Associations Of Sleep Duration With Overweight,obesity,and Metabolic Syndrome In Children And Adolescents

BackgroundRecently,with a rapid decline in the sleep duration of children and adolescents worldwide,insufficient sleep among children and adolescents has become an important public health problem.According to the 2010-2012 China Health and Nutrition Survey(CHNS),the average daily sleep duration of children and adolescents aged 6-17 years is 8.45 hours,and the detection rate of short sleep duration is 69.8%.Cumulating evidence suggests that short sleep duration is associated with increased risks of obesity,metabolic syndrome(MetS),and other cardiovascular events in adults.However,there is limited studies exploring the associations of short sleep duration with overweight/obesity and MetS in children and adolescents,and the results have been inconsistent.From 1985 to 2014,the prevalence of overweight in Chinese school-aged children increased from 2.1%to 12.2%,while the prevalence of obesity increased from 0.5%to 7.3%.It is expected that by 2030,if effective intervention measures were not adopted,the prevalence of overweight and obesity among children and adolescents would reach 28.0%.A meta-analysis of 11 studies showed that shorter sleep duration was associated with an increased risk of childhood obesity(OR=1.58,95%CI=1.26?1.98).However,some studies suggest that sleep duration has a U-shaped non-linear relationship with childhood obesity.Wu et al.found that the prevalence of obesity in Chinese middle school and high school students was the lowest when they slept for 7-8 hours,and the prevalence of obesity was higher when they slept for more or less than this period.The rapid increase in the population of obese children has led to an increase in the prevalence of MetS around the world.MetS is a complex clustering of metabolic disorders,which includes abdominal obesity,hypertension,hyperglycemia,high triglycerides(TG),and low high-density lipoprotein(HDL-C).Data from 2010-2012 CHNS showed that the prevalence of MetS among Chinese children and adolescents aged 10-17 years was 4.3%(Cook Criteria).A cross-sectional study of 3,843 Iran children aged 7-18 years found that,compared with subjects whose sleep duration>8 hours,those whose sleep duration?8 hours was associated with an increased risk of MetS(OR=2.05,95%CI=1.19?3.63).However,a cross-sectional analysis of 133 American obese children aged 10-16 years showed that sleep duration was not associated with MetS,regardless of subjectively or objectively measured sleep indicators.Today,few studies have investigated the associations of sleep duration with overweight,obesity,and MetS among Chinese children and adolescents.Childhood,as a key period for the development of growth,metabolism and behavioral patterns,is a window and sensitive period for early prevention of many adult diseases.In the current social context of widespread sleep deprivation in children and adolescents,assessing the potential risks of short sleep duration on overweight,obesity,and MetS in children and adolescents,will facilitate determining the public health implications of sleep in the field of childhood cardiovascular disease prevention and control.Objectives1.To investigate the relationships of sleep duration with overweight and obesity in children and adolescents,and explore the sex differences in these associations.2.To investigate the relationships of sleep duration with MetS and its components among children and adolescents,and explore the sex differences in these associations.Subjects and methods1.Study populationThe data based on the Jinan branch center of Twelfth Five-year National Science and Technology Support Program-"Early warning,diagnosis and treatment of cardiovascular disease in children",which was conducted in 4 public non-boarding schools(2 primary schools,1 junior high school,and 1 high school)in Jinan city from 2012 to 2014,using the convenient cluster sampling method.Subjects are children and adolescents aged 6-17 years who have participated voluntarily,and have a household registration in Jinan or have lived in Jinan for more than one year.A total of 7,840 students were investigated.Among them,6,145 participants had complete sleep duration and anthropometric measurements,and 1,065 participants had complete sleep duration,anthropometric measurements,and blood biochemical indicators.2.MeasurementsQuestionnaires,anthropometric measurements,and blood biochemical test were conducted.The questionnaire data included information on sex,age,sleep duration,high-sugar diet,paternal educational level,and maternal educational level.Anthropometric measurements indicators included height,weight,waist circumference(WC),systolic blood pressure(SBP),and diastolic blood pressure(DBP).Blood biochemical indicators included fasting blood glucose(FPG),TG,and HDL-C.3.DefinitionAccording to the "A Consensus Statement of the American Academy of Sleep Medicine" in 2016,children aged 6-12 years and adolescents 13-18 years are recommended to sleep 9-12 hours and 8-10 hours per day,respectively.Short sleep duration was defined as less than the recommended sleep duration,and adequate sleep referred to meeting the recommended sleep duration.Because the number of people whose sleep duration above the recommended sleep duration was very small,20 participants who had long sleep duration were excluded from the original database.Overweight and obesity were defined by using the "Screening for Overweight and Obesity of School-aged Children and Adolescents" issued by the National Health and Family Planning Commission of the People's Republic of China in 2018.MetS was defined according to the adapted definition in children and adolescents by Cook et al.in 2003 based on the American Cholesterol Education Program-Adult Treatment Panel ?