Indicators of overweight and cardiovascular disease risk factors among 11- to 17-year-old boys and girls in Germany

Tracking of serum lipids in healthy children on a year-to-year basis

OBJECTIVES

To assess the stability of lipid profiles throughout childhood and evaluate their onset and dynamic.

MATERIALS AND METHODS

Lipid markers were longitudinally measured in more than 1300 healthy children from the LIFE Child study (Germany) and categorized into normal, at-risk, or adverse. Year-to-year intra-person persistence of the categories during follow-ups was examined and Pearson's correlation coefficient was calculated.

RESULTS

We found strong positive correlations for TC, LDL-C and ApoB (r > 0.75, p < 0.001) from the age of four years. Correlations were lowest during the first two years of life. Most children with normal levels also had normal levels the following year. Children with at-risk levels showed a tendency towards normal levels at the follow-up visit. Adverse levels of TC, LDL-C, ApoB (all ages), and HDL-C (from age 15) persisted in more than half of the affected children. Age-dependent patterns of stability were most pronounced and similar for TC, LDL-C, and ApoB.

CONCLUSIONS

Normal levels of serum lipids show high stability and adverse levels stabilized in early childhood for TC, LDL, and ApoB. At-risk and adverse levels of TC, LDL-C or ApoB may warrant further or repeated diagnostic measurements with regards to preventing CVD in the long run.

Nuchal Skinfold Thickness in Pediatric Brain Tumor Patients

BACKGROUND

Severe obesity and tumor relapse/progression have impact on long-term prognosis in pediatric brain tumor patients.

METHODS

In a cross-sectional study, we analyzed nuchal skinfold thickness (NST) on magnetic-resonance imaging (MRI) follow-up monitoring as a parameter for assessment of nuchal adipose tissue in 177 brain tumor patients (40 World Health Organization (WHO) grade 1-2 brain tumor; 31 grade 3-4 brain tumor; 106 craniopharyngioma), and 53 healthy controls. Furthermore, body mass index (BMI), waist-to-height ratio, caliper-measured skinfold thickness, and blood pressure were analyzed for association with NST.

RESULTS

Craniopharyngioma patients showed higher NST, BMI, waist-to-height ratio, and caliper-measured skinfold thickness when compared to other brain tumors and healthy controls. WHO grade 1-2 brain tumor patients were observed with higher BMI, waist circumference and triceps caliper-measured skinfold thickness when compared to WHO grade 3-4 brain tumor patients. NST correlated with BMI, waist-to-height ratio, and caliper-measured skinfold thickness. NST, BMI and waist-to-height ratio were associated with increased blood pressure. In craniopharyngioma patients with hypothalamic involvement/lesion or gross-total resection, rate and degree of obesity were increased.

CONCLUSIONS

NST could serve as a novel useful marker for regional nuchal adipose tissue. NST is highly associated with body mass and waist-to-height ratio, and easily measurable in routine MRI monitoring of brain tumor patients.

Age, maturation and serum lipid parameters: findings from the German Health Survey for Children and Adolescents

BACKGROUND

Recommendations on preventive lipid screening among children and adolescents remain controversial. The aim of the study was to assess age and puberty-related changes in serum lipids, including total cholesterol (TC), and high-density (HDL-C) and non-high-density lipoprotein cholesterol (Non-HDL-C).

METHODS

Using cross-sectional data from the National Health Interview and Examination Survey for Children and Adolescents in Germany (KiGGS 2003-2006; N = 13,676; 1-17 years), changes in distributions of serum lipids were visualized according to sex, age and maturation. Youth aged 10-17 years were classified as prepubescent, early/mid-puberty, and mature/advanced puberty. Multiple linear regressions were used to quantify the impact of pubertal stage on serum lipid levels, adjusted for potential confounding factors.

RESULTS

Among children 1-9 years mean serum lipid measures increased with age, with higher mean TC and Non-HDL-C among girls than boys. Among children 10-17 years, advanced pubertal stage was independently related to lower lipid measures. Adjusted mean TC, HDL-C and Non-HDL-C was 19.4, 5.9 and 13.6 mg/dL lower among mature/advanced puberty compared to prepubescent boys and 11.0, 4.0 and 7.0 mg/dL lower in mature/advanced puberty compared to prepubescent girls.

CONCLUSIONS

Lipid concentrations undergo considerable and sex-specific changes during physical growth and sexual maturation and significantly differ between pubertal stages. Screening recommendations need to consider the fluctuations of serum lipids during growth and sexual maturation.

