Prevalence of overweight and obesity in East and West German children in the decade after reunification: population-based series of cross-sectional studies

Trends of overweight and obesity among preschool children from 2013 to 2018: a cross-sectional study in Rhine-Neckar County and the City of Heidelberg, Germany

BACKGROUND

Early childhood overweight and obesity is a growing public health concern worldwide. Few recent studies have addressed how time trends varied by sociodemographic characteristics at the regional level using large and high-quality data. This study determines how time trends vary in the prevalence of early childhood overweight and obesity by age, gender, and migration background at the regional level.

METHODS

We used a Kernel-density curve to describe the BMI distribution, and evaluated the trends of overweight and obesity by age, gender, and migration background using logistic regression.

RESULTS

Mean BMI and the overall prevalence of overweight and obesity increased among preschool children aged 4-6 years in the Rhine-Neckar County and the City of Heidelberg. After adjusting for age, sex, and migration background, trends of overweight significantly increased only among male children in the age 5 year group with migration background (P < 0.05), and an upward trend of obesity was observed only among male children in the age 5 year group and female children in the age 6 year group with migration background (P < 0.05).

CONCLUSIONS

BMI distribution as well as general prevalence of overweight and obesity are still increasing among preschool children. Children with migration backgrounds, particularly male children in the age 5 year groups and female children in the age 6 year group should be prioritized. Health promotion strategies for children with migration backgrounds will help address this challenge.

What can reunification of East and West Germany tell us about the cause of the allergy epidemic?

The increase of allergies in East Germany--reaching West German prevalence shortly after the reunification--is considered a model for the allergy epidemic in the western world. Whether such a pattern was observed in all comparison studies and for all allergic manifestations is not known because a complete overview is missing. Hints about possible causal factors for the allergy epidemic could be gained by identifying known risk factors, which explain the observed pattern of allergy development in Germany. Again, an overview about these efforts is missing. We identified 14 cross-sectional studies conducted after 1989 and calculated prevalence ratios (West/East) for asthma, hayfever, eczema and allergic sensitization. Additionally, a tabular overview about the explanatory power of risk factors hypothesized in the nineties and covering outdoor exposure, indoor factors, early childhood influences, nutrition as well as awareness is given. At the time of the German reunification, the prevalence ratio West/East was largest for hayfever and sensitization to birch pollen, less pronounced for the other phenotypes and even less than one for atopic eczema. Hayfever and sensitization to birch pollen also showed the steepest increase in East Germany afterwards. Single-room heating with fossil fuels and living as only child in a family were identified as explaining up to 23.5% of the excess trend in East compared to the trend in West. Hayfever as most typical atopic disease showed the difference in allergy pattern between East and West Germany clearest. Risk factors identified for these phenotypes are completely different (single child) or even act in the opposite direction (single-room heating) from classical risk factors for airway diseases. This might be the most important lesson from the West/East German experience. It already stimulated many other studies focussing on protective factors such as microbial stimulation.

The Duration of Breastfeeding and Its Association with Metabolic Syndrome among Obese Children

Objective. The objective of this study was to evaluate whether duration of breastfeeding is associated with a lower prevalence of metabolic syndrome in obese children. Methods. A retrospective analysis of obese children aged 3 to 18 years followed at a pediatric outpatient clinic at a single center between the years 2008 and 2012. The children were divided according to their breastfeeding duration: no breastfeeding, a short period of breastfeeding, and a long term breastfeeding. Also, they were divided into metabolic and nonmetabolic syndrome groups, based on physical examination and laboratory tests. Results. Out of 4642 children who visited the clinic, 123 were obese and were included in the study. About half of them matched the metabolic syndrome criteria. There was no correlation between the prevalence of metabolic syndrome and the duration of breastfeeding. Hypertension, abnormal low levels of HDL, high levels of HbA1c, and high fasting triglyceride levels were very common in our study population, yet no statistical significance was noted among the different breastfeeding groups. Conclusion. In this study, breastfeeding was not associated with a reduced risk for metabolic syndrome, compared with formula feeding, in children who are obese.

Effectiveness of school-based intervention programs in reducing prevalence of overweight

Objectives:

To assess the effectiveness of school-based interventions program in reducing the prevalence of overweight or obesity among schoolchildren.

Data source:

Ovid Medline (1950-December 2012), Embase (1980-2012), CINAHL (1982-2012), secondary references, review articles, and expert in the field.

