921 Normal-Weight, Overweight Or Obese Children and Adolescents Living in Central Europe

PEDIATRIC ORIGINAL ARTICLE Ethnicity and cardiovascular risk factors: evaluation of 40 921 normal-weight, overweight or obese children and adolescents living in Central Europe

L Martin1, J Oepen2, T Reinehr3, M Wabitsch4, G Claussnitzer5, E Waldeck6, S Ingrisch7, R Stachow8, M Oelert9, S Wiegand1,11 and R Holl10,11 on behalf of the APV Study Group and the German Competence Network Adipositas12

BACKGROUND AND AIMS: Cardiovascular disease (CVD) is a major global health problem and the leading cause of death in Europe. Risk factors such as obesity and hypertension that accelerate the development of CVD begin in childhood. Ethnicity is a known risk factor for CVD in adults. The aim of this study is to explore differences in the prevalence of hypertension and dyslipidemia among overweight/obese and normal-weight children/adolescents of three different ethnic origins living in Central Europe. METHODS AND PROCEDURES: Prevalence of hypertension and dyslipidemia was calculated among obese/overweight children/ adolescents (n = 25 986; mean age 12.7 ± 3.0 years; range: 0–18 years; 46% males) documented in the German-Austrian-Swiss APV (Prospective Documentation of Overweight Children and Adolescents) registry and among normal-weight subjects (n = 14 935; mean age: 8.8 ± 5.1years; range 0–18 years; 51% males) from the population-based cross-sectional German Health Interview and Examination Survey for Children and Adolescents (KiGGS) study. In both cohorts, subjects were categorized into three ethnic groups (Central European: Germany, Austria, Switzerland; Southeastern European: Turkish; Southern European: Spain, Portugal, Italy, Greece, Cyprus, Malta) based on the country of birth of both parents. Regression models were used to examine ethnic differences after adjustment for age and gender and body mass index (BMI) category. RESULTS: Age-, gender- and BMI category-adjusted prevalence of hypertension were 38% and 39% for the ethnic minority groups, compared with 35% among German/Austrian/Swiss counterparts. Turkish ethnicity was significantly associated with hypertension (odds ratio (OR) 1.14; 95% confidence interval: 1.02–1.27; P = 0.0446). No significant ethnic differences were found in lipid levels. Prevalence of hypertension found among normal-weight subjects (Central European vs Southeastern vs Southern European: 6.8% vs 6.3% vs 7.2%) did not differ significantly. CONCLUSIONS: Turkish obese/overweight children/adolescents showed a significantly higher prevalence of hypertension relative to their peers of Central European descent. No significant ethnic difference in the prevalence of hypertension was found among normal-weight children/adolescents. The high prevalence of hypertension among Turkish obese/overweight children/adolescents indicates the need for greater preventive and therapeutic efforts to reduce cardiovascular risk factors among vulnerable populations. International Journal of Obesity (2015) 39, 45–51; doi:10.1038/ijo.2014.167

INTRODUCTION adulthood,4,5 CVDs increasingly have their roots already in early In Europe, and globally, the most common cause of mortality is childhood. non-communicable diseases. Among non-communicable diseases, CVDs and its risk factors affect every ethnic group, but 6 cardiovascular diseases (CVDs) constitute the largest share.1 High inequalities exist among ethnic minority groups. A systematic blood pressure (BP), as a modiﬁable cardiovascular risk factor, has review on CVD risk among adult Turkish and Moroccan migrant been identiﬁed as the leading risk factor for global disease groups living in Europe has shown that obesity and diabetes are burden.2 Giving the increasing prevalence of pediatric obesity,3 more prevalent among migrant groups than among native Central which is frequently accompanied by several other cardiovascular European individuals.7 With regard to obesity prevalence, a similar risk factors, such as hypertension and dyslipidemia, and the pattern was found for youths living in Germany. The population- knowledge that those risk factors can be tracked into based representative survey German Health Interview and

