Sleep Quality and Quantity Affects Cardimetabolic Markers in Children Interview with:
Nina Berentzen
Centre for Nutrition, Prevention and Health Services
National Institute for Public Health and the Environment Bilthoven
The Netherlands What are the main findings of the study?

Answer: This study in 11-12 year old children shows that self-reported characteristics of sleep quality were not associated with blood pressure and HbA1c; and that in girls, but not in boys, some sleep characteristics were associated with anthropometric outcomes (BMI, waist circumference) and cholesterol levels. More specifically, in girls, longer time in bed was associated with lower BMI and waist circumference; having night-time awakenings with higher total cholesterol, going late to bed while rising early with higher total and HDL cholesterol; and feeling sleepy/tired during daytime with lower HDL cholesterol and with higher total-to-HDL cholesterol ratio. We report new findings for daytime outcomes of sleep quality that were not studied before in relation to cardiometabolic risk; e.g. difficulty with getting up in the morning, feeling rested after waking, and feeling sleepy or tired during the day. Our study therefore offers insight not only in characteristics of sleep at night, but also in consequences of sleep during the day. Were any of the findings unexpected?

Answer: Previous studies in adults have shown that inadequate sleep is associated with risk of metabolic syndrome and type 2 diabetes, and with increased cardiometabolic risk factors including weight status, cholesterol, blood pressure and glucose metabolism. In the pediatric population some associations have been found with individual cardiometabolic markers but previous studies mainly focused on duration of sleep.  In our study we were able to assess multiple characteristics of sleep quality besides sleep duration, and despite finding some associations in girls, we found no indications of a consistent increased or decreased cardiovascular risk associated with any specific sleep quality characteristic. What should clinicians and patients take away from your report?

Answer: The associations that we found do not point in the direction of an increased or decreased cardiovascular risk. Therefore, we consider it premature to propose that improved sleep could reduce cardiovascular risk during childhood. What recommendations do you have for future research as a result of this study?

Answer: The majority of previous studies assessed sleep duration while other sleep parameters as in our study have been reported scarcely, especially daytime outcomes. It is therefore important for further studies to explore other sleep characteristics besides sleep duration, to gain insight into aspects of sleep most relevant to cardiometabolic risk. These studies should assess relations of sleep with multiple cardiometabolic outcomes and not overweight solely.


Time in bed, sleep quality and associations with cardiometabolic markers in children: the Prevention and Incidence of Asthma and Mite Allergy birth cohort study

Berentzen, N. E., Smit, H. A., Bekkers, M. B. M., Brunekreef, B., Koppelman, G. H., De Jongste, J. C., Kerkhof, M., Van Rossem, L. and Wijga, A. H. (2013), Time in bed, sleep quality and associations with cardiometabolic markers in children: the Prevention and Incidence of Asthma and Mite Allergy birth cohort study. Journal of Sleep Research. doi: 10.1111/jsr.12087

Last Updated on November 26, 2014 by Marie Benz MD FAAD