Comparison of Two Measurement Devices for Pulse Wave Velocity in Children: Which Tool Is Useful to Detect Vascular Alterations Caused by Overweight?

Vascular alterations may lead to manifest cardiovascular disease in future life. There is a tremendous time delay between the onset and obvious clinical appearance of vascular alterations. Pulse wave velocity (PWV) is one subclinical parameter to detect vascular alterations at a very early stage. Different techniques exist to measure PWV non-invasively as a vascular parameter-all with their own technique-inherent advantages, challenges, and pitfalls. The aim of this study was to compare two techniques to measure PWV, to assess their agreement, and interchangeability. In 780 (♀ = 49.4%) healthy children and adolescents (mean age: 11.61 ± 2.11 years), PWV was obtained with two different techniques. Ultrasound-measured local PWV (PWVβ) at the carotid artery was graphically compared by a Bland-Altman plot with aortic PWV (aPWV), measured oscillometrically on the brachial artery. Reproducibility was assessed with the concordance correlation coefficient by Lin (ρc). Furthermore, participants were categorized by BMI as normal weight (N) or overweight/obese (O) to identify differences in PWVβ and aPWV caused by an increased BMI. Mean PWVβ was lower (4.01 ± 0.44 m/s) than mean aPWV (4.67 ± 0.34 m/s). The two methods differ by mean Δ0.66 ± 0.47 m/s (95% CI: 0.62 to 0.69 m/s; p < 0.001). Bland-Altman analysis indicated the 95% limits of agreement (-0.26 to 1.57) without any evidence of systemic difference. Lin's ρc represented a weak concordance between PWVβ and aPWV (ρc = 0.122; 95% CI: 0.093-0.150). There was no difference in PWVβ between N and O, whereas aPWV was higher in O: 4.81 ± 0.42 m/s than in N: 4.65 ± 0.32 m/s (p < 0.001). The difference, Δ0.16 m/s, 95% CI [-0.25; -0.08], was significant, t ₍₁₂₁₎ = -3.76, p < 0.001, with a medium-sized effect. PWVβ (ultrasound) and aPWV (oscillometry) show a level of disagreement that includes clinically important discrepancies. A discrimination between normal and altered vascular function was possible with aPWV but not with PWVβ.

Validity and intraobserver reliability of three-dimensional scanning compared with conventional anthropometry for children and adolescents from a population-based cohort study

BACKGROUND

Conventional anthropometric measurements are time consuming and require well trained medical staff. To use three-dimensional whole body laser scanning in daily clinical work, validity, and reliability have to be confirmed.

METHODS

We compared a whole body laser scanner with conventional anthropometry in a group of 473 children and adolescents from the Leipzig Research Centre for Civilization Diseases (LIFE-Child). Concordance correlation coefficients (CCC) were calculated separately for sex, weight, and age to assess validity. Overall CCC (OCCC) was used to analyze intraobserver reliability.

RESULTS

Body height and the circumferences of waist, hip, upper arm, and calf had an "excellent" (CCC ≥ 0.9); neck and thigh circumference, a "good" (CCC ≥ 0.7); and head circumference, a "low" (CCC < 0.5) degree of concordance over the complete study population. We observed dependencies of validity on sex, weight, and age. Intraobserver reliability of both techniques is "excellent" (OCCC ≥ 0.9).

CONCLUSION

Scanning is faster, requires less intensive staff training and provides more information. It can be used in an epidemiologic setting with children and adolescents but some measurements should be considered with caution due to reduced agreement with conventional anthropometry.

Nuchal Skinfold Thickness: A Novel Parameter for Assessment of Body Composition in Childhood Craniopharyngioma

CONTEXT

Hypothalamic obesity, cardiovascular disease (CVD), and relapse/progression have a major impact on prognosis in childhood-onset craniopharyngioma (CP). We analyzed nuchal skinfold thickness (NST) on magnetic resonance imaging performed for follow-up monitoring as a novel parameter for body composition (BC) and CVD in CP.

OBJECTIVE

The objective of the study was to identify the association of NST with body mass index (BMI), waist to height ratio (WHtR), functional capacity, and blood pressure (BP) in CP and controls.

DESIGN

This was a cross-sectional and longitudinal prospective study in CP patients.

SETTING

The study was conducted at HIT-Endo, KRANIOPHARYNGEOM 2000/2007.

PATIENTS

Participants included 94 CP patients and 75 controls.

INTERVENTIONS

There were no interventions.

