Abstract 20971: Associations Between Objectively Measured Sleep Duration and 10-Year Predicted Cardiovascular Risk in Older Adult Women

Abstract

Introduction: In the US, 90% of women are living with one or more CVD risk factors, such as: high total cholesterol or hypertension, or lifestyle behaviors such as physical inactivity. Emerging evidence supports sleep duration, both short and long, as a potential modifiable lifestyle factor associated with CVD. Research on sleep duration and CVD risk is, however, limited by use of self-report sleep measures, homogeneous populations, and studies on individual CVD risk factors. Hypothesis: We examined the relationship between objectively measured sleep duration and predicted CVD risk, estimated by Reynolds Risk Score (RRS). We hypothesized that short sleep (<6 hours) and long sleep (>8 hours) would be associated with higher RRS compared to 6-8 hours. Methods: Cross-sectional data were analyzed in 1,316 racial/ethnically diverse older women, from the Objective Physical Activity and Cardiovascular Health Study, ancillary study to the Women’s Health Initiative. Women wore ActiGraph GT3X+ accelerometers on the hip for 24 hours over 7 days and completed a daily sleep log. RRS was calculated using data on age, sex, smoking, diabetes, hypertension, and high-sensitivity to CRP. Daily sleep duration was derived from accelerometer data. Adjusted linear regression models estimated the association of sleep duration and RRS. Participants were categorized as short (<6), healthy (6-8), and long sleepers (>8hrs/day) to account for non-linear associations with RRS. Adjusted means across categories were calculated using least-squares means procedure. Results: Results suggest a U-shaped relationship between sleep duration and RRS, with both short and long sleepers having significantly increased RRS compared to healthy sleepers (both comparisons p<0.01), with adjustments for BMI and race/ethnicity. Short and long sleepers had mean RRS of 15.7% and 13.6% respectively, compared to 11.2% among healthy sleepers. Results remained significant after further adjustments for education, self-rated health, and alcohol use. Conclusions: In older women, when compared to healthy sleep, actigraphy-ascertained short and long sleep durations are associated with increased 10-year estimated CVD risk, independent of adjustment for race/ethnicity, BMI, and known covariates.