Sex-specific Trends in Sleep Quality in Children and Adolescents

Hugi Hilmisson¹Solveig Magnusdottir^1*Robert J Thomas²

• ¹MyCardio LLC, Denver, United States
• ²Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, United States

IntroductionStrong developmental trends are well described in non-rapid eye movement sleep characteristics but also seen in cyclic-alternating-pattern (CAP). The latter shows a bimodal distribution: slow wave dominant (A1) complexes early in life and A2/A3 complexes later in life. This analysis aimed to assess trends in CAP-linked cardiopulmonary coupling (CPC) calculated Sleep Quality Index (SQI) from childhood through adolescence. Methods Analysis of de-identified data from the SleepImage System (MyCardio LLC, Denver, CO, USA), using CPC-calculations evaluating integrated electrocortical-autonomic-respiratory interactions to derive sleep states, SQI, and combined with oxygen saturation, an apnea hypopnea index (AHI). Results Forty-one thousand nights of continuous sleep recordings of  6-hours in duration and  4-hours of total sleep time (TST), with good signal quality (80%) from individuals <18-years of age were included in the analysis (48% girls-52% boys). Age groups were defined as 2-5 years (preschool-age, 39% girls-61% boys), 6-9 years (school-age, 47% girls-53% boys), 10-13 years (early-adolescent, 47% girls-53% boys), 14-17 years (late-adolescent, 52% girls-48% boys). In the cohort 20% had moderate- (AHI3% 5-10) and 8% severe sleep apnea (AHI3%10).SQI is highest in school-aged children that are expected to sleep for 9-12 hours/24-hours with no sex differences observed (75.815.8 and 75.316.2; p=0.06). Preschool-aged children are expected to sleep for 10-13 hours/24-hours, have a slightly lower SQI compared to school-aged children, with SQI higher in girls (73.417.5 and 71.619.2; p<0.001). During early adolescence, when sleep duration is expected to be 8-10hours/24-hours, SQI is significantly lower in girls compared to boys (70.517.4 and 71.817.0; p<0.001). In late adolescence, SQI decline continues, but at a slower rate in girls who, at this age, have higher SQI than boys (63.118.3 and 60.518.2). AHI3% is significantly lower in girls in all age-groups; it is lowest in school-age children and gradually increases during adolescence. ConclusionChildren seem to reach their full potential in sleep stability and quality around school-age. In early adolescence, measured sleep stability and quality start to gradually decline, with the decline starting earlier in girls while larger in boys during the adolescent years.