MAIN OUTCOME MEASURES

Association of NST with BC and BP in 43 CP and 43 controls was measured.

RESULTS

NST correlated with BMI SD score (SDS; r = 0.78; P < .001; n = 169) and WHtR (r = 0.85; P < .001; n = 86) in the total cohort and CP patients (NST-BMI SDS: r = 0.77, P < .001, n = 94); NST-WHtR: r = 0.835, P < .001, n=43) and controls (NST-BMI SDS: r = 0.792, P < .001, n = 75; NST-WHtR: r = 0.671, P < .001, n = 43). In CP, systolic BP correlated with NST (r = 0.575, P < .001), BMI SDS (r = 0.434, P = .004), and WHtR (r = 0.386, P = .011). Similar results were observed for diastolic BP in CP. In multivariate analyses, NST had a predictive value for hypertension in postpubertal CP and controls (odds ratio 6.98, 95% confidence interval [1.65, 29.5], P = .008). During a longitudinal follow-up, changes in NST correlated with changes in BMI SDS (P < .001) and WHtR (P = .01) but not with changes in BP and functional capacity.

CONCLUSIONS

Because monitoring of magnetic resonance imaging and BC is essential for follow-up in CP, NST could serve as a novel and clinically relevant parameter for longitudinal assessment of BC and CVD risk in CP.

Biological Maturation, Central Adiposity, and Metabolic Risk in Adolescents: A Mediation Analysis

BACKGROUND

Earlier biological maturation has been related to increased metabolic risk. In this study, we verified mediating effects by central adiposity of the relationship between somatic maturity and metabolic risk factors in adolescents.

METHODS

In a cross-sectional study, 1034 adolescents aged 10-16 years from Londrina/PR/Brazil were evaluated. The age of peak height velocity (PHV) method was used to evaluate somatic maturity. Central adiposity was estimated through waist circumference measurements. Fasting glucose, triglycerides, high-density lipoprotein cholesterol (HDL-C), and blood pressure were measured as metabolic risk indicators. Physical activity (Baecke questionnaire) and cardiorespiratory fitness (20-m shuttle run test) were used as covariates.

RESULTS

Except for fasting glucose, waist circumference showed partial or full mediation of the relationship between maturity and the following metabolic risk factors with their respective z-score values: triglycerides (boys = -3.554 vs. girls = -5.031), HDL-C (boys = +5.300 vs. girls = +5.905), systolic blood pressure (boys = -3.540 vs. girls = -3.763), diastolic blood pressure (boys = -2.967 vs. girls = -3.264), and metabolic risk score (boys = -5.339 vs. girls = -6.362).

CONCLUSIONS

The results suggest that central obesity plays a mediating role in the relationship between somatic maturation and metabolic risk during adolescence.

Índice de massa corporal, circunferência da cintura e hipertensão arterial em estudantes

RESUMO Objetivo: investigar qual o melhor preditor antropométrico de hipertensão arterial em alunos de escolas privadas. Método: estudo transversal, com amostra composta por 286 alunos com idade de 10 a 14 anos de duas escolas privadas de Paranavaí-Paraná. As variáveis analisadas foram: índice de massa corporal, circunferência de cintura e pressão arterial. Na análise estatística foram utilizados os testes de correlação parcial de Pearson e a regressão logística multivariada, considerando-se p<0,05. Resultados: os dois indicadores antropométricos demonstraram fracas correlações com os níveis sistólicos e diastólicos, com coeficientes (r) variando de 0,27 à 0,36 (p< 0,001). Na análise multivariada, o único indicador antropométrico associado ao risco de hipertensão arterial foi a circunferência de cintura (OR= 2,3; IC 95%: 1,1-4,5) independente da idade e gênero. Conclusão: nesta faixa etária, a circunferência de cintura parece ser melhor do que índice de massa corporal como preditor de hipertensão arterial.

Waist-to-height ratio, inflammation and CVD risk in obese children

OBJECTIVE

To evaluate the association between waist-to-height ratio (WHtR) and specific biomarkers of inflammation, CVD risk and endothelial dysfunction in prepubertal obese children.

DESIGN

Prospective, multicentre case-control study matched by age and sex.

SETTING

Children were recruited between May 2007 and May 2010 from primary-care centres and schools in three cities in Spain (Cordoba, Santiago de Compostela and Zaragoza).

SUBJECTS

Four hundred and forty-six (223 normal weight and 223 obese) Caucasian prepubertal children aged 6-12 years.

