hypertension ( ht ) is not an adult disease anymore ; it is a silent disease that is generally asymptomatic in childhood and adolescent period .
it plays the important pathophysiological role in the development of the reduction in baroreflex sensitivity and retinal alteration .
hypertension studies in children and adolescents are of great importance since control at this stage is likely to prevent adverse sequelae in later life .
hypertension is a major cause of morbidity , which unless controlled in early life , may tend to introduce a high risk in adulthood . a previous worldwide report records the prevalence of hypertension in children as ranging from 3% to 16.2% .
the diversity of the results in hypertension studies stems from the different criteria used , selection of the age group and study population ( ethnic ) , study area ( urban and rural ) , culture , as well as dietary habits ( socioeconomic ) .
this study was to detect the prevalence and risk factors of hypertension in children / adolescents aged 10 to 17 years .
the objectives and the importance of the study were first explained to the teachers and parents . the children / adolescents aged 1017 years in each selected school in chennai were examined .
two field survey teams , each comprising a medical officer and a social scientist were formed .
the physician elicited medical history and carried out clinical examination including measurement of blood pressure ( bp ) .
the social scientist recorded the background information such as the food frequency questionnaire ( ffq ) and anthropometric measurements .
after getting the child to sit for five minutes , with the back supported and both feet on the floor , systolic and diastolic blood pressures ( sbp ) were measured on the right arm extended over a table at the level of heart with a calibrated standard sphygmomanometer .
a set of different sized cuffs was used to circle the arm completely up to two - thirds of the upper arm without overlapping .
systolic pressure was recorded when the initial sound was heard ( phase i of the korotkoff sound ) ; diastolic pressure was recorded at the disappearance of the sound ( phase v of the korotkoff sound ) .
the arithmetic mean of these three sitting bp measurements was used as the mean sitting office bp ( mssbp ) .
a cross check of 57% of the hypertension subjects at different times by different teams was done for both accuracy and consistency .
every effort was made to avoid staff - child interaction , such as talking , in order to maximize reproducibility .
every effort was made to have the same staff member take the bp measurements of the same child , at the same time of day , using the same equipment .
hypertension was defined as mssbp above the 95 percentile for age , gender , and height as per recommendation of the national high blood pressure education program working group on high bp in children / adolescents ( nhbpep fourth report 2004 ) .
the height and weight were measured with the child standing without shoes ; body mass index ( bmi ) was calculated for all children / adolescents .
information on risk factors for hypertension like family history of hypertension and diabetes mellitus were asked for their socioeconomic status was also assessed .
their reduced physical activities ( arbitrarily children who engaged in a physical activity < 30 min for 4 days per week ) posed a high risk .
hours of watching television and their monthly consumption of oil were also noted as high risk factors .
the fourth report on the diagnosis , evaluation and treatment of high bp in children and adolescents is an authentic source of childhood and adolescent hypertension ( 2004 ) . in this report ,
definition and classification of hypertension in children / adolescents we followed the same ffq - pure study from the south india described earlier for the study monthly per capital income was assessed by the children with a score of 1629 , and above ; modified kuppusamy scale ( 2007 ) was assigned to the upper socioeconomic status and < 15 lower socioeconomic status .
the factors found to be significant by univariate analysis , namely the family history of hypertension , diabetes mellitus , obesity , high socioeconomic status , and female gender were included for multivariate analysis .
the data were collected and entered , after which we manually checked and rechecked for accuracy .
those variables found to be significantly associated were then studied by multivariate analysis logistic regression .
they were screened for hypertension and associated risk factors . there were 2107 girls and 1799 boys [ table 2 ] .
prevalence of hypertension among 10 - 17 year old children and adolescents by age and gender the overall prevalence of hypertension was 9.5% ( 371 ) of 3906 children / adolescents studied ; the prevalence of hypertension in boys was 8% ( 144 of 1799 ) with peak prevalence around 1215 years of age .
children / adolescents with both systolic and diastolic hypertension were 31 ( 21% ) out of 144 . of the girls , the overall prevalence was 10.7% ( 227 ) of 2107 children , with peak prevalence around 1216 years of age .
isolated systolic hypertension was present in 60 girls ( 26.4% ) ; diastolic hypertension alone was seen in 106 children ( 47% ) and 61 ( 26.6% ) out of 227 children had both systolic and diastolic hypertension .
univariate analyses of risk factors for hypertension in these children / adolescents were done [ table 3 ] .
univariate analysis for association between various risk factors and hypertension among 10 - 17 year old children and adolescents the overall prevalence of obesity was 2.7% among the hypertensives ( 106 out of 3906 ) ; 2.1% ( 75 out of 3535 ) in the normotensive obesity in boys was 2% ( 36 out of 1799 ) and 3.32% ( 70 out of 2107 ) in girls .
the overall prevalence of overweight was 5.25% ( 205 out of 3906 ) . in normotensives , the prevalence of overweight was 4.8% ( 170 out of 3535 ) and it was 9.43% ( 35 out of 371 ) in hypertensives .
overweight in boys was 2.17% ( 39 out of 1799 ) and 7.87% ( 166 out of 2107 ) in girls .