Study selection:

All published clinical trials were eligible for study if were randomized, methodologically strong-based on a validity assessment, aimed to evaluate a school-based intervention for childhood overweight or obesity, and measured outcome in term of prevalence/incidence difference in overweight and obesity among both groups. Studies involved in cost-effective analysis of school-based intervention have been excluded. Data from eligible studies abstracted and pooled for relative risk.

Results:

Five trials with 3,904 schoolchildren were included. Mean age of the students (boys and girls) ranges 8.6-12.6 years. Meta-analysis showed a statistical significance beneficial effect of school-based intervention programs on obesity status of schoolchildren (risk ratio (RR) 0.58, 95% confidence interval (CI) 0.43-0.78) and suggested 42% reduction in prevalence of obesity among schoolchildren through school-based intervention programs. Individual studies also showed effectiveness of these school-based interventions.

Conclusion:

School-based intervention programs are effective in prevention of childhood overweight and obesity problem and our results quantitatively supported this argument.

Is the different time trend (1997-2008) of the obesity prevalence among adults in the three Belgian regions associated with lifestyle changes?

Background

Obesity is a major public health issue with increasing prevalence among adults. However, in Belgium the regional time trends (1997–2008) differed: the prevalence of obesity increased in the Flemish and Brussels Regions, but remained stable in the Walloon Region, the latter still showing the highest prevalence. The purpose of the present study is to explore if the different time trends of obesity prevalence in the three Belgian regions is associated with lifestyle changes.

Methods

We used data from four successive cross-sectional waves (1997, 2001, 2004 and 2008) of the Belgian Health Interview Survey. The study was restricted to the adult population, resulting in samples of respectively 8,071, 9,391, 10,319 and 8,831 individuals. In line with the WHO definition, obesity was defined as having a BMI ≥ 30. Differences in regional trends of obesity were investigated through stratified analyses. The association between obesity and survey year, adjusted for lifestyle factors (alcohol consumption, smoking, fruit and vegetables consumption and leisure time physical activity), was assessed via logistic regression models. Interactions were added to the models to explore if the association between lifestyle factors and obesity varied over time.

Results

Obesity was associated with daily alcohol use in the Brussels (OR 0.66, 95% CI 0.50-0.88) and Walloon Regions (OR 0.8, 95% CI 0.6-0.9), with lower tendencies of being obese for daily drinkers. The probability of being obese was lower among smokers in the Flemish (OR 0.7, 95% CI 0.6-0.8) and Walloon Regions (OR 0.7, 95% CI 0.6-0.9) than among non-smokers. A lack of leisure time physical activity was associated with the probability of being obese in all regions (Brussels Region: OR 1.6, 95% CI 1.3-1.8; Flemish Region: OR 1.6, 95% CI 1.4-1.9; Walloon Region: OR 1.8, 95% CT 1.6-2.1). This association decreased significantly between 1997 and 2008 only in the Walloon Region.

Conclusion

The decreasing association between obesity and a lack of leisure time physical activity in the Walloon Region between 1997 and 2008 could indicate that there is an increasing awareness of risk factors for obesity in the Walloon population, which may have resulted in a more favourable evolution of the obesity epidemic.

Does school-based physical activity decrease overweight and obesity in children aged 6-9 years? A two-year non-randomized longitudinal intervention study in the Czech Republic

Background

Globally, efforts aimed at the prevention of childhood obesity have led to the implementation of a range of school-based interventions. This study assessed whether augmenting physical activity (PA) within the school setting resulted in increased daily PA and decreased overweight/obesity levels in 6-9-year-old children.

Methods

Across the first to third primary school years, PA of 84 girls and 92 boys was objectively monitored five times (each for seven successive days) using Yamax pedometer (step counts) and Caltrac accelerometer (activity energy expenditure AEE - kcal/kg per day). Four schools were selected to participate in the research (2 intervention, 2 controls), comprising intervention (43 girls, 45 boys) and control children (41 girls, 47 boys). The study was non-randomized and the intervention schools were selected on the basis of existing PA-conducive environment. Analyses of variance (ANOVA) for repeated measures examined the PA programme and gender effects on the step counts and AEE. Logistic regression (Enter method) determined the obesity and overweight occurrence prospect over the course of implementation of the PA intervention.