1Department of Pediatric Endocrinology and Diabetology, Charité Children's Hospital, Charité University Medicine, Berlin, Germany; 2Viktoriastift Bad Kreuznach, Rehabilitation Clinic for Children and Adolescents, Bad Kreuznach, Germany; 3Vestische Children's Hospital, University of Witten/Herdecke, Datteln, Germany; 4Divison of Pediatric Endocrinology, Diabetes and Obesity Unit, University Children's Hospital, University of Ulm, Ulm, Germany; 5Spessart-Klinik, Rehabilitation Clinic for Children and Adolescents, Bad Orb, Germany; 6Edelsteinklinik, Rehabilitation Clinic for Children and Adolescents, Bruchweiler, Germany; 7Fachklinik Gaißach, Rehabilitation Clinic, Gaißach, Germany; 8Fachklinik Sylt, Rehabilitation Clinic for Children and Adolescents, Westerland, Germany; 9Katholisches Kinderkrankenhaus Wilhelmstift, Wilhelmstift Catholic Children's Hospital, Hamburg, Germany and 10Institute of Epidemiology and Medical Biometry, University of Ulm, Ulm, Germany. Correspondence: Dr S Wiegand, Department of Pediatric Endocrinology and Diabetology, Charité Children's Hospital, Charité University Medicine Berlin, Augustenburger Platz 1, Berlin 13353, Germany. E-mail: [email protected] 11These authors contributed equally to this work. 12List of participating centers are listed before references. Received 24 March 2014; revised 9 August 2014; accepted 2 September 2014; accepted article preview online 12 September 2014; advance online publication, 7 October 2014 Cardiovascular risk in multiethnic pediatric cohorts L Martin et al 46 Examination Survey for Children and Adolescents (KiGGS) as well anthropometric parameters were documented routinely in specialized as preschool data collected by the German federal states have obesity centers according to the standardized specifications of the German indicated that 11- to 13-year-old children from migrant families Working Group of Childhood Obesity (AGA),19 as described previously.15 For the KiGGS study, a detailed description of data collection has been had an obesity prevalence of 10.0% compared with 6.4% among 20 their German peers.8,9 Similar results were found by Fredriks described previously. In both cohorts, BP was measured under et al.10 in a cohort of children of different ethnic backgrounds standardized conditions according to the guidelines of the German Hypertension League (Deutsche Hochdruckliga).21,22 Serum lipids were living in the Netherlands. Apart from childhood obesity, in Europe analyzed according to the guidelines of the Federal Chamber of there, in particular, is a shortage of information on the prevalence Physicians23 in accredited local laboratories (APV study) and centrally in of cardiovascular risk factors among children/adolescents of the laboratory of the German Herzzentrum Berlin (KiGGS study).24 In the ethnic minority groups. The existing studies have only been KiGGS study, non- fasting blood samples were collected.24 carried out among relatively small numbers of pediatric patients. They show that unfavorable cardiovascular profiles are more often 11–14 Operationalization of study variables in both samples (KiGGS and found in obese children/adolescents of certain ethnic groups. APV) We therefore defined the following hypothesis: (1) Overweight/ Weight status for age and gender was assessed by BMI (body weight (kg)/ obese children/adolescents with a Turkish migration background 2 body height (m) ). BMI was standardized by conversion to an SDSLMS score show a higher prevalence of hypertension and dyslipidemia than using the German national reference data that are also valid for Austrian their counterparts of German/Austrian/Swiss origin. (2) No ethnic and Swiss children.25 According to German guidelines, normal weight in differences in the prevalence of hypertension and dyslipidemia children was defined as a BMI o90th percentile, overweight as a BMI are seen in normal-weight children/adolescents. 490th and ⩽ 97th percentile, obesity as a BMI 497th and ⩽ 99.5th percentile and extreme obesity as a BMI 499.5th percentile.19 BP was classified for age, sex and height based on the Fourth Report on PATIENTS AND METHODS the Diagnosis, Evaluation and Treatment of High BP in Children and 26 Subjects Adolescents, according to the guidelines of the European Society of Hypertension.27 Hypertension was diagnosed if either systolic and/or Data from two major surveys were analyzed: first, the ongoing multicenter diastolic BP was elevated above the 95th percentile for age and gender, APV (Prospective Documentation of Overweight Children and Adolescents) according to the US population-based reference values (Fourth Report).26 initiative records routine data on overweight/obese children/adolescents We used the Fourth Report to present internationally comparative data. presenting at specialized treatment institutions in Germany, Switzerland Abnormal lipid levels (dyslipidemia) were defined according to the and Austria. For the collection of anonymized data at the participating APV guidelines of the American Heart Association for primary prevention of centers, a computer software is applied for standardized longitudinal atherosclerotic CVD beginning in childhood:28 total cholesterol above documentation of demographics, weight category and medical comorbid- − 1 − 1 15 5.18 mmol l (4 200 mg dl ), low-density lipoprotein (LDL)-cholesterol ity, as well as treatment intensity and duration, as described previously. − − above 3.4 mmol l 1 (4130 mg dl 1), high-density lipoprotein (HDL)- As of December 2013, the APV database contained data on 80 812 − 1 o − 1 patients, collected at 198 participating outpatient and in-patient treatment cholesterol below 0.9 mmol l ( 35 mg dl ) and triglycerides above 1.71 mmol l − 1 (4150 mg dl − 1). Triglyceride measurements in the APV centers in Germany, Austria and Switzerland. Each participating center fi ‘ ’ complies with its local ethical and data management guidelines. population were used when the sample was de ned as fasting .As preanalytical procedures were not standardized (variable fasting time) in Information on migration background, BP and lipid levels were available 29 for 25 986 overweight/obese pediatric patients aged 0–18 years from 126 the KiGGS study, triglyceride measurements in KiGGS subjects have to be treatment centers. interpreted with caution. To describe cardiovascular risk factors by ethnic group among normal- The ethnic group was obtained by self-report. We allocated children into weight children/adolescents, we performed a secondary data analysis of German/Austrian/Swiss, Turkish or Southern European groups if both the KiGGS database.16 Detailed description of the KiGGS methodology has 17 been published elsewhere. In brief, the KiGGS survey was a cross- Table 1. Characteristics of the overweight/obese patients (APV) and sectional and longitudinal study conducted from May 2003 to May 2006 the normal-weight subjects (KiGGS) aiming at a nationally representative sample of children and adolescents 0–17 years of age with main residence in Germany. A total of 17 641 Parameter Overweight/obese Normal-weight children and adolescents participated in this survey. Altogether, 2590 patients subjects children/adolescent with a migration background (both parents born (APV registry) (KiGGS survey) outside Germany) took part in the survey. They accounted for 17.1% of all children/adolescents. The two largest groups among the migrant children 18 Sample size (n) 25 986 14 935 were Germans from Russia (29.9%) and children of Turkish origin (28.2%). Age (mean ± s.d.; years) 12.7 ± 3.0 8.9 ± 5.0 In our analysis, we included 14 935 normal-weight children/adolescents of Sex (%; male) 46 51 the KiGGS study. Ethnic group (n) Inclusion and exclusion criteria for the sample German 19 125 11 437 In both studies, only children/adolescents aged 0–18 years (APV) and 0–17 Turkish 1496 426 Southern Europe 524 191 years (KiGGS) from three different ethnic groups (Central European: Weight (mean ± s.d.; kg) 78.8 ± 24.7 32.9 ± 18.3 Germany, Austria, Switzerland; Southeastern European: Turkey; Southern Height (mean ± s.d.; cm) 158.4 ± 14.8 131.3 ± 31.6 European: Spain, Portugal, Italy, Greece, Cyprus, Malta) were included if BMI (mean ± s.d.) 30.6 ± 5.8 17.3 ± 2.5 both parents were from one of the mentioned countries. Patients from the BMI-SDS (mean ± s.d.) 2.5 ± 0.63 − 0.1 ± 0.8 APV database were included if they were overweight or obese. From the KiGGS survey only normal-weight children/adolescents were included. For Frequency (%) the present analysis, we excluded in both studies children with parents Normal weight 4 100 from other ethnic groups, as their numbers in the APV database would be Overweight 30 0 too small for separate analysis. Children with missing information on Obesity 53 0 anthropometric measurements, BP, lipid levels and migration background, Extreme Obesity 13 0 as well as youths taking medications that altered BP pressure or lipid levels were also excluded in both surveys. Abbreviations: APV, Prospective Documentation of Overweight Children and Adolescents; BMI, body mass index; HDL, high-density lipoprotein; Physical and laboratory examination LDL, low-density lipoprotein; KiGGS, German Health Interview and Examination Survey for Children and Adolescents; SDS, standard In both surveys, data on gender, date of birth, migration background, deviation score. height, weight, BP and lipid profiles were recorded. In the APV cohort,

