0414 Chronotype and Sleep Among Ovarian Cancer Survivors Participating in a Lifestyle Intervention

Abstract

Introduction: Chronotype is defined as an individual's propensity to sleep at a specific time in a 24‐hour cycle with late chronotype associated with poorer health outcomes including cancer. The role of chronotype on lifestyle behaviors remains relatively undefined in ovarian cancer. The Lifestyle Intervention for oVarian cancer Enhanced Survival study is testing whether 1205 women randomized to a diet and physical activity intervention for 24‐months will have longer progression‐free survival versus attention control. Here we determine the frequency and predictors of late versus early and mid chronotypes in disease‐free ovarian cancer survivors. Methods: 894 ovarian cancer survivors with baseline measures were included in analyses. Chronotypes were determined using self‐reported time to bed (early‐ < 9 pm; mid‐ ≥ 9 pm ‐ ≤12 am; late‐ >12 am) captured through the Pittsburgh Sleep Quality Index. Demographic, diet and physical activity data were captured with validated questionnaires and BMI measured in clinic. Descriptive statistics and logistic regression, adjusted for smoking status and race, were performed. Results: 12.4% of women were late chronotype with significant differences between chronotypes observed for race, smoking history, sleep duration, and physical activity (p < 0.05). Late chronotype reported fewer hours of sleep per night (6.54 ± 1.51hrs) compared to mid (7.10± 1.31hrs) and early (7.74 ± 1.30hrs) chronotype. Blacks had higher odds of being late chronotype, OR 4.28 (95% CI 2.16‐8.46). Late chronotype were more likely to report a history of smoking and lower recreational activity and had a higher mean BMI of 29.1± 6.0 kg/m2 compared to mid and early chronotype 27.8± 6.2 kg/m2 and 27.4± 5.4kg/m2, respectively. No significant differences were observed for sleep or diet quality, age, education or employment status. Conclusion: Results of this analysis are consistent with other community‐based population studies with regard to chronotype and race. Ovarian cancer is aggressive and late chronotype are more likely to have other risk factors that elevate risk of recurrence (obesity, tobacco use and inactivity. Six‐month data are being analyzed by treatment arm and will provide important insights as to the role of sleep phase and lifestyle behaviors in this vulnerable population.