the risk for populational diseases differs markedly between geographic regions and countries , as , for example , the reported greater rate of cardiovascular mortality in estonia compared to austria .
the latest age standardised ischemic heart disease ( ihd ) mortality data per 100 000 population are for austria 80,68 , while for estonia 254,25 .
so far , the studies investigating cardiovascular disease ( cvd ) risk factors focused on adult obesity and associated metabolic disorders .
however , for the assessment of populational health , it is of outmost interest to gain a better insight in the pediatric roots of cvd .
although it is well established that obesity and the subcutaneous adipose tissue ( sat ) phenotype are essentially involved in cvd risk , little information exists about risk phenotypes in prepubertal obese children .
notably , the prevalence of childhood obesity increased 4-fold during the last 20 years , and this represents a strong risk factor for obesity of adulthood .
an improved understanding of individual subcutaneous body fat distribution and body composition in children may essentially support the development of effective preventive strategies [ 47 ] for the metabolic syndrome and cvd [ 711 ] .
various methods to evaluate body composition in children exist . due to the necessary technical equipment ,
some of these methods are very expensive besides being inappropriate for the use in field studies .
0516251 ) was developed to generate noninvasive , quick , accurate , and safe measurements of a monolayer of subcutaneous adipose tissue ( sat ) at any given site of the human body .
technical features and validation results were based on computed tomography as reference system [ 12 , 13 ] .
the lipometer allows the measurement of subcutaneous fat distribution and the determination of the subcutaneous adipose tissue topography ( sat - top ) .
previous results using the lipometer to determine the sat - top emphasize the importance of describing subcutaneous adipose tissue in adult obesity and metabolic syndrome as well as during childhood and adolescence [ 1417 ] .   marked differences of mortality rates were seen between eu member states as analysed by the topology of male mortality .
austria belongs to  type 1  with an almost average mortality , and estonia is presented in 
thus , we hypothesize herein the presence of high risk cardiovascular sat - top phenotype already present in estonian children .  
this study analysed the subcutaneous body fat distribution in a sample of 553 clinically healthy male prepubertal boys aged around 11 years living in austria or estonia .
the participants and their parents consented to the study after receiving a thorough explanation of the declaration of consent .
the procedure chosen was in accordance with the declaration of helsinki and the local ethics committee recommendations .
height , weight , and sat - top were measured in 553 boys aged 11,1 ( 0,8 ) years . since there is a peak of fat mass in boys at the age of 11 years , we recruited individuals aged 10,0 to 12,0 years .
the participants were recruited in different schools and outpatient clinics from urban areas as well as in the local university clinic for pediatrics and adolescent medicine in graz , austria , and tartu , estonia . in graz , boys of similar age were recruited from the styrian juvenile obesity study , which were designed to investigate early atherosclerosis and metabolic disorders in obese juveniles . in estland , boys were recruited from a running preventive study on obesity and exercise . none of the studied children suffered from endocrine or syndromal disorders or were on any medication .
body mass was measured to the nearest 0.01  kg using calibrated electronic scales ( soehnle 7700 , murrhardt , germany ) .  
weight was measured in underwear to the nearest 0.1  kg using a calibrated balance scale .
we used box - cox transformation to calculate bmi as a measure for degree of overweight due to the skewness of the bmi distribution .
in addition to the reported group of austrian and estonian boys , we included the age development of 960 healthy controls aged from 9 ( m09 ) to 80 years ( m80 ) who were recruited from health and fitness checks in austria and austrian male adult patients with type 2 diabetes ( t2 dm ) , coronary heart disease ( chd ) , and persons with extremely thin fatty tissue layers ( anorexia and body builders ) ( published in [ 15 , 23 ] for visual comparison in a two - dimensional factor plot ) .
measurements of sat thickness were performed by means of a patented optical device ( eu pat .
0516251 ) on 15 anatomically well - defined body sites distributed from neck to calf on the right and left side of all children and then averaged for both body sides .
the sensor head of the lipometer , that is held perpendicular to the measurement site , consists of a light source of light - emitting diodes (  = 660  nm , light intensity 3.000 mcd ) and a photodetector that measures the corresponding light intensities that are back scattered in the sat .
calibration and evaluation were done using computer tomography ( ct ) as the reference method .   to obtain the lipometer measurement values and the corresponding absolute values of ct for subcutaneous adipose tissue thickness ,
ct scans at defined levels ( upper abdomen , lower abdomen , and extremities ) were made by a third generation ct scanner ( somatom dr3 , somatom dhr , siemens , erlangen , germany ) .
these levels were marked , and lipometer measurements were performed step by step around the body circumferences .
thus , a set of datapoints of both , lipometer light patterns and corresponding absolute values of subcutaneous adipose tissue thickness from ct , ranging from 0.9 to 47.3  mm , was obtained .
final results were obtained by nonlinear regression ( r = 0.9863 ) , investigating different curve types such as polynomials from 2nd to 5th order , potential equations , and exponential equations .
a detailed sat profile of a subject is obtained by measuring the complete set of 15 specified body sites [ 12 , 13 ] .
means were compared by a two - tailed unpaired sample t - test or by mann - whitney u - test , depending on the distribution of the data . a value of p < 0.05 was considered statistically significant .  
stepwise discriminant analysis is concerned with selecting the most important variables whilst retaining the highest discrimination power possible .
stepwise linear discriminant analysis was applied to study whether single sat layers or the combination of sat layers or tbf mass could enable correct classification between estonian versus austrian boys .   for visual comparison ,
the 15-dimensional sat - top information was condensed by factor analysis into a two - dimensional factor plot .
the factor analysis shown in figure 1 condenses the 15-dimensional sat - top information in a two - dimensional factor plot .
factor 1 , the x - axis , represents the trunk body fat development , whereas factor 2 , the y - axis , represents the corresponding data of the extremities .

