Longitudinal Analysis of Sleep Duration and Cardiometabolic Risk in Young Children

Background: To determine if sleep duration in early childhood is associated with cardiometabolic risk in later childhood as assessed by a cardiometabolic risk (CMR) cluster score (sum of age and sex-standardized z-scores of waist circumference (WC), systolic blood pressure (SBP), triglycerides, glucose, and (inverse) high density lipoprotein (HDL)). Secondary objectives included examining sleep duration and the individual cardiometabolic risk factors and BMI z-score. Methods: A prospective cohort study was conducted using data from the TARGet Kids! practice-based research network in Toronto, Canada. Children (n=597) with parent reported 24-hour sleep duration in early childhood (12-36 months) and a follow-up visit (36-96 months) with all five CMR factors were included in the analysis. Multivariable linear regression was used to assess the relationship between early childhood sleep duration and later childhood cardiometabolic risk, adjusting for relevant covariates. Results: Average 24-hour sleep duration in early childhood [mean age: 28.1 (6.6) months] was 11.8 (1.4) hours, with 87% meeting or exceeding total sleep recommendations for their age. Sleep duration in early childhood was not associated with the CMR cluster score in later childhood. Shorter sleep duration was associated with higher HDL concentrations [adjusted Beta = -0.028 (95% CI: -0.049, -0.007), p=0.009]. Conclusions: Further research is needed to determine if early childhood sleep duration is associated with HDL in later childhood. Future studies, which investigate sleep quality in addition to sleep duration, may be helpful.We thank all of the participating families for their time and involvement in TARGet Kids! and are grateful to all practitioners who are currently involved in the TARGet Kids! practice-based research network. Advisory Committee: Eddy Lau, Andreas Laupacis, Patricia C. Parkin, Michael Salter, Peter Szatmari, Shannon Weir. Research Team: Charmaine Camacho, Arthana Chandraraj, Dharma Dalwadi, Ayesha Islam, Thivia Jegathesan, Tarandeep Malhi, Megan Smith, Laurie Thompson. Applied Health Research Centre: Christopher Allen, Bryan Boodhoo, Judith Hall, Peter Juni, Gerald Lebovic, Karen Pope, Jodi Shim, Kevin Thorpe; Mount Sinai Services Laboratory: Azar Azad