a positive family history of hypertension among hypertensives was 13.2% compared to 8.3% of the normotensives .
a positive family history of diabetes mellitus in the hypertensives was 5.3% as against 3.6% of the normotensives .
the prevalence of hypertension in children / adolescents of low socioeconomic families was 8.85% as against 10.2% in children / adolescents of high socioeconomic families .
children / adolescents with hypertension were more likely to be obese than children / adolescents with normal bp ( odds ratio [ or ] : 1.21 [ 2.726.48 ] 95% confidence interval [ ci ] ) . children / adolescents with hypertension were 1.6 times more associated with a family history of hypertension than children with normal bp ( or : 1.66 [ 1.202.30 ] 95% ci ) children who had hypertension were 1.3 times more likely to be girls than the normotensives ( or : 1.39 [ 1.111.72 ] 95% ci ) .
the factors found to be significant by univariate analysis were included in multivariate analysis [ table 4 ] .
family history of hypertension ( or : 1.67 [ 1.212.33 ] 95% ci ) obesity ( or : 4.67 [ 3.007.27 ] 95% ci ) , and overweight ( or : 2.17 [ 1.473.22 ] 95% ci ) were found to be independent risk factors associated with hypertension in the study population .
multivariate logistic regression showed that cases had 1.67 times higher family history , were 4.67 times more obese and were 2.17 times more overweight compared to control children .
multiple logistic regression analysis - factors for hypertension in children and adolescents aged 10 - 17 years
the mean systolic and diastolic bp levels of children were studied in relation to age in both males and females . in both sexes ,
systolic and diastolic bp of boys and girls with age noted agrees with the findings in the task force committee report and other studies .
the varying results may be due to varying age groups in the study , the different criteria adopted to define hypertension , and the basic differences between racial groups as relates to geographic , dietary , and cultural factors . in this study , there were more hypertensive girls ( 10.8% ) than boys ( 8.0% ) , results which do not correlate with those of other studies , in which hypertensive boys were 11.9% ; girls were 11.4% ; prevalence of overweight ( 7.87% ) and obesity ( 3.32% ) in girls was higher than overweight ( 2.17% ) and obesity ( 2% ) in boys . in our study ,
the prevalence of obesity was 2.7% , which is higher than that reported by another another study .
positive family history of diabetes mellitus among hypertensives was 5.3% as against 3.6% in normotensives , which is similar to the study by chanda et al .
hypertension in obese children / adolescents was 8.35% , which was twice what was observed by other study groups . in this study
, there was a positive family history of hypertension in 8.3% , which is less than what was observed by another indian study .
significant risk factors for hypertension in adolescents in our study by univariate analysis were obesity , overweight , and a positive family history of hypertension , which agreed with a previous study .
there is an increasing trend toward a high prevalence of hypertension in children of school age as a result of obesity and positive family history of hypertension and diabetes mellitus .
high socioeconomic status , faulty lifestyle , dietary habits , and physical inactivity are key factors which must be dealt with immediately and aggressively . based on our findings , hypertension is no more a disease that comes at a later stage in life .
it is crucial to advise obese children to modify their lifestyle with respect to diet , exercise , and salt intake to maintain a normal bp and avoid the childhood onset of adult hypertension .
 background : since the data of primary hypertension ( ht ) in children is scanty in india , this study attempted to evaluate ht by a multidimensional investigation of the various risk factors in children and adolescents.materials and methods : a total of 3906 subjects were recruited , all of whom lived in chennai , an urban area of tamil nadu . 
 the children and adolescents aged from 10 to 17 years were selected by random sampling . 
 the children / adolescents were randomized into one control and further divided into two groups . 
 the national high blood pressure education program fourth report ( 2004 ) and anthropometric body mass index ( bmi ) , food frequency questionnaire ( pure ) were followed in the study.results:out of 3906 children , 2107 were girls and 1799 boys . 
 on screening , we found 9.5% to be hypertensive with the prevalence rate of boys and girls 8% and 10.8% , respectively . 
 overall obesity was 2.7% , ( boys 2% , girls 3.32% ) ; hypertensives and normotensives were 8.4% and 2.1% , respectively . 
 we found that overweight ( odds ratio [ or ] : 2.06 [ 1.403.01 ] 95% confidence interval [ ci ] ) , obese children ( or : 1.21 [ 2.726.48 ] 95% ci ) , and those with a family history of ht ( or : 1.66 [ 1.202.30 ] 95% ci ) had increased risk of hypertension . 
 females were 1.39 times ( or : 1.39 [ 1.111.72 ] 95% ci ) more at risk of getting ht . 
 multivariate analysis showed that obese children / adolescent were four times more likely to have ht than children with normal bmi ( or : 4.67 [ 3.007.26 ] 95% ci].conclusion : family history of ht , obesity , and female gender are associated with a high risk of ht . 
 the prevalence of ht was higher among obese adolescents than among slender subjects . 
 this may be related to their sedentary lifestyle , faulty eating habits , high fat content in the diet and little physical activity . 
INTRODUCTION
MATERIALS AND METHODS
RESULTS
DISCUSSION
CONCLUSION
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