Results

There was a significant increase of school-based PA during schooldays in intervention children (from ≈ 1718 to ≈ 3247 steps per day; and from 2.1 to ≈ 3.6 Kcal/Kg per day) in comparison with the control children. Increased school-based PA of intervention children during schooldays contributed to them achieving >10,500 steps and >10.5 Kcal/Kg per school day across the 2 years of the study, and resulted in a stop of the decline in PA levels that is known to be associated with the increasing age of children. Increased school-based PA had also positive impact on leisure time PA of schooldays and on PA at weekends of intervention children. One year after the start of the PA intervention, the odds of being overweight or obese in the intervention children was almost three times lower than that of control children (p < 0.005), and these odds steadily decreased with the duration of the intervention.

Conclusions

The findings suggest that school-based PA (Physical Education lessons, PA during short breaks and longer recesses, PA at after-school nursery) in compatible active environments (child-friendly gym and school playground, corridors with movement and playing around corners and for games) has a vital role in obesity and overweight reduction among younger pupils.

The contribution of school breaks to the all-day physical activity of 9- and 10-year-old overweight and non-overweight children

Objectives

This study examines whether moderate-to-vigorous physical activity (MVPA), in at least 30-min school breaks (SB), helps to achieve the health-related amount of daily physical activity (PA) and whether these exercises influence after-school PA.

Methods

The ActiTrainer-based PA was monitored over two school days in 239 children aged from 9 to 10 (57.3% female; 20.1% overweight, and 19.2% obese), in Katowice, in February 2010. PA was assessed based on steps, heart rate, and duration of PA.

Results

MVPA, for 30 min during SB, represented an average of 1,258 steps for overweight girls and 1,620 steps for boys, and 1,336 steps for non-overweight girls and 1,758 steps for boys. Children with 30 min of MVPA during SB attained a higher daily amount of steps (p < 0.001) and duration of overall PA (p < 0.01), in comparison with less physically active children.

Conclusion

The daily 30 min of MVPA during SB amounts to 12.5% of the overall number of steps for girls and 16.3% for boys, thus contributing to higher school PA and overall PA and leading to the achievement of the health-related minimum of PA.

Breastfeeding and body composition in children: will there ever be conclusive empirical evidence for a protective effect against overweight?

An increased prevalence of childhood overweight has been observed worldwide over the past decades, which indicates the need for strategies to prevent obesity. There is some evidence that risk of obesity is primed by exposures early in life. Among other factors, breastfeeding has been hypothesized as a potential priming factor against overweight. Although the properties of human milk suggest possible mechanisms for a protective effect of breastfeeding compared with formula feeding with respect to later overweight, empirical evidence is more difficult to establish. This article reviews the available epidemiologic literature on this topic. Several observational studies have shown evidence for a small protective effect with respect to overweight in childhood. Three meta-analyses reported significant protective effects of breastfeeding against overweight in later life, whereas another meta-analysis showed no effect of breastfeeding on mean body mass index (BMI) after adjustment for confounding factors. These seemingly inconsistent results might potentially be explained by different effects of breastfeeding in normal-weight compared with overweight children. Evidence from interventional studies is limited. A randomized trial failed to confirm an effect of a breastfeeding promotion on children's BMI, but this trial lacked statistical power because rates of breastfeeding were relatively similar in the intervention and control groups. In conclusion, protective priming effects of breastfeeding on later overweight appear to be possible but are difficult to prove. Although observational studies have to deal with confounding issues, interventional studies on breastfeeding promotion may lack power.

Risk factors for obesity: further evidence for stronger effects on overweight children and adolescents compared to normal-weight subjects

BACKGROUND

We recently showed that in preschoolers risk factors for overweight show stronger associations with BMI in children with high BMI values. However, it is unclear whether these findings might also pertain to adolescents.

METHODS

We extracted data on 3-10 year-old (n = 7,237) and 11-17 year-old (n = 5,986) children from a representative cross-sectional German health survey (KiGGS) conducted between 2003 and 2006 and calculated quantile regression models for each age group. We used z-scores of children's body mass index (BMI) as outcome variable and maternal BMI, maternal smoking in pregnancy, low parental socioeconomic status, exclusive formula-feeding and high TV viewing time as explanatory variables.

RESULTS

In both age groups, the estimated effects of all risk factors except formula-feeding on BMI z-score were greatest for children with the highest BMI z-score. The median BMI z-score of 11-17 year-old children with high TV viewing time, for example, was 0.11 [95% CI: 0.03, 0.19] units higher than the median BMI z-score of teenage children with low TV viewing time. This risk factor was associated with an average difference of 0.18 [0.06, 0.30] units at the 90(th) percentile of BMI z-score and of 0.20 [0.07, 0.33] units at the 97(th) percentile.