RESULTS

WHtR was higher in the obese than in the normal-weight children. Blood pressure, waist circumference, weight, height, insulin, plasma lipids, leptin, resistin, abnormal neutrophil and monocyte counts, C-reactive protein, IL-6, IL-8, TNF-α, myeloperoxidase, soluble intercellular adhesion molecule-1, selectin and plasminogen activator inhibitor-1 levels were higher in the obese than in the normal-weight group. Adiponectin and HDL-cholesterol were lower and glucose and metalloproteinase-9 showed no differences. Resistin, TNF-α and active plasminogen activator inhibitor-1 were associated with WHtR, a sensitive indicator of central obesity.

CONCLUSIONS

Our results lead to the hypothesis that changes in biomarker levels of insulin resistance, inflammation and CVD risk before puberty might induce metabolic consequences of obesity in obese children before reaching adulthood.

Is central obesity associated with poorer health and health-related quality of life in primary school children? Cross-sectional results from the Baden-Württemberg Study

BACKGROUND

Childhood obesity and its consequences are a growing threat to national economies and health services. The aim of this study was to determine associations between waist-to-height ratio (WHtR) as a measure of central obesity, and health-related quality of life (HRQoL) and absenteeism of primary school children in the state of Baden-Württemberg, Germany.

METHODS

Cross-sectional data from 1888 first and second grade children (7.1±0.6 years) participating in the baseline measurements of the Baden-Württemberg Study were analyzed. Parents completed questionnaires including a rating of their children's HRQoL using KINDLR and EQ5D-Y VAS. Days of absence because of illness, and number of visits to a physician during the last year of school/kindergarten were asked, as well as the number of days parents took off work to care for their sick child. Anthropometric measurements were taken by trained staff. The Mann-Whitney-U test was used for statistical analysis of differences between WHtR groups. Logistic regression models were used to identify factors associated with sick days.

RESULTS

A total of 158 (8.4%) children were centrally obese (WHtR ≥0.5). These children had significantly more sick days (9.05 vs. 6.84, p < 0.001) and visits to a physician (3.58 vs. 2.91, p < 0.05), but not days of parental absence than other children. According to regression analysis, sick days were also associated with age, migration status, physical activity pattern, maternal health awareness and family education level. Parent-rated HRQoL was significantly lower in centrally obese children for the EQ5D-Y VAS (88.1 vs. 91.6, p < 0.001), and the KINDLR subscales 'school' (79.9 vs. 82.5, p < 0.05) and 'friends' (75.4 vs. 78.3, p < 0.05), but not for the total score.

CONCLUSIONS

Cross-sectional results show higher rates of absence, more visits to a physician and lower HRQoL in children with central obesity. Each missed day at school implies a hazard to academic achievement and each additional visit to a physician is related to higher health care costs. Thus, the negative impact of central obesity is already measurable in primary school children, which emphasizes the urgent need for early delivery of health promotion and targeted prevention.

Abdominal obesity in German adolescents defined by waist-to-height ratio and its association to elevated blood pressure: the KiGGS study

OBJECTIVE

The aim of this study was to compare the fixed 0.5 cut-off and the age- and sex-specific 90th percentile (P90) for waist-to-height ratio (WHtR) in German adolescents with respect to the prevalence of abdominal obesity and to compare the screening ability of WHtR and BMI to identify hypertensive blood pressure (BP) values.

METHODS

Between 2003 and 2006, the German Health Interview and Examination Survey for Children and Adolescents (KiGGS) was carried out including 3,492 boys and 3,321 girls aged 11-17 years. Abdominal obesity was assessed by two WHtR cut-points (P90; 0.5). Hypertensive BP was defined as BP exceeding age-, sex- and height-specific 95th percentiles or the adult threshold for hypertension (140/90 mm Hg).

RESULTS

Agreement between the WHtR cut-offs was very good (Kappa 0.89 for boys; 0.81 for girls), and the prevalence of abdominal obesity was slightly higher using P90 (boys 12.0%; girls 11.3%) compared to 0.5 (boys 10.7%; girls 8.0%). WHtR and BMI-for-age had equivalent ability to discriminate hypertensive BP (ROC-AUC < 0.7; sensitivity of the 0.5 cut-off for detecting hypertensive BP < 30%).

CONCLUSION

The fixed 0.5 WHtR cut-off can be used in German adolescents to characterize abdominal obesity. However, WHtR is not suitable as a screening tool for hypertensive BP in adolescents.