Table 2. Unadjusted prevalence of hypertension and dyslipidemia among overweight/obese patients (APV) and normal-weight subjects (KiGGS)

APV All (n = 25 986) German/Austrian/Swiss (n = 19 125) Turkish (n = 1496) Southern European (n = 524)

Hypertension (%) 40 39 46 46 Total cholesterol 45.18 mmol l − 1 (%) 14 14 14 17 LDL-cholesterol 43.4 mmol l − 1 (%) 14 14 15 17 HDL-cholesterol o0.9 mmol l − 1 (%) 10 10 11 13 Triglycerides 41.71 mmol l − 1 (%) 13 13 15 13

KiGGS All (n = 14 935) German/Austrian/Swiss (n = 11 437) Turkish (n = 426) Southern European (n = 191)

Hypertension (%) 6 6 5 6 Total cholesterol 45.18 mmol l − 1 (%) 9 9 7 7 LDL-cholesterol 43.4 mmol l − 1 (%) 7 7 7 7 HDL-cholesterol o0.9 mmol l − 1 (%) 3 3 4 5 Triglycerides 41.71 mmol l − 1 (%) 2 16 10 10

Abbreviations: APV, Prospective Documentation of Overweight Children and Adolescents; CI, conﬁdence interval; BMI, body mass index; HDL, high-density lipoprotein; LDL, low-density lipoprotein; KiGGS, German Health Interview and Examination Survey for Children and Adolescents; SDS, standard deviation score.

biological parents were born in Germany/Austria/Swiss, Turkey or Spain/ Table 3. ORs and 95% CIa adjusted for age, gender and BMI category Portugal/Italy/Greece/Cyprus/Malta, respectively. among obese/overweight patients (APV) and normal-weight subjects (KiGGS) Statistical analyses Statistical evaluation was performed using SAS version 9.4 (SAS Institute Turkish aOR Southern European Inc., Cary, NC, USA). Descriptive statistics report the number and (95% CI) aOR (95% CI) percentage of subjects with cardiovascular risk factors in both cohorts. Statistical differences between the selected APV study population and the APV Hypertension 1.14 (1.02–1.27) 1.19 (0.99–1.42) – − entire APV population was tested, using Kruskal Wallis for continuous Total cholesterol 45.18 mmol l 1 1.01 (0.87–1.18) 1.20 (0.95–1.52) 2 variables and χ for categorical data. Bonferroni was used to correct for LDL-cholesterol 43.4 mmol l − 1 1.06 (0.91–1.24) 1.21 (0.95–1.54) multiple testing. Age-, gender- and, in case of APV patients, BMI-SDS- HDL-cholesterol o0.9 mmoll − 1 1.00 (0.82–1.16) 1.21 (0.93–1.58) adjusted least-square means were calculated for BP and lipid values using Triglycerides 41.71 mmol l − 1 1.12 (0.96–1.29) 0.95 (0.73–1.23) logistic regression modeling. To adjust for multiple comparisons, the Tukey–Kramer method was used. A probability value of o0.05 was KiGGS fi Hypertension 0.92 (0.58–1.46) 1.07 (0.58–1.98) considered signi cant. Total cholesterol 45.18 mmol l − 1 0.75 (0.49–1.16) 0.80 (0.43–1.50) LDL-cholesterol 43.4 mmol l − 1 0.99 (0.64–1.52) 1.05 (0.57–1.96) HDL-cholesterol o0.9 mmol l − 1 1.51 (0.89–2.58) 1.66 (0.77–3.59) RESULTS Triglycerides 41.71 mmol l −1 0.54 (0.37–0.77) 0.55 (0.32–0.94) Description of subjects Abbreviations: aOR, adjusted odds ratio; APV, Prospective Documentation Obese/overweight patients (APV). In total, 25 986 overweight/ of Overweight Children and Adolescents; BMI, body mass index; HDL, high- obese children/adolescents (mean age ± s.d.: 12.7 ± 3.0 years; 46% density lipoprotein; LDL, low-density lipoprotein; KiGGS, German Health a males) from 126 APV obesity care centers participated in the Interview and Examination Survey for Children and Adolescents. Refer- study. A total of 1496 of the children was Turkish, 524 patients ence category: German/Austrian/Swiss. were Southern European and 19 125 were German, Austrian or Swiss patients. On average, 30% of patients were classified as and the moderate differences between groups, we consider the overweight, 53% as obese and 13% as extremely obese. Mean BMI, analysis of the patients included to be valid. mean BMI-SDS and mean body weight were 30.6 ± 5.8, 2.5 ± 0.6 and 78.7 ± 24.7 kg, respectively. Normal-weight subjects (KiGGS). In the KiGGS survey, 14 935 In some of the outpatient clinics, wait times for new patient's normal-weight (BMI o90th percentile) children/adolescents appointments can be quite long. In some cases, children/ (mean age: 8.9 ± 5.0; 51% males) were analyzed. A total of 426 adolescent were overweight at the time of referral and reduced weight until they were seen for initial evaluation at the outpatient of the subjects were Turkish, 191 subjects were Southern clinic. Nevertheless, these patients were included in our analysis European and 11 437 were German, Austrian or Swiss subjects because of cardiovascular risk in family history and/or signs of (Table 1). metabolic syndrome in previous examinations. This is why a total of 4.0% were normal weight based on German references (Table 1). Prevalence of hypertension and dyslipidemia in relation to The study group differed from the entire APV cohort with ethnicity regard to age and cardiovascular risk profile. Patients not included Overweight/obese patients (APV). Unadjusted prevalence of in the study were younger (12.6 ± 3.8 vs 12.7 ± 3.0 years; hypertension and dyslipidemia according to ethnic group are Po0.001), showed lower BMI-SDS (2.5 ± 0.8 vs 2.5 ± 0.6; shown in Table 2. Po0.001), a lower hypertension prevalence (36% vs In the multiple logistic regression model entering gender, age 40%; Po0.001) and a higher prevalence of LDL-cholesterol 43.4 group, BMI category and ethnicity, the odds ratio of Turkish mmol l − 1 (16% vs 14%; Po0.001), HDL-cholesterol of o0.9- ethnicity and Southern European ethnicity for hypertension was mmol l − 1 (11% vs 10%; Po 0.001) and triglycerides of 4150 1.14 (95% CI: 1.02–1.27; P = 0.044) and 1.19 (95% CI: 0.99–1.42; mg dl − 1 (15% vs 13%; Po0.001). However, due to the cohort size P = 0.14), respectively (Table 3). With regard to lipid parameters, no