CONCLUSIONS

We confirmed that risk factors for childhood overweight are associated with greater shifts in the upper parts of the children's BMI distribution than in the middle and lower parts. These findings pertain also to teenagers and might possibly help to explain the secular shift in the upper BMI percentiles in children and adolescents.

[Overweight and obesity in children and adolescents in Germany]

The increasing prevalence of overweight and obesity is a reason for concern not only in Germany but also in other countries. There are various methods and data sources that can be used to assess the extent of this public health problem. The present publication gives an overview of the reference systems that are in use in Germany to assess body mass index (BMI), which is calculated from height and weight, and an overview from several data sources: the school entry examinations, the HBSC study of the WHO, and the German Health Interview and Examination Survey for Children and Adolescents (KiGGS). Current prevalence estimates are based on the KiGGS survey, which found that, based on the Kromeyer-Hauschild reference system, 14.8% of the children and adolescents in Germany aged 2-17 years are overweight, including 6.1% suffering from obesity. In absolute numbers referring to the most recent population numbers, this corresponds to 1.7 million overweight children and adolescents in Germany aged 2 years and older, 750,000 of whom are obese. This description of the status quo represents the benchmark for all future studies of BMI that aim at assessing temporal trends and, thus, the efficacy of national prevention and intervention programs. Regular examinations of certain age groups of children and adolescents in Germany, such as the school entry examinations, can be used for the assessment of temporal trends, if certain standards are followed during the examination. Studies that rely on self-reported height and weight instead of measurements, such as the German part of the HBSC study, however, need a correction based on the subjective body perception. The KiGGS participants themselves are also subject to follow-up interviews and examinations. Thus, it will be possible to regularly update the assessment of the prevalence of overweight and obesity. The Kromeyer-Hauschild reference system should not be replaced by the KiGGS BMI data, in order not to artificially lower the prevalences of overweight and obesity. It should, however, not be used for children below 2 years of age.

Differences in allergy trends between East and West Germany and possible explanations

BACKGROUND

At the time of the German reunification in 1990, manifestations of most allergic diseases were less prevalent in East than in West Germany. It was hypothesized that these East-West differences would diminish with lifestyle and pollution changes in East Germany.

OBJECTIVE

To investigate whether changes in the prevalence of asthma, hayfever, eczema or allergic sensitization in East Germany approached the levels seen in West Germany and to identify possible lifestyle or environmental factors that may influence this.

METHODS

Between 1991 and 2000, 6-year-old children from four areas in East Germany participated in an annual survey. Every 3rd year, a parallel survey was performed in four areas of West Germany. In total, 31 903 children were included. Parents completed a questionnaire regarding lifestyle factors and diagnoses and symptoms of asthma, hayfever and eczema. In sub-areas, eczema was clinically assessed by a dermatologist. Specific IgE sensitization was determined for 6121 children. Logistic regression was used to analyse differences in time trends and the influence of lifestyle and pollution changes.

RESULTS

Lifestyle and pollution changed significantly differently between East and West Germany. The trends in hayfever and in strong (specific IgE >3.5) sensitization against pollen, and particularly birch pollen, were steeper in East than in West Germany. The trend towards marked pollen sensitization was four times stronger (95% confidence interval 1.2-13.9) in East than in West Germany. Increasing numbers of only children, less single-room heating with fossil fuels and increasing importance of traffic-related pollution in East Germany partly explained these differences in time trends.

CONCLUSIONS

Hayfever and sensitization against pollen were the most sensitive allergic manifestations to changes experienced specifically in East Germany. Influences of lifestyle (single-room heating, living as a single child) were important in explaining different trend developments.

Body mass index percentiles for children and adolescents in Germany based on a nationally representative sample (KiGGS 2003-2006)

OBJECTIVE

To present body mass index (BMI) percentiles representative for children in Germany and to compare them with the currently used percentiles by Kromeyer-Hauschild (KH) and international percentiles of the World Health Organisation (WHO) and the International Obesity Task Force (IOTF).

METHODS

Representative examination survey of 17 641 children and adolescents aged 0-17 years living in Germany (KiGGS 2003-2006 study, response rate 67%) with standardized measurement of height and weight.

RESULTS

Generally, BMI in KiGGS was higher than in the reference populations from previous decades. KiGGS shows an asymmetric upward shift of the BMI distribution from about age 6 years and an earlier adiposity rebound compared with KH. The BMI peak in the first year of life is shown by KiGGS and WHO, but much less by KH. The cut-offs for overweight and obesity determined with the IOTF methodology in KiGGS (percentiles corresponding to BMI 25 and 30 kg/m(2) at 18 years of age) were similar to IOTF cut-offs from age 18 to 10 years but systematically lower for younger children.

