Associations between morning–evening chronotype, fatigue, and QOL in breast cancer survivors.

Abstract

246 Background: Emerging evidence suggests that circadian disruption is associated with cancer and cancer treatments. Chronotype is defined as a behaviorally manifested preference for a certain timing of sleep and activity. Previous studies have revealed that living out of sync from one’s innate chronotype can have detrimental effects on one’s health. Although there has been research examining the associations between chronotype and health, not much is known about the relationship between chronotype, fatigue, and QOL in cancer survivors. Methods: 68 Breast cancer survivors completed questionnaires to assess their chronotype (Horne-Ostberg), to rate their fatigue (MDASI), and to evaluate their QOL (FACIT). The Horne-Ostberg questionnaire yields a range of values indicating survivors’ preference for early or late activity. The study sample was divided by terciles according to survivors’ “morningness” or “eveningness” preferences (i.e., chronotypes). Results: Morning chronotype was associated with significantly less severe tiredness and drowsiness as well as significantly better physical well-being and fatigue subscale scores as compared to evening chronotype. Tiredness median (M) scores were highest for evening chronotype (M=5.5), moderate for mid-range chronotype (M=4.5), and lowest for morning chronotype (M=3.0), a significant difference (p=0.046). Drowsiness scores were highest for evening chronotype (median=6.0), moderate for mid-range chronotype (M=4.0), and lowest for morning chronotype (M=3.0), p=0.046. The median score for physical well-being was significantly lower for evening compared to morning chronotypes (22.5 vs. 25.0, p=0.038) and morning types reported significantly better health in respect to fatigue compared to evening types (40.5 vs. 35.5, p=0.045). Conclusions: Survivors with early chronotype (early to bed, early to rise) reported less fatigue, drowsiness, and better overall physical well-being. While chronotype is believed to be genetically driven, certain behavioral, pharmacological, and bright light modifications can be used to help patients shift their circadian rhythm towards earlier morning type and may experience improvements in physical well-being.

Do posttraumatic stress symptoms predict trajectories of sleep disturbance and fatigue in patients with breast cancer? A parallel‐process latent growth model

“…It should also be noted that the late chronotype was associated with a higher initial SD, which resulted in a faster increase in fatigue. Previous studies have observed bivariate associations of chronotypes with SD and fatigue 26 . However, a study with 458 (non‐) Hodgkin lymphoma survivors observed no significant association between chronotype and fatigue but observed a significant association between subjective sleep quality and daily dysfunction and fatigue 25 .…”

“…Last, the conditional parallel‐process LGM with baseline PTSS (i.e., avoidance, intrusion, and hyperarousal) as predictors was examined. Anxiety, depressive symptoms, and chronotype were entered as covariates in the research model given the association of anxiety with sleep 23 and fatigue 24 and that of depression 23 with SD and fatigue 1 and that of chronotype with sleep 25 and fatigue 26 …”

“…Previous studies have observed bivariate associations of chronotypes with SD and fatigue. 26 However, a study with 458 (non-) Hodgkin lymphoma survivors observed no significant association between chronotype and fatigue but observed a significant association between subjective sleep quality and daily dysfunction and fatigue. 25 Current findings on the indirect effect of chronotype on the course of fatigue through SD extend the understanding of these previous findings.…”

“…Anxiety, depressive symptoms, and chronotype were entered as covariates in the research model given the association of anxiety with sleep 23 and fatigue 24 and that of depression 23 with SD and fatigue 1 and that of chronotype with sleep 25 and fatigue. 26 To examine the statistical significance of indirect effects in the conditional parallel-process LGM, bias-corrected 95% confidence intervals (CIs) were estimated using 5000 bootstrapping. The indirect effect is significant when the CI does not include 0.…”