© 2015 Macmillan Publishers Limited International Journal of Obesity (2015) 45 – 51 Cardiovascular risk in multiethnic pediatric cohorts L Martin et al 48 significant differences between the three ethnic groups were In the APV cohort (only overweight/obese children), the odds found (Table 3 and Figure 1). ratio for hypertension was higher for Turkish compared with non- migrant children/adolescents, after adjustment for age, gender Normal-weight subjects (KiGGS). Table 2 provides the unadjusted and BMI category. Although there is only limited data on ethnic prevalence of hypertension and dyslipidemia among normal- differences in the prevalence of hypertension among youths living weight subjects (KiGGS) stratified by ethnicity. Analysis of the in Europe, our results are consistent with those of two previous prevalence of hypertension by ethnic subgroups adjusted for sex studies from the Netherlands. The reports showed a higher fi and gender revealed neither signi cant differences between prevalence of hypertension among Turkish obese/overweight normal-weight Turkish and German/Austrian/Swiss subjects (OR: children compared with Dutch native children.14 What the present – 0.919; 95% CI: 0.58 1.5) nor between normal-weight Southern study adds: it is the first known study in Germany to examine the European and German/Austrian/Swiss subjects (OR: 1.07; 95% CI: effect of ethnicity on hypertension in a nationally representative 0.51–2.2) (Table 3 and Figure 2). cohort of normal-weight children/adolescents. For these indivi- As it can be seen in Table 3, normal-weight Turkish children duals, no significant ethnic group differences in the prevalence of showed significantly lower odds of elevated triglyceride levels in hypertension were found. Another important result of our study is comparison with their German/Austrian/Swiss counterparts (OR: fi fi 0.54; 95% CI: 0.37–0.77; P = 0.002). Southern European counter- that we did not nd any signi cant differences in the prevalence parts also showed a slightly, but not significantly, lower of dyslipidemia among the three ethnic groups among the prevalence of high triglycerides compared with their German/ overweight/obese patients. The results of our study on dyslipide- Austrian/Swiss counterparts (9.7% vs 16.4%, P = 0.0703) (Figure 2). mia among normal-weight children/adolescents indicate a higher prevalence of elevated triglycerides among non-migrants. As only a limited number of fasting state blood samples were available for DISCUSSION the normal-weight subjects (KiGGS), this result has to be This is the first report to investigate differences in the prevalence interpreted with caution.24 of hypertension and dyslipidemia among three ethnic groups in Ethnic difference in hypertension prevalence is a scientific large cohorts of overweight/obese and normal-weight children/ challenge. Possible risk factors for hypertension include Western adolescents living in Germany/Austria/Switzerland. lifestyle factors (low physical activity, high salt intake), low

Figure 1. Prevalence of hypertension adjusted for age, gender and BMI category (a), low HDL-cholesterol (b), high LDL-cholesterol (c), high total cholesterol (d) and high triglycerides (e) among overweight/obese children/adolescents (APV) according to ethnicity; Turkish native (white bars), Southern European (light gray bars) and German/Austrian/Swiss (dark gray bars).

