Abstract MP20: Evening Chronotype is Associated With Poor Cardiovascular Health and Adverse Health Behaviors in a Diverse Population of Women

Abstract

Background: Chronotype is the behavioral manifestation of an individual’s innate circadian rhythm. Evening chronotype (i.e. being a “night owl”) is linked to elevated chronic disease and mortality risk in European and Asian populations. Evidence from US cohorts is limited, particularly among women, in whom evening chronotype prevalence becomes higher from midlife onward, coinciding with life stages and hormonal changes associated with higher cardiovascular disease (CVD) risk. Hypothesis: Being a definite evening chronotype would be associated with poor cardiovascular health (CVH) and elevated cardiometabolic risk factors. Methods: Participants were 506 diverse women (mean age=37±16y, 62% racial/ethnic minority) in the AHA Go Red for Women Strategically Focused Research Network at Columbia University. Chronotype was measured using the Morningness-Eveningness Questionnaire (MEQ), the most widely used validated tool by circadian biologists to ascertain chronotype. Higher scores reflected greater morningness. Participants were also categorized as “evening” vs. “intermediate/morning” chronotypes based on their MEQ scores. Health behaviors (diet, physical activity, sleep, and sedentary time) were assessed using validated questionnaires. Health factors (BMI, blood pressure, fasting glucose, and cholesterol) were assessed at the clinic visit. Overall CVH was evaluated using the AHA Life’s Simple 7 (LS7) score (0-8: poor, 9-14: moderate to high). Linear and logistic regression models adjusted for age, race/ethnicity, education, health insurance, and menopause were used to examine associations of chronotype with CVH, clinical risk factors, and health behaviors. Results: Overall, 13% of women identified as being evening chronotypes. Higher MEQ scores (i.e. greater morningness) were associated with higher AHA LS7 scores (β=0.02, p=0.01), indicative of more favorable CVH. Higher MEQ scores were also associated with having a lower Pittsburgh Sleep Quality Index, i.e. better sleep quality, (β=-0.07, p<0.0001), a lower Insomnia Severity Index (β=-0.14, p<0.0001), shorter time to fall asleep (β=-0.28, p=0.04), and less sedentary time (β=-0.11, p=0.001). In contrast, being an evening chronotype was associated with higher odds of poor CVH (OR (95%CI): 2.41 (1.20-4.85)), not meeting AHA diet (OR (95%CI): 2.89 (1.59-5.23)) and physical activity guidelines, (OR (95%CI): 1.78 (1.03-3.07)), and having short sleep (<7h) (OR (95%CI): 2.15 (1.24-3.73)) or insomnia symptoms (OR (95%CI): 2.69 (1.53-4.75)). Conclusions: Women with evening chronotypes have greater odds of having poor CVH and adverse health behaviors after adjustment for sociodemographic factors and menopausal status. Chronotype may be important to consider and target in lifestyle interventions aimed at CVD prevention, particularly among middle-aged and older women who are prone to sleep changes.