Interrelationships between anthropometric variables and overweight in childhood and adolescence

Waist circumference as a prognostic index of childhood abdominal obesity: findings in the Spanish population

Introduction

Introduction: early detection of childhood obesity plays a crucial role in the prevention of diseases during adulthood. At present, the most commonly used screening tool for detecting overweight/obesity in children is the percentile for age of body mass index, although this rate is unable to provide information about fat distribution. An emerging marker of abdominal fat distribution is waist circumference (WC). Objective: the aim of this study was to evaluate the differences between the different diagnostic criteria available to define overweight and obesity in order to establish the optimal WC cut-off values for the Spanish children population. Methods: a cross-sectional study was carried out in 8,241 schoolchildren aged 3 to 12 years from Villanueva de la Cañada (Madrid, Spain). WC (cm), weight (kg) and height (cm) were measured according to the recommendations of the Society for the Advancement of Kineanthropometry (ISAK). The values obtained for the diagnostic criteria (Spanish Orbegozo Foundation (OF), the International Obesity Task Force (IOTF), and the World Health Organization (WHO) were compared using McNemar's test for paired proportions. The kappa coefficient (κ) was used to assess the degree of agreement of the three classifications. We analyzed the validity of body mass index (BMI) and WC using the receiver operating characteristic (ROC) curve analysis. The Youden index was used to determine cut-off values for WC that identify childhood obesity Results: overweight and obesity prevalences were calculated according to the OF, IOTF, and WHO criteria. There was a "substantial" agreement for the overweight and obesity categories between the Spanish criteria and IOTF (κ = 0.636), while agreement was "slight" between the Spanish criteria and those of WHO (κ = 0.198). The estimated cut-off WC criteria ranged from 54.5 to 88.0, varying according to sex and age. Conclusion: the proposed WC cut-off values, stated for the first time in a young Spanish population, are a simple and valid alternative as diagnostic criteria of abdominal obesity.

Post-2000 growth trajectories in children aged 4-11 years: A review and quantitative analysis

Children's body mass index (BMI) growth trajectories are associated with adult health outcomes, and vary by geography and epoch. Understanding these trajectories could help to identify high risk children and thus support improved health outcomes. In this review, we compare and quantitatively analyse BMI level and trajectory data published since 2010. We characterise recent growth in children aged 4-11 years, an age range most frequently targeted for BMI intervention, yet less studied than young childhood or infancy. Through searches in OVID, we identified 54 relevant texts which describe either post-2000 summary BMI values by age and gender in cohorts with sample sizes of over 1000 children, or the results of latent class analyses of BMI trajectories within the 4-11 year age range. Population level median growth curves were projected and visualised as weighted means. These BMI curves, based on data from 729,692 children, can be visually clustered into 'high' and 'low' charting groups with extreme outlying values. Within populations, latent class analyses converge on 3-4 individual child trajectories, two of which predispose adult overweight. These growth pathways diverge early in childhood, yet are not effectively distinguished via isolated BMI measurements taken between 4 and 11 years, meaning some high risk children may currently be poorly identified.

Associations between different weight-related anthropometric traits and lifestyle factors in Norwegian children and adolescents: A case for measuring skinfolds

OBJECTIVES

The purpose of this study was to investigate the association between weight-related anthropometric measures and children's eating habits, physical activity and sedentary lifestyle at a population level.

METHODS

Data from the Bergen Growth Study were used to study the association of z-scores of waist circumference (WC), weight-to-height ratio (WHtR), subscapularis (SSF) and triceps (TSF) skinfolds and BMI, with lifestyle factors in 3063 Norwegian children (1543 boys) aged 4-15 years, using linear regression analysis. Each sex was analyzed separately.

RESULTS

In a fully adjusted model with additional correction for BMI z-scores, the consumption of vegetables was associated with higher WC (b = 0.03) and TSF (b = 0.05) z-scores in girls. Sedentary behavior was not associated with any of the anthropometric measures. Physical activity was negatively associated with SSF (b = -0.07) and TSF (b = -0.07) z-scores in boys, while a significant negative association was observed with WC (b = -0.02), WHtR (b = -0.03), SSF (b = -0.04) and TSF (b = -0.06) in girls.

CONCLUSION

Physical activity was negatively associated with skinfolds in both sexes. The BMI was not related to the level of physical activity, and should be complemented with direct measures of fat tissue, like skinfolds, when studying the effect of physical activity on body composition in children.

Central overweight and obesity in Polish schoolchildren aged 7-18 years: secular changes of waist circumference between 1966 and 2012

We investigated secular trends of body mass index (BMI) and waist circumference (WC) in Polish schoolchildren examined through a period of almost 50 years. Data on height, weight and WC came from four cross-sectional surveys conducted in Poland between 1966 and 2012, covering 34,005 boys and 34,008 girls. Raw data of BMI and WC were standardized for age classes. Statistical analyses included the Kruskal-Willis test and Pearson Chi-square test. BMI and WC increased during the studied period; however, the growth was higher for WC (increase by 0.56 and 0.44 SD scores for BMI and 1.05 and 0.77 SD scores for WC in boys and girls, respectively). In boys, secular changes in BMI and WC were similar across childhood, early and late adolescence, while in girls they differed, indicating change in the type of adipose tissue distribution to a more central one in late adolescent girls.

