Determinants and impact of sleep duration in children and adolescents: data of the Kiel Obesity Prevention Study

Abstract

Background/Objectives: This study investigates determinants of sleep duration and its impact on nutritional status, resting energy expenditure (REE), cardiometabolic risk factors and hormones in children/adolescents. Subjects/Methods: In 207 girls and 207 boys (13.0±3.4 (6.1-19.9) years) body mass index standard deviation score (BMI SDS), waist circumference (WC) z-score, body composition (air-displacement plethysmography), REE (ventilated hood system; n ¼ 312) and cardiometabolic risk factors/hormones (n ¼ 250) were assessed. Greater than 90th percentile of BMI/WC references was defined as overweight/overwaist. Sleep duration, media consumption (TV watching/computer use), physical activity, dietary habits, parental BMI, socio-economic status and early infancy were assessed by questionnaire. Short sleep was defined as o10 h per day for children o10 years and otherwise o9 h per day. Results: Total 15.9% participants were overweight, mean sleep duration was 8.9±1.3 h per day. Age explained most variance in sleep (girls: 57.0%; boys: 41.2%) besides a high nutrition quality score (girls: 0.9%) and a low media consumption (boys: 1.3%). Sleep was inversely associated with BMI SDS/WC z-score (girls: r ¼ À0.17/À0.19, Po0.05; boys: r ¼ À0.21/À0.20, Po0.01), which was strengthened after adjusting for confounders. Short vs long sleep was associated with 5.5-/2.3-fold higher risks for obesity/overwaist (girls). After adjusting for age, REE (adjusted for fat-free mass) was positively associated with sleep in boys (r ¼ 0.16, Po0.05). Independently of age and WC z-score, short sleep was associated with lower adiponectin levels in boys (11.7 vs 14.4 mg/ml, Po0.05); leptin levels were inversely related to sleep in girls (r ¼ À0.23, Po0.05). Homoeostasis model assessment-insulin resistance (r ¼ À0.20, Po0.05) and insulin levels (r ¼ À0.20, Po0.05) were associated with sleep (girls), which depended on WC z-score. Conclusions: Age mostly determined sleep. Short sleep was related to a higher BMI SDS/WC z-score (girls/boys), a lower REE (boys), higher leptin (girls) and lower adiponectin levels (boys).

Health behaviors, waist circumference and waist-to-height ratio in children

“…This can be due to a small statistical power or the fact that meal patterns, TV viewing and food habits, which all have been associated with sleep duration (Ray et al, 2007;Hitze et al, 2009;Westerlund et al, 2009) were mediators of this association. In two other studies, sleep duration has been related to larger WC, but mostly only among girls Hitze et al, 2009). In many recent studies, shorter sleep duration has been found to be associated with overweight in children (Patel and Hu, 2008).…”

“…The presence of a TV in a child's bedroom was found to be associated with larger WC and other obesity measures, but only in boys (Delmas et al, 2007). Shorter sleep duration was related to larger WC, at least in girls in two studies Hitze et al, 2009). Only few studies have reported results on food habits and WC in children.…”

Sleep duration and body-weight development during puberty in a Dutch children cohort

“…For instance, children with short sleep duration show decreases in leptin concentrations, decreased insulin sensitivity and altered cortisol concentrations, all promoting lipogenesis. 15,51,52 Thus, changes in hypothalamic functioning, such as altered hypocretin-1 signaling may explain the relationship between the changes in BMI and in sleep duration during puberty, via altered puberty onset, energy balance regulation and circadian rhythm. As food-entrainment in addition to light-entrainment, functions as a 'Zeitgeber' of the circadian rhythm, possibly alterations in dietary patterns may also explain the relationship between BMI and sleep duration.…”

Duração do sono em adolescentes de diferentes níveis socioeconômicos

“…Na puberdade, pode ser identificado um atraso de fase, caracterizado por horários tardios de dormir e acordar que, somados aos horários sociais e de início das aulas pela manhã, levam a uma importante diminuição das horas de sono [12][13][14] . Por conseguinte, uma duração inadequada de sono está associada a um aumento da sonolência diurna, dificuldades de aprendizagem, diminuição da qualidade de vida e maiores prevalências de doenças como a obesidade 7,15,16 .…”