Relationships among Physical Activity, Daylight Exposure, and Rest-Activity Circadian Rhythm in Patients with Esophageal and Gastric Cancer: An Exploratory Study

Background Although rest-activity circadian rhythm (RACR) disruption is associated with mortality in patients with cancer, few studies have examined the effect of RACR on patients with esophageal and gastric cancer. Objective The aim of this study was to identify the predictors of RACR. Methods This cross-sectional, single-site study included 276 patients with esophageal and gastric cancer recruited from chest-surgery and general-surgery outpatient departments. Actigraphy was used to assess objective physical activity (PA), daylight exposure, and RACR, and 3-day PA was used to indicate the subjective amount of PA. The parameter of objective PA was the up activity mean; the parameter of daylight exposure was >500 lx, and the parameters of RACR were the 24-hour correlation coefficient, in-bed less than out-of-bed dichotomy index, midline estimating statistic of rhythm, and amplitude. The subjective amount of PA was calculated as the sum of mild, moderate, and vigorous PA. Results The up activity mean predicted 24-hour correlation coefficient. The PA amount and up activity mean predicted in-bed less than out-of-bed dichotomy index. The up activity mean and >500-lx daylight exposure predicted midline estimating statistic of rhythm. Finally, the PA amount and up activity mean predicted the amplitude. Conclusions Increased PA and daylight exposure may improve RACR. Implications for Practice Patients with esophageal and gastric cancer should be encouraged to engage in outdoor PA during the daytime as part of their regular lifestyle to maintain a robust circadian rhythm.