CONCLUSION

During 46 years, there was a tendency to a greater increase of the fraction of individuals with central obesity than the overall one. Since abdominal fat deposit is more connected with higher health risks than subcutaneous fat pattern, probably the number of metabolic complications in Polish children and adolescents will intensify in the future. What is Known: • BMI has significant limitations related to fat distribution, while WC is a measure of central adiposity. • Greater central fat deposition increases the risk of many diseases; therefore, WC may serve as a diagnostic measure for detecting central obesity in children at risk. What is New: • In girls, changes in BMI and WC indicate change in adipose tissue distribution to a more central one in late adolescence girls. • Both general and abdominal obesity in Polish children increased significantly from 1966 to 2012, with the tendency to a greater increase of the fraction of individuals with central obesity than the overall one, implying the number of metabolic complications in Polish children and adolescents may intensify in the future.

Body mass index and physical activity in early childhood are associated with atopic sensitization, atopic dermatitis and asthma in later childhood

Background

The results of studies on the associations of childhood excessive weight/obesity and physical activity with atopic sensitization and atopic diseases are inconsistent. We studied the associations of anthropometry and physical activity in childhood with atopic sensitization and atopic diseases in late childhood.

Methods

In a cohort study including cases exposed to preeclampsia during pregnancy and controls, anthropometry and physical activity were assessed at several ages in 617 children. Associations with atopic sensitization and atopic diseases in late childhood were analysed using multiple logistic regression.

Results

Body mass index standard deviation score (BMI SDS) at 1 year and low physical activity at 3–6 years were positively associated with atopic sensitization at 12.8 years [adjusted odds ratio (OR) 1.22; 95 % confidence interval (1.00, 1.49) and OR 2.36; (1.15, 4.81), respectively]. Change in BMI SDS from 1 to 4 years, BMI SDS at 4 years, and high physical activity at 6–10 years were positively associated with atopic dermatitis by 10.8 years [OR 1.46; (1.11, 1.92); OR 1.32; (1.06, 1.65) and OR 1.94; (1.16, 3.24); respectively]. Low physical activity at 3–6 and 6–10 years were positively associated with asthma by 10.8 years [OR 3.61; (1.56, 8.36) and OR 2.52; (1.24, 5.12), respectively].

Conclusions

BMI and physical activity in early childhood were associated with atopic sensitization, atopic dermatitis and asthma in later childhood. Larger cohorts with repeated measurements of both predictors and outcomes are required to further elucidate this issue.

Trial registration Our study was observational without any clinical intervention on the participants. Therefore, no trial registration number is available

Electronic supplementary material

The online version of this article (doi:10.1186/s13601-016-0124-9) contains supplementary material, which is available to authorized users.

Should children with overweight or obesity be excluded from height references?

BACKGROUND AND OBJECTIVES

Growth reference charts are usually based on measurements of children free from a medical condition that affects growth. However, samples collected during the past decades often contain a large proportion of overweight or obese children. Because obesity increases linear growth, the question arises to what extent the percentiles curves for length/height are affected by the presence of children with overweight or obesity.

METHODS

Data from two cross-sectional samples of 2-year-old to 18-year-old children were analysed: 12,252 Belgian children, measured in 2002-2004, and 6159 Norwegian children, measured in 2003-2006. The LMS method was used to estimate height-for-age curves with and without children considered overweight or obese according to the International Obesity Task Force thresholds.

RESULTS

The prevalence of overweight (including obesity) and obesity was 13.0% and 2.8% in the Belgian and 13.8% and 2.3% in the Norwegian sample. Children were taller when overweight (+0.49 and 0.43 SD, in the Belgian and Norwegian sample, respectively) or obese (+0.73 and 0.72 SD in the Belgian and Norwegian sample, respectively). Effect sizes were smaller in younger and older children, which points to an advanced age of maturation as a possible cause. Excluding overweight and obese children had only a minor impact on the growth curves with largest difference in mean height SD scores -0.09 in the Belgian and -0.12 in the Norwegian sample with a corresponding increase of up to 0.5% and 1.2% in number of children >+2 SD.

CONCLUSIONS

Current Belgian and Norwegian growth references for length/height were found to be largely unaffected by the current proportion of overweight and obese children. There is, therefore, no need for revised height charts that exclude overweight or obese children.

Associations between early body mass index trajectories and later metabolic risk factors in European children: the IDEFICS study

Faster growth seems to be a common factor in several hypotheses relating early life exposures to subsequent health. This study aims to investigate the association between body mass index (BMI) trajectories during infancy/childhood and later metabolic risk in order to identify sensitive periods of growth affecting health. In a first step, BMI trajectories of 3301 European children that participated in the multi-centre Identification and Prevention of Dietary and Lifestyle-induced Health Effects in Children and Infants (IDEFICS) study were modelled using linear-spline mixed-effects models. The estimated random coefficients indicating initial subject-specific BMI and rates of change in BMI over time were used as exposure variables in a second step and related to a metabolic syndrome (MetS) score and its single components based on conditional regression models (mean age at outcome assessment: 8.5 years). All exposures under investigation, i.e. BMI at birth, rates of BMI change during infancy (0 to <9 months), early childhood (9 months to <6 years) and later childhood (≥6 years) as well as current BMI z-score were significantly associated with the later MetS score. Associations were strongest for the rate of BMI change in early childhood (1.78 [1.66; 1.90]; β estimate and 99 % confidence interval) and current BMI z-score (1.16 [0.96; 1.38]) and less pronounced for BMI at birth (0.62 [0.47; 0.78]). Results slightly differed with regard to the single metabolic factors. Starting from birth rapid BMI growth, especially in the time window of 9 months to <6 years, is significantly related to later metabolic risk in children. Much of the associations of early BMI growth may further be mediated through the effects on subsequent BMI growth.