 table 1 shows basic anthropometric data of the experimental groups and the details of the lipometer analysis encompassing estonian ( e ) and austrian ( a ) boys .   a discriminant analysis using all 15 sat - top values , bmi , and the total body fat ( tbf ) in kg yields the following classification results : 84,6% of 553 boys are correctly classified in estonians and austrians selecting the body sites 1-neck , 2-triceps , 3-biceps , 5-front chest , 6-lateral chest , 7-upper abdomen , 10-hip , 12-lateral thigh , and 13-rear thigh for the discriminant function .  
the factor analysis shown in figure 1 condenses the 15-dimensional sat - top information in a two - dimensional factor plot .
factor 1 , the x - axis , represents the trunk body fat development , whereas factor 2 , the y - axis , represents the corresponding data of the extremities .
the lower line in the figure shows the age development of healthy male controls aged from 9 ( m09 ) to 80 years ( m80 ) .
nine - year - old boys have thin fat layers at the trunk . near the age of 17 years
, the young males typically have decreasing thicknesses of adipose tissue layers at the extremities . between 17 and 40 years , the young males increase their fat layers on the trunk ( m17 , m22 , m30 , and m40 ) . for comparison ,
the upper line shows the age - dependent sat - top development of females from 9 ( f09 ) to 80 years ( f80 ) , respectively .
austrians have thicker sat layers at the extremities ( higher values of factor 2 see figure 1 ) , whereas estonians show markedly stronger fat layers at their trunks .
notably , compared to austrians , the position of obese estonian boys is critically nearer to male adult patients with type 2 diabetes ( t2 dm ) and coronary heart disease ( chd ) in the factor plot ( figure 1 ) .
in this study , for the first time , a detailed sat - top analysis of austrian and estonian prepubertal boys is presented .
this observation might initiate more detailed future research to characterize deviations of sat - top underlying populational - based diseases .  
this prevalence remained high over the last 20 years . in 1990 , it was estimated to be approximately three times higher than that of corresponding swedish males in the same age group .
the importance of body fat measurements in children for the implementation of strategies to fight against the development of metabolic diseases is evident .
sex differences in the developing health risks from obesity are important to be included in terms of optimal risk management strategies .
the incidence of obesity in boys is an upcoming growing problem in our society [ 25 , 26 ] .  
the main pathologic sequels of metabolic diseases are undoubtedly driven by excess fat mass . however , the fat distribution is most probably more important than the total body fat mass [ 2729 ] .
fat reference curves for children   show that boys have a relatively flat 50th centile varying between 15% and 18% body fat over the entire age range from 5 to 18 years with a peak at the age of 11 years .
variability increases up to the age of 11 years with a marked increase in positive skewness .
addo and himes published new reference curves for triceps and subscapular skinfold thicknesses in us children and adolescents . especially in research settings , the sat - top determined by lipometry is an important valid anthropometric indicator of regional and total body fatness .
the individual  landscape  of subcutaneous fat identified by the lipometer is very specific for the adipose tissue phenotype caused by the interplay between genetic and environmental factors .
an essential advantage of the lipometer to other methods is the quick and noninvasive approach without radiation burden .  
the few studies which have examined so far ethnic differences in adiposity in children and adolescents used advanced body composition measurement techniques with potential side effects ( radiation burden ) such as dual - energy x - ray absorptiometry and densitometry .   taken together , our results , achieved by a complex anthropometric analysis , identified for the first time in young male estonians a sat phenotype which is very similar to that of male adult patients with manifest type 2 diabetes ( t2 dm ) and coronary heart disease ( chd ) .
these observations may suggest a presence of a genetic risk predisposition for cardiovascular / metabolic abnormalities , which underlines the exceptional importance of early life style interventions for this population .
 
 objective . 
 risk phenotypes for cardiovascular disease ( cvd ) differ markedly between countries , like the reported high difference in 
 cvd mortality in austria and estonia . 
 hitherto , the goal of this study was to find out risk profiles in body fat distribution yet present in childhood , paving the way for later clinical end points . 
 methods . 
 he subcutaneous adipose tissue ( sat ) distribution patterns in 553 austrian ( a ) and estonian ( e ) clinically healthy normal weight boys aged 11.1 ( 0.8 ) years were analysed . 
 we applied the patented optical device lipometer which determines the individual subcutaneous adipose tissue topography ( sat - top ) . 
 results . 
 total body fat did not differ significantly between e and a boys . a discriminant analysis using all lipometer data , bmi , and the total body fat ( tbf ) yielded 84.6% of the boys correctly classified in estonians and austrians by 9 body sites . 
 a factor analysis identified the sat distribution of e as critically similar to male adult patients with coronary heart disease ( chd ) . 
 conclusions . 
 we show in normal weight estonian boys a highly significant decreased fat accumulation on the lower body site compared to age matched austrian males . 
 this sat - top phenotype may play an important role for the increased cardiovascular risk seen in the estonian population . 
1. Introduction
2. Subjects and Methods
3. Results
4. Discussion