1. Research content 1.1 Study on the Reliability and Validity of Daily Circadian Rhythm of Infant and Young Child Behavior and Establishment of Circadian Circadian Rhythm Prediction Model In three study communities, 10 infants aged 4 months, 6 months, 12 months and 2 years old were recruited, with a total of 120 infants. Daily rhythms of sleep, activity, illumination and eating were collected by using portable device Actiwatch-2 and daily log book. Saliva at 7 time points (09: 00, 13: 00, 17: 00, 21: 00, 01: 00, 05: 00 and 09: 00) were collected to determine the level of melatonin as the gold standard for circadian rhythm of biological clocks under natural environment. The correlation between daily circadian rhythms and characteristics of melatonin secretion was determined. A model with high reliability was established by mathematical modeling.
1.2 Multicenter Cohort Study of Effects of Sleep Intervention on Metabolic Function in Childhood Obesity Methods: A 1: 1 parallel multicenter randomized controlled trial was conducted to recruit 80 infants from each of the control group and the intervention group at 28 days after birth. The control group was followed up for 5 times (28 days, 2 months, 4 months, 6 months and 12 months) of evidence-based infant sleep intervention on the basis of routine child care, and followed up until 2 years old. The main outcomes were changes in BMI z at 0-6 months of age and metabolic markers of obesity at 2 years of age, such as BMI z, subcutaneous fat, body composition and blood biochemistry. On the basis of descriptive analysis, the effects of sleep intervention on infant obesity metabolism and daily rhythm were determined, and the causal mechanism of circadian rhythm, obesity metabolic index and other factors were determined by using Bayesian causal network.
1.3 Verification of Predictive Models for Circadian Rhythms of Behavioral Clocks In the second part of the three study communities, the two groups were randomly selected 20 cases, a total of 120 infants and children.
At 4 months, 6 months, 12 months and 2 years of age after birth, saliva samples were collected at 2 time points in addition to Actiwatch-2 and daily rhythm data, and melatonin levels were measured to validate the rhythm prediction model.
2. Research objectives
Based on the concept of early prevention, this project focuses on the role of circadian rhythms in infant sleep intervention to prevent obesity and accomplishes the following two objectives:
2.1 To determine the intensity of correlation between the daily rhythm of infants and the characteristics of melatonin secretion rhythm of gold standard.
Over mathematical modeling to establish high reliability and validity of behavioral biological clock circadian rhythm prediction model in infants and young children to verify and apply to sleep intervention multicenter cohort study.
2.2 To explore the effect of sleep intervention on infants by establishing a standard multicenter cohort of infant sleep intervention It is of great public health significance to provide high quality evidence for early prevention and control of childhood obesity and to design more pertinent prevention and control strategies.
