the young hearts project 2000 is a cross - sectional cohort study which took place in 19992001 following a previous study , young hearts i , described in detail elsewhere .
the young hearts project 2000 had a total of 2,017 participants from northern ireland , consisting of 12- and 15-year - olds from 36 nationally representative schools ; the response rate was 65.4% .
eligible subjects were selected using a computer - generated random number list , divided into groups according to age and gender , resulting in approximately 500 participants in each of the four age / sex groups .
age was defined as years of age  6 months ( e.g. , a 12-year - old child ranges from 11.5 to 12.5 years ) .
inflammation markers were only measured in a subsample of the total population . in this subsample , a distinction was made between normal , overweight , and obese subjects ( according to the classification by cole et  al . ) .
the prevalence of overweight and obesity in the complete cohort was 16.2% and 14.7% , respectively . in the present study sample , all obese adolescents ( n = 95 )
were selected and matched according to age , gender , and smoking status , with overweight and normal weight children .
because of problems in obtaining a blood sample from three of the obese adolescents , the final number of participants in each of the three groups was reduced to 92 .
written informed consent was signed by the participants and the participants ' parent or guardian . for each child , the examination included a medical examination , cardiorespiratory fitness test , dietary examination , and a parental and physical activity questionnaire .
the medical examination included weight ( nearest 100 g , seca 770 electronic weighing scale ) and height ( nearest mm , holtain stadiometer ) using standard techniques , with participants in light clothing and without shoes .
body mass index was calculated as weight ( kg)/height ( m ) . peripheral venous blood ( 16 ml )
was obtained by venepuncture in fasting state and collected into serum - z - clot activator edta - sodium or lithium heparin - coated tubes .
samples were transported in a chilled insulated container , and serum / plasma was removed after centrifugation at 100  g for 10 minutes at 4c within 4 hours from venepuncture and stored at 70c . because cvd risk is seldom clinically defined at this age , a clustered score for biological risk factor can be used to specify subjects at risk [ 79].clustered cvd risk in the present study  was computed using scores for mean arterial pressure ( map ) , ldl : hdl cholesterol ratio , cardiorespiratory fitness , skinfolds , and triglyceride levels .
blood pressure was measured twice from the right arm using a hawksley random zero sphygmomanometer , with subjects sitting down quietly beforehand for at least 5 minutes .
systolic blood pressure ( sb ) was recorded as the mean of the two values for korotkoff phase 1 , whereas the diastolic blood pressure ( db ) was based on the mean of the two values for korotkoff phase v ( 15-year - old ) or phase iv ( 12-year - old ) .
total plasma - cholesterol , hdl - cholesterol , and plasma triglyceride were determined ( boeringer , mannheim , germany ; cobas fara automated analyzer ) according to the world health organization ( who ) standards of quality control .
four skinfold thickness measurements ( triceps , biceps , subscapula , and suprailiac ; mm ) were taken in duplicate on the left side of the body according to durnin and rahaman .
subjects ran a distance of 20 m at a fixed speed , and the pace was increased by .5 km / hr every minute .
physical activity was estimated by a self - administered recall questionnaire under the supervision of an exercise physiologist . the questionnaire assessed frequency , intensity , and duration of habitual activity and allocated scores out of 100 [ 18,2325 ] .
each nutritionist consulted with a similar number of participants from each group , and inter - observer reproducibility was confirmed before sampling . the mean daily caloric intake ( kcals )
was calculated from the 7-day recall diet history interview using the nutrition analysis software programme wisp ( tinuviel software , warrington , uk ) , and recorded for each subject .
smoking status was determined using a self - administered questionnaire on smoking and daily number of cigarettes smoked .
plasma levels of sicam and svcam were determined using commercially available monoclonal elisa kits ( diaclone , immunodiagnostic systemd , ltd ) according to the recommendations of the manufacturer .
mean inter - assay coefficients of variation for sicam and svcam elisas were 4.7% and 4.2% , respectively .
plasma hscrp was quantified by a high sensitivity latex - enhanced immunoturbidimetric assay ( wako chemicals gmbh ) using a cobas fara automated analyzer ( roche diagnostics , uk ) .
clustered cvd risk scores were computed using a sum of age- and gender - specific z - scores .
triglyceride , cholesterol ratio , and cardiorespiratory fitness measures were log transformed to meet the assumption of normal distribution .
the existence of clustering between the biological risk factors was determined with pair - wise pearson correlation coefficients . to determine whether inflammation markers relate to clustered cvd risk independent of established lifestyle risk factors ,
first , univariate analyses were performed to analyze the relationship between single determinants and clustered cvd risk .
second , a multiple regression analysis with a forward selection procedure was performed in which both lifestyle risk factors and inflammation markers were included as possible determinants . a threshold significance value of 10% ( p
= .10 ) was assigned for the inclusion of variables in the final prediction model .
