Relationship Between Clustering Of Metabolic Risk Factors And Left Ventricular Hypertrophy In Children

1 BackgroundWith the rapid development of the economy and the increase of unhealthy lifestyles,the prevalence of abdominal obesity,glucose and lipid metabolism disorder,and high blood pressure is increasing in children and adolescents.Metabolic syndrome(MetS)in children were defined as having abdominal obesity and suffering from at least two of the following risk factors:high blood sugar,high blood pressure,low high-density lipoprotein cholesterol(HDL-C),and high triglycerides(TG).The monitoring of nutrition and health status of residents from 2010 to 2012 showed that the prevalence of MetS in children and adolescents aged 10-17 years was 2.4%(95%CI:21%～2.6%)in China.MetS,obesity,high blood pressure,glucose and lipid metabolism disorder are important risk factors for cardiovascular disease(CVD)in adults.Although CVD is an uncommon disease in children,the persistent effects of multiple CVD risk factors can cause damage to target organs such as heart,blood vessels and kidneys,thereby increasing the risk of CVD lin adulthood.Left ventricular hypertrophy(LVH)is one of the important indicators to evaluate early cardiac structural damage.To explore the relationship between the clustering of metabolic risk factors(abdominal obesity,high blood sugar,high blood pressure,low HDL-C and high TG)and LVH and to identify early cardiovascular risk factors has important public health significance for preventing and controlling of LVH in children.However,there are few studies focusing on the clustering of metabolic risk factors and LVH in children.This study recruited 1416 children from a primary school in Zibo City to explore the relationship between the clustering of metabolic risk factors and LVH in children,and provide a scientific evidence for early warning of cardiac structural damage in children2 Objectives(1)To explore the relationship between MetS and its components and LVH in children.(2)To explore the relationship between the clustering of metabolic risk factors and LVH in children.3 Subjects and methods3.1 SubjectsData was obtained from the baseline survey of"Zibo Huantai Cardiovascular Health Cohort in children",supported by the National Natural Science Foundation of China,which was belongs to the project of G"Building Early Warning Indicator System for Cardiovascular Disease Based on Target Organ Damages".This project was performed in a primary school in Huantai County,Zibo City with cluster sampling and convenient sampling method.The students from 1st grade to 5th grade in this school who voluntarily participated and obtained the informed consent from their guardians were selected.The survey was conducted from November 2017 to January 2018.A total of 1516 children aged 6-11 years participated in the questionnaire survey,body measurement,blood biochemical analysis or ultrasonography examinations.A total of 1416 children(750 boys)had complete indicators.3.2 Data collectionThe questionnaire was used to collect basic information,including parental smoking or drinking,family history of chronic diseases(including hypertension.diabetes,stroke,heart disease,etc.).Waist circumference(WC),height,weight and blood pressure were collected by body measurement.The fasting plasma glucose(FPG)and blood lipids were collected by blood biochemical analysis.The left ventricular mass(LVM)was collected by ultrasound examination and the left ventricular mass index(LVMI)was calculated.The clustering definition of metabolic risk factors was determined by the five MetS components of abdominal obesity,high blood sugar,high blood pressure,low HDL-C and high TG,and then divided into 4 groups according to the number of metabolic risk factors:0 component,1 component,2 components,and≥3 components.3.3 Statistical analysisStatistical analysis was performed using SAS 9.4 software.Differences in categorical variables were compared by chi-square test.Differences in continuous variables were compared by t-test and the general linear model.The metabolic indicators were converted to standard Z scores and the ROC curve analysis was used to analyze the standardized metabolic indicators to predict the area under the curve(AUC)of LVH in children.The multivariate linear regression model was used to analyze the trend of left ventricular mass index with the clustering of metabolic risk factors