Figure 2. Prevalence of hypertension adjusted for age and gender (a), low HDL-cholesterol (b), high LDL-cholesterol (c), high total cholesterol (d) and high triglycerides (e) among normal-weight children/adolescents (KiGGS) according to ethnicity; Turkish native (white bars), Southern European (light gray bars) and German/Austrian/Swiss (dark gray bars). socioeconomic status, low birth weight, genetics and hampered With regard to the association between socioeconomic status access to health care. and cardiovascular risk factors, a recent study investigated the Neither lower socioeconomic status nor genetic characteristics childhood predictors of adult ideal health. Data from three have been shown to fully explain the racial differences in BP seen independent cohort studies from three countries showed that in children.30,31 Genetic ethnic groups vary in the frequency of higher family socioeconomic status was independently associated certain genetic diseases. No ethnic differences were found in with ideal cardiovascular health two to three decades later in 37 overall CVD mortality among first-generation Turks living in adulthood. As immigrants in industrialized countries are more Germany compared with West Germans. At the time of migration, likely to belong to a lower socioeconomic class, they are 38 Turks had a far lower CVD risk than West Germans and it remained predisposed to an increased risk for cardiovascular risk factors. stable over 15 years. This observation does not support the Other risk factors for primary hypertension include low birth weight. Studies have shown that lower birth weight is associated hypothesis of an unfavorable genetic disposition in relation to fi CVD of Turks compared with Germans.32 However, interactions with higher BP in children and adults, although this nding is not consistent across all populations.39 In a recent study of a sample of between genes and environment (epigenetics) may contribute to German children, no significant birth weight differences between excess risk of high BP.33 ‘Thrifty genotypes’ may be the underlying children with a Turkish migration background and native German mechanism of the gene and environmental interactions that 40 34 children were found. contribute to disease susceptibility. Genome-wide association The adaptation of a Western lifestyle after migration is studies (GWAS) have identified several single-nucleotide poly- 35 considered by some as major cause of overweight and develop- morphisms that are associated with the risk of hypertension. A ment of other cardiometabolic risk factors among ethnic minority recent study investigated the effect of obesity on associations of groups. Non-Western migrant populations living in Western the genome-wide association study-identified loci and hyperten- countries are more likely to be physically inactive during leisure sion in Chinese children. Interestingly, a significant association was time than host populations.41 In a study that analyzed the food only found in obese children.36 These recent data reveal a intake of young people with a migration background living in complex pattern of association during childhood for single- Germany, Turkish participants consumed significantly more soft nucleotide polymorphisms modulating cardiometabolic risk fac- drinks, fried potatoes and snacks compared with all other migrant tors that require further investigation. groups and non-migrants.42 Given that energy and sodium intake