r were used to give an indication of the quality of the final prediction model .
all statistical analyses were performed in statistical package for the social sciences ( spss inc , chicago , il ) , version 16.0 .
the young hearts project 2000 is a cross - sectional cohort study which took place in 19992001 following a previous study , young hearts i , described in detail elsewhere .
the young hearts project 2000 had a total of 2,017 participants from northern ireland , consisting of 12- and 15-year - olds from 36 nationally representative schools ; the response rate was 65.4% .
eligible subjects were selected using a computer - generated random number list , divided into groups according to age and gender , resulting in approximately 500 participants in each of the four age / sex groups .
age was defined as years of age  6 months ( e.g. , a 12-year - old child ranges from 11.5 to 12.5 years ) .
inflammation markers were only measured in a subsample of the total population . in this subsample , a distinction was made between normal , overweight , and obese subjects ( according to the classification by cole et  al . ) .
the prevalence of overweight and obesity in the complete cohort was 16.2% and 14.7% , respectively . in the present study sample , all obese adolescents ( n = 95 )
were selected and matched according to age , gender , and smoking status , with overweight and normal weight children .
because of problems in obtaining a blood sample from three of the obese adolescents , the final number of participants in each of the three groups was reduced to 92 .
written informed consent was signed by the participants and the participants ' parent or guardian .
for each child , the examination included a medical examination , cardiorespiratory fitness test , dietary examination , and a parental and physical activity questionnaire .
the medical examination included weight ( nearest 100 g , seca 770 electronic weighing scale ) and height ( nearest mm , holtain stadiometer ) using standard techniques , with participants in light clothing and without shoes .
body mass index was calculated as weight ( kg)/height ( m ) . peripheral venous blood ( 16 ml )
was obtained by venepuncture in fasting state and collected into serum - z - clot activator edta - sodium or lithium heparin - coated tubes .
samples were transported in a chilled insulated container , and serum / plasma was removed after centrifugation at 100  g for 10 minutes at 4c within 4 hours from venepuncture and stored at 70c .
because cvd risk is seldom clinically defined at this age , a clustered score for biological risk factor can be used to specify subjects at risk [ 79].clustered cvd risk in the present study  was computed using scores for mean arterial pressure ( map ) , ldl : hdl cholesterol ratio , cardiorespiratory fitness , skinfolds , and triglyceride levels .
blood pressure was measured twice from the right arm using a hawksley random zero sphygmomanometer , with subjects sitting down quietly beforehand for at least 5 minutes .
systolic blood pressure ( sb ) was recorded as the mean of the two values for korotkoff phase 1 , whereas the diastolic blood pressure ( db ) was based on the mean of the two values for korotkoff phase v ( 15-year - old ) or phase iv ( 12-year - old ) .
total plasma - cholesterol , hdl - cholesterol , and plasma triglyceride were determined ( boeringer , mannheim , germany ; cobas fara automated analyzer ) according to the world health organization ( who ) standards of quality control .
four skinfold thickness measurements ( triceps , biceps , subscapula , and suprailiac ; mm ) were taken in duplicate on the left side of the body according to durnin and rahaman .
subjects ran a distance of 20 m at a fixed speed , and the pace was increased by .5 km / hr every minute .
physical activity was estimated by a self - administered recall questionnaire under the supervision of an exercise physiologist . the questionnaire assessed frequency , intensity , and duration of habitual activity and allocated scores out of 100 [ 18,2325 ] .
each nutritionist consulted with a similar number of participants from each group , and inter - observer reproducibility was confirmed before sampling .
the mean daily caloric intake ( kcals ) was calculated from the 7-day recall diet history interview using the nutrition analysis software programme wisp ( tinuviel software , warrington , uk ) , and recorded for each subject .
smoking status was determined using a self - administered questionnaire on smoking and daily number of cigarettes smoked .
plasma levels of sicam and svcam were determined using commercially available monoclonal elisa kits ( diaclone , immunodiagnostic systemd , ltd ) according to the recommendations of the manufacturer .
mean inter - assay coefficients of variation for sicam and svcam elisas were 4.7% and 4.2% , respectively .
plasma hscrp was quantified by a high sensitivity latex - enhanced immunoturbidimetric assay ( wako chemicals gmbh ) using a cobas fara automated analyzer ( roche diagnostics , uk ) .
clustered cvd risk scores were computed using a sum of age- and gender - specific z - scores .
triglyceride , cholesterol ratio , and cardiorespiratory fitness measures were log transformed to meet the assumption of normal distribution .
