Longitudinal associations between objective sleep and lipids: The CARDIA study

Study Objective: To investigate the longitudinal relationships between actigraph-derived sleep duration, fragmentation, and lipid levels. Design and Setting: Longitudinal data from the Coronary Artery Risk Development in Young Adults Sleep Study (2003-05), an observational cohort at the Chicago site. Participants: There were 503 black and white adults, ages 32-51 years, with no prior history of cardiovascular disease. Interventions: N/A. Measurement and Results: Sleep duration and fragmentation were measured using 6 days of wrist actigraphy. Sleep quality was measured with the Pittsburgh Sleep Quality Index. The outcome variables, measured at 3 examinations over 10 years (Baseline [2000-01], 5-year [2005-06], and 10-year follow-up [2010-11]), were total cholesterol (TC), high-density lipoprotein (HDL), low-density lipoprotein (LDL), triglycerides (TG), and TC/HDL ratio. The associations between each sleep parameter and 10-year change in lipids were analyzed with generalized estimating equation models adjusting for relevant confounders. After adjustment, each hour increase in sleep duration was significantly associated with higher TC (5.2 mg/dL, 95%CI: 1.7, 8.6) and LDL (3.4 mg/dL, 95%CI: 0.2, 6.6) in the total sample, a 1.1 mg/dL increase in TG (95%CI: 1.0, 1.1) among men, and a borderline significant greater odds for a TC/HDL ratio ≥ 5 among men (OR: 1.37, 95%CI: 0.99, 1.90). Overall, sleep fragmentation and sleep quality scores were not associated with change in lipids. Conclusions: Beyond relevant covariates, over a 10-year follow-up, longer objective sleep duration was longitudinally and significantly associated with a poorer lipid profile. Greater objective sleep fragmentation and self-reported poor sleep quality were not related to a poorer lipid profile.