(NCEP-ATP?)criteria in adults for MetS(Cook Criteria).4.Statistical analysisThe software of SAS 9.4 was used for data analysis,and two-sided P value<0.05 was considered to be statistically significant.Continuous variables were described as mean ± standard deviation(x±s),and one-way analysis of variance was used to assess differences in different groups.Categorical variables were described as percentage(%),and differences in different groups were assessed using Chi-squared test.Multiple Linear regression model was used to analyze the association between sleep duration and BMI among children and adolescents,after adjustment for sex,age,high-sugar diet,paternal educational level,and maternal educational level,and sex-subgroup analysis was conducted.Multinomial Logistic regression model was conducted to analyze the relationships of short sleep duration with overweight and obesity in children and adolescents,after adjustment for sex,age,high-sugar diet,paternal educational level,and maternal educational level,and subgroup analysis was performed by sex.Binary Logistic regression model was used to analyze the relationship between short sleep duration and MetS in children and adolescents,after adjustment for sex and age,and subgroup analysis was conducted by sex.Restricted cubic spline(RCS)model was used to analyze the dose-response relationship between sleep duration and the risk of overweight,obesity and MetS in children and adolescents.Results1.Relationships of sleep duration with overweight and obesity in children and adolescentsAmong 6,145 children and adolescents,41.0%had short sleep duration,and the prevalence of overweight and obesity was 17.8%and 20.8%,respectively.In Multiple Linear regression analysis,the results showed that sleep duration was negatively associated with BMI in children and adolescents.With an hour increase of sleep duration,the overall BMI decreased by 0.22 kg/m2(?=-0.22,95%CI=-0.34?-0.09).In the subgroup analysis,with an hour increase of sleep duration,the BMI decreased by 0.26 kg/m2(?=-0.26,95%CI=-0.46?-0.07)and 0.18 kg/m2(?=-0.18,95%CI=-0.34?-0.01)among boys and girls,respectively.In Multinomial Logistic regression analysis,short sleep duration was associated with an increased risk of obesity(OR=1.18,95%CI=1.02-1.36),but not associated with overweight(OR=1.10,95%CI=0.94?1.28),after adjustment for sex,age,high-sugar diet,paternal educational level,and maternal educational level.In the subgroup analysis,the associations of short sleep duration with overweight and obesity(all P<0.05)were found only in boys,but not in girls.Using RCS analysis,after controlling for sex,age,high-sugar diet,paternal educational level,and maternal educational level,the results showed a linear dose-response relationship between sleep duration and the risk of overweight and obesity(nonlinear test,all P>0.05).2.Relationship between sleep duration and MetS in children and adolescentsIn 1,065 children and adolescents,the prevalence of MetS was 10.7%.Binary Logistic regression analysis showed that compared with adequate sleep,short sleep duration was associated with the increased risk of MetS(OR=1.84,95%CI=1.1 6-2.90)in children and adolescents,after adjustment for sex and age.In addition,short sleep duration in children and adolescents was also associated with the increased risk of abdominal obesity,elevated blood pressure(BP),and high TG(all P<0.05),but not with the risk of high FPG and low HDL-C.In subgroup analyses,short sleep duration was associated with MetS(OR=2.05,95%CI=1.21-3.49)only in boys,while no association was found among girls.Among boys,short sleep duration was associated with the increased risk of abdominal obesity,elevated BP and high TG(all P<0.05).The significant association between short sleep duration and abdominal obesity was found in girls.Using RCS analysis,after adjustment for sex and age,the results showed a linear dose-response relationship between sleep duration and the risk of MetS(nonlinear test,P=0.328).Conclusions1.Short sleep duration was associated with an increased risk of obesity in children and adolescents.Sleep duration was negatively correlated with BMI,and had a linear dose-response relationship with the risk of overweight and obesity.2.Short sleep duration was associated with an increased risk of MetS among children and adolescents,as well as with the risk of abdominal obesity,elevated BP,and high TG.Sleep duration had a linear dose-response relationship with the risk of MetS.3.Among boys,short sleep duration was associated with the increased risk of overweight,obesity,and MetS,while no such association was found among girls.