© 2015 Macmillan Publishers Limited International Journal of Obesity (2015) 45 – 51 Cardiovascular risk in multiethnic pediatric cohorts L Martin et al 50 are highly correlated,43,44 the Turkish participants assumingly have LIST OF PARTICIPATING CENTERS 45 a high sodium intake. A recent report by Yang et al. examined Amrum Satteldüne Kinder-Reha, Augsburg Bunter Kreis, Bad Frankenhausen Kinder- the association between dietary sodium intake and BP level in Reha, Bad Hersfeld Kinderklinik, Bad Kreuznach Viktoriastift, Bad Kösen Kinder-Reha, children/adolescents. Based on their findings, the authors Bad Neuenahr—DRK Institutsambulanz, Bad Orb Spessartklinik—Kinder-Reha, proposed that overweight/obesity and sodium intake appear to Bensheim Ernährungspraxis, Berchtesgaden CJD, Berchtesgaden Klinik Schönsicht have synergistic effects on the risk for high BP. Kinder-Reha, Berlin Charité Kinderklinik, Berlin Lichtenberg Kinderklinik, Berlin Taken together, further research is needed to increase our Pfundskinder, Berlin Vivantes Beh.Zentrum SPZ, Bonn Ernährungsberatung KIDS understanding of ethnic differences in CVD risk factors. Schulung, Bremen—ZABS, Bremen-Nord Kinderklinik, Bruchweiler Kinder-Reha, Buchholz Ernährungsberatung, Darmstadt Kinderklinik, Datteln Vestische Kinderkli- Strengths and limitations nik, Delmenhorst Kinderklinik, Dinslaken Kinderklinik, Dresden Moby Dick, Düren sozialpäd. Zentrum Marienhospital, Düsseldorf Ernährungsberatung ‘richtig essen’, The strength of our analysis is the large number of obese/ Eschede Adipositastraining KIDS, Essen Kinder und Jugendpsychiatrie, Ettenheim overweight subjects included in this pediatric cohort. The patients Kinderarztpraxis, Euskirchen Kinderarztpraxis, Feldberg ITZ Caritas-Haus, Flensburg presented for treatment at 126 different pediatric obesity centers Fördekids, Frankfurt Päd. Endokrinologie, Freiburg—Fitoc, Freiburg Uni-Kinderklinik, in three different European countries. This setup is likely to reduce Friedrichsdorf Ernährungsberatung, Fürth Kinderklinik, Gaissach Fachklinik Deutsche patient selection. Rentenversicherung Bayern-Süd, Garz Fachklinik CJD, Gauting, Kinderarztpraxis, In addition, we were fortunate to use a large representative Giffers, Ausbildungszentrum Guglera, Gotha Helios Kinderklinik, Gröbenzell Ernäh- sample of normal-weight children and adolescents derived from a rungsinstitut Kinderleicht, Göttingen Uni-Kinderklinik, Göttingen, KIDS Schulungspro- German nationally representative survey. gramm, Hagen Allgemeines Krankenhaus, Hagen Kinderarztpraxis, Hagen However, there are several limitations. Methodologic aspects, Kinderklinik, Hamburg Rallye Energy, Hamburg Wilhelmstift, Hannover Kinderklinik including lab measurements of lipid values, are more difficult to Bult, Haßfurt Adipositasschulung Haßberge, Herrenberg Ernährungsberatung, Hirsch- standardize in a multicenter survey compared with a single-center berg Praxis Maurer, Homburg CJD, Kiel städt. Krankenhaus Fördekids, Korbach study. Among the normal-weight subjects (KiGGS survey), fasting Ernährungsberatung, Krefeld Kinderklinik, Kreischa Klinikum Bavaria Zscheckwitz, state blood samples were not available for all subjects, which has Köln—Amsterdamerstrasse, Power Pänz, Köln MeLo KIDS Schulungsprogramm, Köln to be considered in the interpretation of the results. In addition, Sporthochschule, Kölpinsee, Seebad Klaus Störtebecker Kinder-Reha, Leipzig Uni- only office blood pressure measurements from a single assess- Kinderklinik, Lindau Forum Adipositas e.V., Lingen Bonifatius-Hospital, Lörrach ment, not 24-h profiles, were analyzed. Concerning issues related Elisabethenkrankenhaus, Lörrach Kinderklinik, Lübeck Uni-Kinderklinik, Magdeburg to ethnicity, we are aware that the population of Turkey or Uni-Kinderklinik, Mahlow Programm TRI FIT junior, Menden BIG, Munster Ernährungs- Southern European comprises many different ethnic groups, with & Bewegungsschulung für K&J, Mönchengladbach Städt. Kinderklinik, Mühlhausen different hereditary backgrounds. Another limitation of our study Präventionspraxis Scherf, München Adieupositas, Münster ADI MOBIL, Neunkirchen is its cross-sectional nature, with data from two different cohorts Kinderklinik, Neuss Lukaskrankenhaus, Niederkassel Kinderarztpraxis Sprenker, Norden—Klinik Nordendeich, Oberhausen Adipositaszentrum, Oberstaufen Ernäh- with independent samples. A further limitation of this study was rungsmedizin, Oberstenfeld Ernährungspraxis, Oberstenfeld Ernährungspraxis2, Old- that many potential factors for blood pressure change were not enburg Kids-Schulungsprogramm, Osnabrück christliches Kinderhospital, Overath included in the analysis, such as lifestyle factors and socio- KIDS Schulungsprogramm, Oy-Mittelberg Reha, Paderborn Ernährungspraxis, Passau economic status. Kinderklinik, Pocking Kinderarztpraxis, Poppenricht Ernährungsberatung, Potsdam Patienten Trainings Zentrum, Pönitz FiFaFu KIDS-Programm, Ravensburg Ernährung CONCLUSION und Diät, Rendsburg Villa Schwensen Praxisgemeinschaft KJPP, Ronneburg Ernährungsberatung, Rosenheim Lufti-Team, Rottweil Kinder-Leicht, Rüsselsheim In summary, this study is the first study in Central Europe that Gesundheits- und Pflegezentrum, Salzburg Uni-Kinderklinik, Scheidegg Prinzregent provides ethnic specific prevalences of hypertension and dyslipi- Luitpold Reha, Seebad Heringsdorf—Kinder-Reha, Senden Ernährungsberatung, demia in large obese/overweight and normal-weight pediatric Siegburg KIDS Schulungsprogramm, Siegen DRK Kinderklinik, Simonswald Klinik populations. Turkish obese/overweight children/adolescents Eichhof, Solingen Ernährungsberatung, Sonneberg KIDS Ernährungspraxis, St. Pölten showed a higher prevalence of hypertension relative to their Landesklinikum Kinderklinik, Tholey / SPZ Neunkirchen, Tübingen Universitäts- native German/Austrian/Swiss peers. No significant ethnic differ- Kinderklinik, Ulm Uni-Kinderklinik, Untergruppenbach Ernährungsberatung, Viersen ences were found among normal-weight subjects. Longitudinal Kinderklinik Nikolaus, Villingen-Schwenningen Kiarztpraxis, Waldbröl Gemeinschaft- studies across ethnic groups are needed to (a) further explore the spraxis, Westerland/Sylt, Kinder-Reha, Wien Ernährungsakademie, Wien Uni-Kinderk- causes of the unequal burden of cardiovascular risk factors among linik, Wiesbaden DKD Kinderklinik, Wiesmoor KIDS Schulungsprogramm, Wustrow obese/overweight children/adolescents of different ethnic back- Ostseebad Fischland, Würzburg ambulantes Schulungszentrum. grounds and (b) demonstrate whether our results are congruent with actual risk of future CVD in different ethnic populations. REFERENCES 1 World Health Organization (WHO). Global Status Report on Noncommunicable CONFLICT OF INTEREST Diseases 2010 [Internet]. Geneva, Switzerland: WHO, 2011, 176pp; Available at: http://www.who.int/nmh/publications/ncd_report_full_en.pdf. The authors declare no conflict of interest. 2 Lim SS, Vos T, Flaxman AD, Danaei G, Shibuya K, Adair-Rohani H et al. A comparative risk assessment of burden of disease and injury attributable to 67 risk factors and risk factor clusters in 21 regions, 1990–2010: a systematic ACKNOWLEDGEMENTS analysis for the Global Burden of Disease Study 2010. Lancet 2012; 380: 2224–2260. The APV standardized documentation was supported by grants of the German 3 De Onis M, Blössner M, Borghi E. Global prevalence and trends of overweight and Obesity Society (DAG) and German Federal Centre for Health Education (BZgA). The obesity among preschool children. Am J Clin Nutr. 2010; 92: 1257–1264. ‘ APV Study Group received grant support from the German Competence Network 4 Morrison JA, Friedman LA, Gray-McGuire C. Metabolic syndrome in childhood ’ Adipositas , which is initiated by the German Federal Ministry of Education and predicts adult cardiovascular disease 25 years later: the Princeton Lipid Research Research (grant numbers 01 GI0824 and 01GI1130; APV-LARGE). We are indebted to Clinics Follow-up Study. Pediatrics 2007; 120:340–345. all health professionals of the APV Study Group taking care of overweight children. 5 Juhola J, Oikonen M, Magnussen CG, Mikkilä V, Siitonen N, Jokinen E et al. SW, TR and RWH received grant support from of the German ‘Competence Network Childhood physical, environmental, and genetic predictors of adult Adipositas’, which is supported by the German Federal Ministry of Education and hypertension: the cardiovascular risk in young Finns study. Circulation 2012; 126: Research (grant numbers 01 GI0824 and 01GI1130; APV-LARGE). 402–409.