CONCLUSIONS

The KiGGS BMI percentiles appear more valid for Germany than present alternatives and should be used for population monitoring. Despite their methodological limitations, the general shape of the older German KH references is confirmed by KiGGS for the ages 2-17 years. In order not to obscure the increase in obesity rates in the last decades, we therefore propose to continue using KH for individual diagnosis and estimation of the prevalence of overweight and obesity in this age range.

Risk factors for childhood overweight: shift of the mean body mass index and shift of the upper percentiles: results from a cross-sectional study

BACKGROUND

The worldwide increasing prevalence of childhood overweight seems to be due to an increasing proportion of extremely high body mass index (BMI) values rather than to a shift of the entire BMI distribution. These findings might be attributed to incremental exposure to risk factors particularly affecting overweight children.

OBJECTIVE

To assess the possible differences in associations of several risk factors by subgroups of children's BMI distribution.

METHODS

We applied quantile regression to cross-sectional data on 9698 German preschoolers (5-6 years) collected in 1999 and 2002. Sex- and age-specific BMI standard deviation scores (BMI-SDSs) were used as the outcome variable, and maternal BMI, maternal smoking during pregnancy, exclusive formula feeding, child's weight gain from birth to 2 years of life and low parental education as explanatory variables.

RESULTS

All risk factors except formula feeding contributed to a positive shift in mean BMI-SDS. The estimated effects of all risk factors on BMI-SDS were greatest for children with the highest BMI-SDS value. For example, high television (TV) viewing (>2 h day(-1)) had an effect of 0.46 (95% confidence interval (CI): 0.46, 0.46) SDS units on overweight children (90th percentile), but only a 0.22 (95% CI: 0.11, 0.33) SDS effect on normal-weight children (50th percentile).

CONCLUSIONS

For well-known risk factors of childhood overweight, stronger associations in children with higher BMI values were observed. These findings might possibly help to explain the secular shift in the upper BMI percentiles in children.

Influence of Helicobacter pylori on gastric regulation of food intake

PURPOSE OF REVIEW

To evaluate the influence of Helicobacter pylori infection on the gastric regulation of food intake and body weight.

RECENT FINDINGS

H. pylori infection leads to a decrease of circulating ghrelin through a reduction of ghrelin-producing cells in the gastric mucosa and increases the amount of gastric leptin with no effect on circulating leptin levels. Eradication of H. pylori reverses the abnormal regulation of gastric hormone secretion. This finding is suggested to favor weight gain after H. pylori eradication and points to the potential effect of H. pylori in the pathophysiology of obesity.

SUMMARY

H. pylori has an influence on the release of gastric hormones and therefore plays a role in the regulation of body weight, hunger and satiety.

[Regional differences in the prevalence of overweight and obesity at school entry in Germany : reality or artifact?]

Discovering trends and regional differences in the prevalence of overweight and obesity in children and adolescents is an important task, bearing in mind the high public health relevance of this widespread health risk. It is all the more important to ensure a common methodological basis for the calculations underlying statements about trends and comparisons. Using the data of the German Health Examination Survey for Children and Adolescents (KiGGS), the potential effects of two methodological sources of error when calculating overweight and obesity prevalence at school entry are presented. Finally, simple recommendations for avoiding these errors are given.

Predictors of overweight and obesity in five to seven-year-old children in Germany: results from cross-sectional studies

Background

Childhood obesity is a serious public health problem and epidemiological studies are important to identify predictive factors. It is the aim of this study to analyse factors associated with overweight/obesity in samples of German children.

Methods

35,434 five to seven year-old children (50.9% boys) participated in cross-sectional studies between 1991 and 2000 in several rural and urban areas in East and West Germany. Weight and height were measured and body mass index was calculated. International cut-off points, recommended by the International Obesity Task Force, were used to classify childhood overweight and obesity.

Predictive modelling was employed to analyse independently associated factors, using logistic regression to adjust for confounding.

Results

15.5% were overweight, and 4.3% were obese. Female sex, other than German nationality, smoking in the living place and increasing birth weight were found to increase the odds of overweight and obesity, while increasing educational level, living space > 75 m² and breastfeeding for more than three months were inversely associated.

Conclusion

The findings add to the evidence informing public health action, both through health promotion strategies (promoting breastfeeding, tackling smoking) and wider societal change management (addressing children from migrant families and families with low educational level).