients. IMPLICATIONS FOR PRACTICE: Adequate light-intensity physical activity can be an effective intervention to improve sleep quality in lung cancer patients.