Abstract P201: Inverse Association between Sleep Efficiency and Cholesterol Fractions in African Americans; the Cardiovascular Health Epidemiology Study
Background: Previous studies have shown that African Americans (AA) have lower sleep efficiency than Caucasians. Less is known in AA regarding the effect of sleep efficiency on metabolic markers of cardiovascular disease such as serum levels of cholesterol fractions. Thus, we conducted a cross-sectional investigation among AA examining the relationship between sleep duration and efficiency with cholesterol levels. Our hypothesis was that there is an inverse association between the duration and efficiency of sleep and cholesterol fractions.
Methods: Our study population (n = 35; 60% women) was recruited throughout metro Atlanta via convenience sampling with radio announcements, flyers and health fairs. Included were AA aged 30-65 with a blood pressure lower than 140/90 mm Hg. Total cholesterol (TC), high-density lipoprotein cholesterol (HDL-cholesterol) and their ratio was measured as continuous variables. Sleep efficiency was measured with an Actiwatch device as the proportion of actual sleep time to the total amount of bedtime sleep. Multivariable linear regression models were used to examine the effects of sleep efficiency and duration on TC, HDL-cholesterol and their ratio with adjustments for age and body mass index (BMI). Statistical significance was set at a p-value of <0.05 (two-tailed).
Results: Among study participants, the mean (SD) was 52.3 (9.0) years for age, 31.6 (6.6) kg/m2 for BMI, 79.0 (7.5)% for sleep efficiency and 7.03 (1.3) hours for sleep duration. The mean (SD) was 195.5 (31.2) mg/dL for TC, 98.7 (31.2) mg/dL for triglycerides, 62.2 (17.9) mg/dL for HDL-cholesterol and 3.33 (0.83) for the ratio TC / HDL. Sleep efficiency correlated significantly with sleep duration (r = 0.36) and TC / HDL-cholesterol ratio (r = -0.32), but not with BMI or triglycerides. In the multivariable regression analysis, there was a statistically significant inverse association between sleep efficiency and the ratio of TC / HDL cholesterol (β = - 0.05, 95% confidence Interval = - 0.09, - 0.01; p = 0.008). No association was detected between sleep duration and cholesterol fractions (p = 0.90).
Conclusion: Among African Americans, there is an inverse association between sleep efficiency and the ratio of TC to HDL-cholesterol. Reduced sleep efficiency might influence the cardiovascular risk through dyslipidemia.
- © 2013 by American Heart Association, Inc.