the existence of clustering between the biological risk factors was determined with pair - wise pearson correlation coefficients . to determine whether inflammation markers relate to clustered cvd risk independent of established lifestyle risk factors ,
first , univariate analyses were performed to analyze the relationship between single determinants and clustered cvd risk .
second , a multiple regression analysis with a forward selection procedure was performed in which both lifestyle risk factors and inflammation markers were included as possible determinants . a threshold significance value of 10% ( p
= .10 ) was assigned for the inclusion of variables in the final prediction model .
r were used to give an indication of the quality of the final prediction model .
all statistical analyses were performed in statistical package for the social sciences ( spss inc , chicago , il ) , version 16.0 .
table 2 shows the pair - wise pearson correlation matrix for the biological risk factors . on the basis of the partial correlations ,
clustering of biological risk factors seems to exist , that is , all pearson correlations between the biological risk factors were positive and significant .
table 3 shows the pair - wise pearson correlation matrix for inflammation markers with univariate and clustered cvd risk variables .
the best prediction model included hscrp , sicam , and svcam and showed an explained variance of 26 % .
to our knowledge , this is the first study to associate markers of inflammation and endothelial dysfunction with clustered cvd risk in adolescents .
the main finding of this study was that these markers were strong predictors for cvd risk in adolescents , unlike lifestyle factors which were not predictive .
the markers sicam and hscrp were positively related to cvd risk , whereas an inverse relation for svcam was found .
first , membrane - bound icam and vcam are involved in leukocyte adhesion and migration to the vessel wall as seen in atherosclerosis .
these markers , however , can not be easily measured without invasive techniques . therefore , soluble adhesion molecules ( scam ) are used as a surrogate for membrane bound levels , based on the assumption that soluble levels are indicative of the processes at the endothelium . although the soluble markers have previously been found to be elevated in children at risk ,
although svcam is mainly a product of endothelial cells , sicam is produced by many other cell types throughout the body .
some studies have  found that the contribution of sicam and svcam in  atherosclerosis is similar , whereas others have found high  expression of sicam in healthy subjects associated with cvd risk and high levels of svcam in ongoing stages of atherosclerosis and cvd outcomes [ 3,17,2830 ] .
such associations of vcam need not exist in a healthy adolescent population as currently used .
the inverse relation of svcam as found in the current study could , therefore , indicate lower incidence of ongoing stages of vascular damage in this population . limitations of the study design merit consideration .
although the study provides a representative population , the cross - sectional design of the study can not provide information on change over time .
nevertheless , a clustered risk score is an accepted method of prediction of cvd risk .
all variables used in the clustered risk were taken into account using the same weighting .
published data do not indicate that one variable should be weighted more heavily than another . although lifestyle variables did not contribute to cvd risk prediction in this study , we should be careful with the interpretation of this result because lifestyle variables were measured by self - report .
finally , the rather large percentage of obese and overweight subjects compared with a normal population did not influence the results , that is , the final regression model remained more or less the same even when analyses were performed separately for the body mass index groups ( data not shown ) .
results not only confirm a role for inflammation and endothelial dysfunction but also prompt further research on the mechanistic level . at this point , conclusions to redirect the prevention of cvd are preliminary and thus efforts should remain concentrated on classical risk prediction and preventive strategies .
 purposethe traditional approach for identifying subjects at risk from cardiovascular diseases ( cvd ) is to determine the extent of clustering of biological risk factors adjusted for lifestyle . 
 recently , markers of endothelial dysfunction and low grade inflammation , including high sensitivity c - reactive protein ( hscrp ) , soluble intercellular adhesion molecules ( sicam ) , and soluble vascular adhesion molecules ( svcam ) , have been included in the detection for high risk individuals . 
 however , the relationship of these novel biomarkers with cvd risk in adolescents remains unclear . 
 the purpose of this study , therefore , was to establish the association of hscrp , sicam , and svcam with cvd risk in an adolescent population.methodsdata from the young hearts 2000 cross - sectional cohort study , carried out in 19992001 , were used . from a total of 2,017 male and female participants , 
 95 obese subjects were identified and matched according to age , sex , and cigarette smoking , with 95 overweight and 95 normal - weight adolescents . 
 clustered cvd risk was computed using a sum of z - scores of biological risk factors . 
 the relationship was described using multiple linear regression analyses.resultshscrp , sicam , and svcam showed significant associations with cvd risk . 
 hscrp and sicam had a positive relation with cvd risk , whereas svcam showed an inverse relationship . in this study 
 , lifestyle factors showed no relation with cvd risk.conclusionthe results fit the hypothesized role of low grade inflammation and endothelial dysfunction in cvd risk in asymptomatic adolescents . 
 the inverse relationship of vcam , however , is hard to explain and indicates the complex mechanisms underlying cvd . 
 further research is needed to draw firm conclusions on the biomarkers used . 