1016 SLEEP-WAKE TIMING AND STABILITY ARE ASSOCIATED WITH INCREASED BLOOD PRESSURE IN THE SUEÑO ANCILLARY STUDY OF THE HISPANIC COMMUNITY HEALTH STUDY/STUDY OF LATINOS (HCHS/SOL)

Abstract

Introduction: In addition to sleep duration there is growing evidence that the timing and variability of the sleep-wake cycle may also be important modifiable cardiometabolic disease risk factors. We aim to evaluate the relationship between objective actigraphy-based measures of sleep-wake timing and stability with cardiometabolic disease risk. Methods: Using actigraphy to record daily rest-activity patterns for seven days, data regarding sleep-wake timing and stability were obtained from 2156 participants aged 18-64 years in the Sueño ancillary study of the Hispanic Community Health Study/Study of Latinos (HCHS/SOL). Measurements of cardiometabolic disease risk (systolic (SBP) and diastolic blood pressure (DBP), fasting levels of glucose and insulin, and insulin resistance) were assessed at the baseline HCHS/SOL visit (2008-2011) while body mass index (BMI) and hypertension diagnosis were determined during the ancillary study visit (2010-2013). Associations were examined using survey linear regression, adjusting for age, gender, background, site, income, acculturation and sleep duration. Results: Decreased day-to-day stability in sleep habits, as measured by the interdaily stability index, is associated with greater risk for a diagnosis of hypertension (-0.355, p<0.01), as well as higher measured SBP (-7.825, p<0.05) and DBP (-8.018, p<0.05). In addition, later sleep timing, as measured by sleep midpoint is associated with higher SBP (0.733, p<0.01) and DBP (0.534, p<0.01). These associations remained present after adjusting for age, gender, background, site, income, acculturation, and sleep duration. There is no association between sleep timing or interdaily stability and BMI, insulin resistance or diabetes. Conclusion: Later sleep midpoint and decreased day-to-day stability in sleep are associated with higher systolic and diastolic blood pressure. These data suggest that additional characteristics of sleep, beyond sleep duration, are important risk factors for cardiovascular health.