Social Jetlag And Cardiometabolic Disease Risk In Pre- Adolescents

Abstract

PURPOSE: Social jetlag (SJL), the inconsistency between an individual’s circadian clock and social clock, has been associated with cardiometabolic diseases (CMD) in adults. In pre-adolescents, SJL has been associated with overweight-obesity, but no previous studies have examined associations with CMD risk. The objective of the current study was to determine the associations between sleep duration, sleep disturbances and SJL with CMD risk among preadolescent children. METHODS: This cross-sectional study recruited 392 children (50% F) aged 8-10 years from three representative sample sites across New Zealand. Three sleep quality variables were measured: Sleep duration, as reported by caregivers for seven days; sleep disturbances, estimated by the Children’s Sleep Habits Questionnaire; and SJL, measured as the absolute difference between midpoints of sleep on weekdays versus weekend days. Eleven CMD risk factors were measured: central and peripheral systolic blood pressure (BP), heart rate, augmentation index, diastolic BP, low density lipoprotein levels, high density lipoprotein levels, total cholesterol, triglycerides, fasting blood glucose, and glycated hemoglobin. Factor analysis identified underlying CMD risk factors. Linear regression models determined the associations between the sleep variables and the CMD risk factors. Models were adjusted for age, sex, and socio-economic status. Effects sizes (ES) were calculated by dividing the beta coefficient (β) by the standard deviation of β, where <0.20 was considered small, > 0.20 to < 0.50 moderate, and > 0.80 large. RESULTS: Complete data was available for 332 children (49% F, mean [SD] age = 9.6 [1.13] years old, WHO-BMI = 0.421 [1.17]). Factor analysis revealed four underlying CMD risk factors: blood pressure, cholesterol, vascular health, and carbohydrate-metabolism. Following adjustment for covariates, there was a small association between SJL and the cholesterol factor (P=0.025, ES=0.11), and a small association between SJL and the carbohydrate-metabolism factor (P=0.027, ES=0.10). In fully-adjusted multivariate models, sleep duration nor sleep disturbances associated with any CMD factor. CONCLUSIONS: Social jetlag is a modifiable and potentially important contributor to cardiometabolic risk in children.