International Journal of Obesity (2015) 45 – 51 © 2015 Macmillan Publishers Limited Cardiovascular risk in multiethnic pediatric cohorts L Martin et al 51 6 Yusuf S, Reddy S, Ounpuu S, Anand S. Global burden of cardiovascular diseases: different regional German studies (in German). Monatsschr Kinderheilkd 2001; 149: Part II: variations in cardiovascular disease by specific ethnic groups and 807–818. geographic regions and prevention strategies. Circulation 2001; 104: 2855–2864. 26 National High Blood Pressure Education Program Working Group on High Blood 7 Ujcic-Voortman JK, Baan CA, Seidell JC, Verhoeff AP. Obesity and cardiovascular Pressure in Children and Adolescents The fourth report on the diagnosis, disease risk among Turkish and Moroccan migrant groups in Europe: evaluation, and treatment of high blood pressure in children and adolescents. a systematic review. Obes Rev Off J Int Assoc Study Obes 2012; 13:2–16. Pediatrics 2004; 114 (Suppl 4th Report): 555–576. 8 Kurth B-M, Schaffrath Rosario A. The prevalence of overweight and obese children 27 Lurbe E, Cifkova R, Cruickshank JK, Dillon MJ, Ferreira I, Invitti C et al. Management and adolescents living in Germany. Results of the German Health Interview and of high blood pressure in children and adolescents: recommendations of the Examination Survey for Children and Adolescents (KiGGS). Bundesgesundheitsblatt European Society of Hypertension. J Hypertens 2009; 27: 1719–1742. Gesundheitsforschung Gesundheitsschutz 2007; 50: 736–743. 28 Kavey R-EW, Daniels SR, Lauer RM, Atkins DL, Hayman LL, Taubert K et al. 9 Will B, Zeeb H, Baune BT. Overweight and obesity at school entry among migrant American Heart Ass ociation guidelines for primary prevention of atherosclerotic and German children: a cross-sectional study. BMC Public Health 2005; 5: 45. cardiovascular disease beginning in childhood. Circulation 2003; 107: 1562–1566. 10 Fredriks AM, Van Buuren S, Sing RAH, Wit JM, Verloove-Vanhorick SP. Alarming 29 Robert Koch-Institut. Bevölkerungsbezogene Verteilungswerte ausgewählter prevalences of overweight and obesity for children of Turkish, Moroccan and Laborparameter (Gesundheitsberichtserstattung—Beiträge, 2009) [Internet], 2009 Dutch origin in The Netherlands according to international standards. Acta (in German). Available at: http://www.rki.de/DE/Content/Gesundheitsmonitoring/ Paediatr (Oslo, Norway) 2005; 94: 496–498. Gesundheitsberichterstattung/GBEDownloadsB/KiGGS_Laborparameter.pdf 11 Harding S, Whitrow M, Lenguerrand E, Maynard M, Teyhan A, Cruickshank JK et al. (Accessed 28 January 2014). Emergence of ethnic differences in blood pressure in adolescence: the determi- 30 Walker SE, Gurka MJ, Oliver MN, Johns DW, DeBoer MD. Racial/ethnic nants of adolescent social well-being and health study. Hypertension 2010; 55: discrepancies in the metabolic syndrome begin in childhood and persist after 22 1063–1069. adjustment for environmental factors. Nutr Metab Cardiovasc Dis 2012; : – 12 Dannemann A, Ernert A, Rücker P, Bau AM, Martus P, Krude H et al. Ethnicity and 141 148. comorbidities in an overweight and obese multiethnic childhood cohort in Berlin. 31 Dekkers JC, Snieder H, Van Den Oord EJCG, Treiber FA. Moderators of blood Acta Paediatr (Oslo, Norway) 2011; 100:578–584. pressure development from childhood to adulthood: a 10-year longitudinal study. 141 – 13 LA de Hoog M, van Eijsden M, Stronks K, Gemke RJBJ, Vrijkotte TGM. Association J Pediatr 2002; :770 779. between body size and blood pressure in children from different ethnic origins. 32 Razum O, Zeeb H, Gerhardus A. Cardiovascular mortality of Turkish nationals residing in West Germany. Ann Epidemiol 1998; 8: 334–341. Cardiovasc Diabetol 2012; 11: 136. 33 Webster ALH, Yan MS-C, Marsden PA. Epigenetics and cardiovascular disease. Can 14 Van Vliet M, von Rosenstiel IA, Schindhelm RK, Brandjes DPM, Beijnen JH, Diamant M. J Cardiol 2013; 29:46–57. Ethnic differences in cardiometabolic risk profile in an overweight/obese 34 Campbell DD, Parra MV, Duque C, Gallego N, Franco L, Tandon A et al. paediatric cohort in the Netherlands: a cross-sectional study. Cardiovasc Diabetol Amerind ancestry, socioeconomic status and the genetics of type 2 diabetes in a 2009; 8:2. Colombian population. PLoS One 2012; 7: e33570. 