0826 Chronotype, unhealthy lifestyle, and diabetes risk in middle-aged US women: A prospective cohort study in Nurses’ Health Study II

Abstract Introduction Chronotype refers to one’s inclination earlier or later sleeping times. Late chronotype has been linked increased diabetes risk, which may be mediated through adherence unhealthy lifestyle. This study aimed evaluate the interplay among chronotype, lifestyle factors, and risk. Methods In 2009, 63,594 diabetes-free women (mean age=54 yrs) from Nurses’ Health Study II self-reported their using a validated question Morningness-Eveningness Questionnaire were prospectively followed for incident type 2 (T2DM) until June 2017. Unhealthy was defined by having < 4 of following 6 healthy factors: high diet quality (AHEI≥49), physical activity (≥3.5 MET-hours/week), moderate alcohol intake (≥5 15 g/day), normal body mass index (≥18.5 25 kg/m2), non-current smoking, 7-9 hours sleep. T2DM confirmed supplementary questionnaire. We used modified Poisson regression models estimate cross-sectional associations between Cox proportional hazards adjusted hazard ratios (aHR) risk according assess proportion association explained factors (mediation analyses). Results Participants reporting “definitely-evening” 55% (95% CI: 1.51-1.60) more likely have an compared with participants “definitely-morning” type. documented 1,921 cases over 468,555 person-years follow-up. With increasing eveningness, became significantly higher (Ptrend< 0.0001). Compared type, aHR CI) 1.10 (0.97-1.24) “more-morning”, 1.01 (0.81-1.27) “intermediate”, 1.26 (1.11-1.42) “more-evening”, 1.65 (1.44-1.90) chronotypes, after adjusting sociodemographic shift-work, depression family history diabetes. Additional adjustment 56.8% 39.4%-72.6%) [aHR versus “definitely-morning”: 1.27 (1.10-1.46)]. Conclusion Women late are engage in behaviors. is associated partly Our results suggest that interventions potentially reduce adverse impact on Support (if any) R01HL155395, K01HL143034, U01CA176726