Prevalence Of Elevated Blood Pressure And Target Organ Damage In Children And Adolescents Aged 6-17 Years In Urban Area Of Jinan

BackgroundIn recent years,due to the development of social economy and changes of living lifestyles,chronic non-communicable diseases(NCDS),including hypertension(HTN),has become a serious public health issue in China.Currently,the prevalence of hypertension in adults is about 28%and the number of adults with hypertension is about 270 million.Along with adult hypertension having not yet been effectively controlled,the problem of elevated blood pressure(EBP)in children has also become increasingly prominent.As indicated by the China Health and Nutrition Survey,the prevalence of EBP in school-aged children aged 6-17 years increased from 7.6%in 1993 to 13.8%in 2009.In 2010,the National Student Physical and Health Survey showed that the prevalence of EBP in children and adolescents aged 7-17 years was about 14.5%.Evidence has shown that hypertension can track from childhood to adulthood..Moreover,EBP in children and adolescent not only cause early target organ damage(TOD),including left ventricular hypertrophy(LVH),vascular sclerosis and renal injury,but also increase the risk of atherosclerosis and cardiovascular disease(CVD)in adulthood.Researches suggested that most of early TOD in children and adolescents are functionally changed.If early detection and timely intervention are performed,the TOD in children and adolescents may be reversed.Therefore,it is essential to early identify high-risk children and to develop intervention strategies.Meanwhile,it is also an important way to reduce the burden of CVD in China.Based on the data from the 12th Five Year National Science and Technology Support Program-"Early warning,diagnosis and treatment of cardiovascular disease in children",7840 children and adolescents aged 6-17 years in urban area of Jinan were selected to describe the prevalence of EBP based on the US Fourth Report criteria,Chinese criteria and International criteria,respectively,and 333 children and adolescents with hypertension were recruited to evaluate their target organ damage,which can provide evidence for prevention and control of EBP and TOD in children and adolescents in Jinan.Objectives1.To describe the prevalence of EBP in 7840 children and adolescent aged 6-17 years based on the US Fourth Report criteria,Chinese criteria and International criteria,respectively.2.To describe the TOD in 333 children and adolescents with hypertension based on the Chinese criteria.Subjects and methods1.Data were from the 12th Five Year National Science and Technology Support Program-"Early warning,diagnosis and treatment of cardiovascular disease in children",performed from September 2012 to September 2014.Convenient cluster sampling method was used to select 4 middle-level schools in urban area of Jinan as the sampling points,including 2 primary schools,1 junior high school and 1 senior high school.Children and adolescents,who have possessed Jinan registered residence and have lived in Jinan for at least one year,were selected as research objects.Finally,7840 children and adolescents were recruited,including 4082 boys and 3758 girls.2.Anthropometric measurements,questionnaires,biochemical measurements and TOD measurements were performed in all eligible children and adolescents.Anthropometric measurements included height,weight,blood pressure(BP)and heart rate.Data collected by a questionnaire included the basic information,lifestyle,disease history and parental disease history.Prevalence of pre-elevated blood pressure(Pre-EBP)and EBP were assessed based on the US Fourth Report criteria,Chinese criteria and International criteria,respectively.Blood biochemical test and urine biochemical test were conducted to measure biochemical indicator.Blood biochemical indicators included fasting plasma glucose(FPG),total cholesterol(TC),triglyceride(TG),low density lipoprotein cholesterol(LDL_C),high density lipoprotein cholesterol(HDL_C),alanine aminotransferase(ALT),aspartate transaminase(AST)and blood creatinine(B-CREA).Urine biochemical indicators included uric acid(UA)and urine creatinine(U-CREA).Cardiac test,vascular test,liver test and kidney test were performed to evaluate target organ status.Cardiac indices included left ventricular posterior wall thickness(LVPWT),inter-ventricular septal wall thickness(IVST),left ventricular internal dimension(LVID),left ventricular internal diameter at end-systole(LVDS),left ventricular internal diameter at end-diastole(LVDD),which were used to calculate left ventricular mass index(LVMI),relative wall thickness(RWT)and so on.Vascular indices included carotid intima-media thickness(cIMT).Liver indices included whether there is non-alcoholic fatty liver.Kidney damage was assessed by urine microalbuminuria(U-MAU).Children and adolescents with EBP who participated TOD was evaluated based on Chinese criteria.3.Data were analyzed using SPSS 16.0.Age was expressed as mean±SD,and other continuous variables(height,weight,body mass index(BMI),heart rate,systolic blood pressure(SBP),diastolic blood pressure(DBP),prevalence of biochemical parameters and TOD indices)were expressed as mean±SE.Categorical data(gender,prevalence of overweight,obesity,Pre-EBP,EBP,isolated systolic elevated blood pressure(IS-EBP),isolated diastolic elevated blood pressure(ID-EBP),biochemical indicators and TOD indicators)were presented as percentage(%).The t-test and covariance analysis were used to compare difference in continuous data between groups and Chi-square test was used to compare categorical data between groups.P<0.05 was considered as significant difference.Results1.The prevalence of EBP in children and adolescent aged 6-17 years in urban area of Jinan based on three standardsThe prevalence of Pre-EBP,EBP,IS-EBP and ID-EBP in children and adolescents aged 6-17 years in urban area of Jinan were 11.3%,17.2%,11.2%and 1.9%for the Chinese criteria,14.4%,9.4%,7.2%and 0.7%for the US criteria,13.1%,14.9%,12.0%and 0.8%for the International criteria,respectively.Except for ID-EBP,the prevalence of Pre-EBP,EBP and IS-EBP in boys were higher than that in girls based on three criteria(P<0.001).The prevalence of Pre-EBP,EBP,IS-EBP and ID-EBP based on the Chinese criteria,EBP and IS-EBP based on the US Forth Report criteria,and IS-EBP based on the International criteria were all highest in 12-14 age groups when compared to 6-8,9-11 and 15-17 years age groups(P<0.05).2.The prevalence of TOD and abnormal biochemical indicatorsThe prevalence of elevated LVMI,RWTm,RWTp and eccentric hypertrophy were higher than 25%among the 333 children and adolescents with hypertension who participated in target organ assessment through blood pressure measurements based on three separate occassions.The prevalence of elevated RWTp in four age groups of 6-8,9-11,12-14 and 15-17 years was 41.5%,51.6%,46.3%and 16.2%,respectively(P<0.001).The prevalence of elevated RWPm was 30.2%,43.5%,38.9%and 8.5%(P<0.001),and the prevalence of elevated cIMT was 29.4%,13.2%,8.3%and 9.1%,respectively(P<0.05).The prevalence of non-alcoholic fatty liver was higher in boys than that in girls(14.3%vs.4.2%,P<0.05).There was no significant difference in other groups.Conclusion1.The prevalence of EBP in children and adolescents aged 6-17 years in urban area of Jinan based on three criteria reached a high level,which indicated that pediatric EBP is epidemic.Moreover,the prevalence of EBP was higher in boys than that in girls,and more concentrated in 12-14 age group.2.Among the children and adolescents with hypertension,the prevalence of elevated LVMI,RWTp,RWTm,cIMT,abnornal U-MAU and fatty liver were common.