15 Reinehr T, Wabitsch M, Andler W, Beyer P, Böttner A, Chen-Stute A et al. Medical 35 Newton-Cheh C, Johnson T, Gateva V, Tobin MD, Bochud M, Coin L et al. care of obese children and adolescents. APV: a standardised multicentre doc- Genome-wide association study identifies eight loci associated with blood umentation derived to study initial presentation and cardiovascular risk factors in pressure. Nat Genet 2009; 41:666–676. patients transferred to specialised treatment institutions. Eur J Pediatr 2004; 163: 36 Xi B, Zhao X, Chandak GR, Shen Y, Cheng HHou D et al. Influence of obesity on 308–312. association between genetic variants identified by genome-wide association 16 Public Use File KiGGS. The German Health Survey for Children and Adolescents studies and hypertension risk in Chinese children. Am J Hypertens 2013; 26 2003–2006. Robert Koch Institute: Berlin, Germany, 2008. 990–996. 17 Kurth B-M. The German Health Interview and Examination Survey for Children and 37 Laitinen TT, Pahkala K, Venn A, Woo JG, Oikonen M, Dwyer T et al. Childhood Adolescents (KiGGS): an overview of its planning, implementation and results lifestyle and clinical determinants of adult ideal cardiovascular health: the taking into account aspects of quality management. Bundesgesundheitsblatt Cardiovascular Risk in Young Finns Study, the Childhood Determinants of Adult 50 – Gesundheitsforschung Gesundheitsschutz 2007; :533 546. Health Study, the Princeton Follow-up Study. Int J Cardiol 2013; 169:126–132. 18 Schenk L, Ellert U, Neuhauser H. Children and adolescents in Germany with a 38 Lange D, Plachta-Danielzik S, Landsberg B, Müller MJ. Social inequality, migration, migration background. Methodical aspects in the German Health Interview and and healthy environments as determinants of overweight of children and Examination Survey for Children and Adolescents (KiGGS). Bundesgesundheitsblatt adolescents. Results of the Kiel Obesity Prevention Study (KOPS). Bundesge- 50 – Gesundheitsforschung Gesundheitsschutz 2007; :590 599. sundheitsblatt Gesundheitsforschung Gesundheitsschutz 2010; 53:707–715. 19 Guidelines of the German Working Group of Childhood Obesity (in German). 39 Law CM, Shiell AW, Newsome CA, Syddall HE, Shinebourne EA, Fayers PM et al. Available at: http://www.a-g-a.de (Accessed 26 January 2014). Fetal, infant, and childhood growth and adult blood pressure: a longitudinal study 20 Kurth B-M, Kamtsiuris P, Hölling H, Schlaud M, Dölle R, Ellert U et al. The challenge from birth to 22 years of age. Circulation 2002; 105:1088–1092. ’ of comprehensively mapping children s health in a nation-wide health survey: 40 Reeske A, Spallek J, Bammann K, Eiben G, De Henauw S, Kourides Y et al. Migrant design of the German KiGGS-Study. BMC Public Health 2008; 8: 196. background and weight gain in early infancy: results from the German study 21 Guidelines of the German Hypertension League (in German). Available at: http:// sample of the IDEFICS study. PLoS One 2013; 8: e60648. www.hochdruckliga.de. (Accessed 26 January 2014). 41 Hosper K, Klazinga NS, Stronks K. Acculturation does not necessarily lead to 22 Neuhauser H, Thamm M. Blood pressure measurement in the German Health increased physical activity during leisure time: a cross-sectional study among Interview and Examination Survey for Children and Adolescents (KiGGS). Meth- Turkish young people in the Netherlands. BMC Public Health 2007; 7: 230. odology and initial results. Bundesgesundheitsblatt Gesundheitsforschung Gesund- 42 Kleiser C, Mensink GBM, Neuhauser H, Schenk L, Kurth B-M. Food intake of young heitsschutz 2007; 50: 728–735. people with a migration background living in Germany. Public Health Nutr 2010; 23 Bundesärztekammer. Richtlinie der Bundesärztekammer zur Qualitätssicherung labor- 13:324–330. atoriumsmedizinischer Untersuchungen. Dtsch Ärztebl 2008; 105: A-341/B-305/C-301. 43 Grimes CA, Riddell LJ, Campbell KJ, Nowson CA. Dietary salt intake, sugar- 24 Thierfelder W, Dortschy R, Hintzpeter B, Kahl H, Scheidt-Nave C. Biochemical sweetened beverage consumption, and obesity risk. Pediatrics 2013; 131:14–21. measures in the German Health Interview and Examination Survey for Children 44 Mulder KA, Zibrik L, Innis SM. High dietary sodium intake among young children and Adolescents (KiGGS). Bundesgesundheitsblatt Gesundheitsforschung Gesund- in Vancouver, British Columbia. J Am Coll Nutr 2011; 30:73–78. heitsschutz 2007; 50: 757–770. 45 Yang Q, Zhang Z, Kuklina EV, Fang J, Ayala C, Hong Y et al. Sodium intake and 25 Kromeyer-Hauschild K, Wabitsch M, Kunze D, Geller F, Geiß HC, Hesse V et al. blood pressure among US children and adolescents. Pediatrics 2012; 130: Percentiles of body mass index in children and adolescents evaluated from 611–619.