after adjusting for sex and age.The binary logistic regression model was used to analyze the trend of LVH with the clustering of metabolic risk factors after adjusting for sex and age.The relationship between MetS and its components,the clustering of MetS components and LVH in children were analyzed by binary logistic regression model after adjusting for sex and age.The odds ratio(OR)and 95%confidence interval(95%CI)were calculated.In the sensitivity analysis,extra adjusting parental smoking and drinking,chronic diseases(including hypertension,diabetes,stroke,heart disease,etc.),binary logistic regression model was used to analyze the effects of MetS and its components,the clustering of MetS components on LVH in children.LVMI)sex and age-specific P95 was defined as LVH,and LVMI)sex and age-specific P90 was used to perform sensitivity analysis.Bilateral P<0.05 indicates statistical significance.4 Results4.1 LVMI level and LVH detection rate in the group of MetS and its components and the clustering of metabolic risk factorsA total of 1416 children were included in the study,including 750 boys,accounting for 53%of the total.The age ranged from 6 to 11 years old with an average age of 8.4± 1.5 years.ROC curve analysis showed BMI and WC predicted that children’s LUH had higher AUC than other metabolic indicators,and the difference was statistically significant(P<0.001).The levels of LVMI in children with MetS,abdominal obesity,high blood sugar,high blood pressure,low HDL-C,and high TG were significantly higher than those in the control group after adjusting for sex and age(P<0.001).The detection rate of LVH in children with MetS,abdominal obesity,high blood pressure,low HDL-C and high TG was higher than that of the control group,and the difference was statistically significant(P<0.001).With the clustering of metabolic risk factors,the level of LVMI and the detection rate of LVH showed upward trends((P<0.001),after adjusting for sex and age.4.2 Relationship between MetS and its components,the clustering of metabolic risk factors and LVH in childrenMetS,abdominal obesity,high blood pressure,and abnormal lipid metabolism were associated with LVH in children.The OR values of LVH in children with MetS,abdominal obesity,high blood glucose,high blood pressure,low HDL-C and high TG were 4.6(95%CI:2.4～9.0),10.5(95%CI:6.1～18.0),and 0.7(95%CI:0.3～2.1),and 1.9(95%CI:1.1～3.3),2.3(95%CI:1.4～3.9)and 4.3(95%CI:2.4～7.9),respectively,after adjusting for sex and age.Abdominal obesity has the greater impact on children with LVH.The effect of high blood glucose on LVH in children was not statistically significant.Clustering of metabolic risk factors was associated with increased damage to the heart structure ofchildren.With 0 components as the reference,the(OR value of LVH in one component was 3.4(95%CI:1.7～7.0),two components was 11.1(95%CI:5.5～22.4)and)3 components was 12.2(95%CI:5.3～28.1),respectively.4.3 Sensitivity analysis of relationship between MetS and its components,the clustering of metabolic risk factors and LVH in childrenFurther adjusting for parents’smoking,drinking status,chronic diseases(including hypertension,diabetes,stroke,heart disease,etc.),the results were similar.MetS,abdominal obesity,high blood pressure,low HDL-C and high TG were all associated with LVH in children.The effect of high blood glucose on LVH in children was not statistically significant.The effect of clustering of metabolic risk factors on children’s LVH increased(P<0.001).In addition,LVMI)sex and age-specific 90th percentile was used to judge children’s LVIH,and the relationship between MetS and its components,the clustering of metabolic risk factors and LVH in children were similar.MetS,abdominal obesity,high blood pressure,low HDL-C and high TG were all associated with LVH in children.The effect of high blood glucose on LVH in children was not statistically significant.The effect of clustering of metabolic risk factors on children’s LVH increased(P<0.001).5 conclusion(1)MetS,abdominal obesity,high blood pressure,and abnormal lipid metabolism were associated with LVH in children.Abdominal obesity had a greater effect on LVH in children.High blood sugar may have no effect on children’s LVH.(2)With the clustering of metabolic risk factors,the level of LVMI and the detection rate of LVH showed upward trends.(3)Clustering of metabolic risk factors increased the risk of LVH in children.