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Objective. Gestational weight gain (GWG) has been associated with overweight in offspring. The aim of the study was to assess the association of GWG with childhood overweight and a potential effect modification by maternal BMI. Methods. In a cross-sectional study of 10 784 children aged 3 to 17 years from the German national child health survey (2003-2006), main outcome measure was overweight defined by the criteria of the International Obesity Task Force. Main exposure was GWG in data-derived categories. Results. Crude and adjusted odds ratios (OR) for high and low GWG with average GWG as a reference were calculated in logistic regression models. With adjustment for potential confounders, the OR of childhood overweight for high GWG was 1.16 (95% confidence interval [CI]: 1.02, 1.32), whereas for low GWG the adjusted OR was not significant at 1.01 (95% CI: 0.89, 1.15). Stratified analyses by estimated pre-pregnancy BMI revealed inconsistent effects of high GWG on childhood overweight, with a significantly increased risk for children of normal-weight mothers only. No statistically significant advantageous effect of low GWG was present for any of the maternal BMI subgroups. Conclusion. A high compared with an average GWG accounts for a moderate increase in the risk of offspring overweight, whereas a lower than average GWG does not appear to reduce this risk. Subgroup analyses suggested that the beneficial effect of avoidance of high GWG might be confined to normal-weight mothers. Interventions promoting healthy GWG should not only target overweight and obese, but also normal-weight females.

The objective is to present height-for-age percentiles representative for infants, children, and adolescents in Germany and to compare them with older German height references by Kromeyer-Hauschild which are based on heterogeneous pooled data (KH) and with international growth charts from the Centers for Disease Control (CDC) as well as the growth standard and the growth reference of the World Health Organization (WHO).The reference population consists of a nationally representative sample of 17 079 children and adolescents aged 0-17 years (KiGGS study 2003-2006) with standardized height measurements. Height reference curves were created using Cole's LMS method. To compare KiGGS with other reference systems, KiGGS height values were transformed to SD-scores using the KH, WHO and CDC references.Height-for-age percentiles in KiGGS increase until age 16 years in girls and until the end of the observed age range (17.98 years) for boys. In general, boys are taller than girls, except for the age range 10.5-13.0 years. The difference in height between boys and girls is negligible before puberty and reaches 13 cm at age 17.98 years. KiGGS and KH percentiles differ only slightly. However, there are substantial differences in SD-score levels between KiGGS on the one hand and WHO and CDC on the other hand, KiGGS generally being higher, especially in the extreme percentiles.The KiGGS height-for-age references can be recommended as a national height reference for screening and monitoring growth in infants (starting from 4 months of age), children and adolescents in Germany. In German samples, the WHO and CDC references can be used for international comparisons.

A GROWING BODY OF EVIDENCE THAT SLEEP DURATION AFFECTS WEIGHT STATUS IN CHILDREN HAS BEEN SUMMARIZED IN 3 RECENT REVIEWS.1–3 A meta-analysis by Chen and colleagues calculated a 9% decrease in overweight/obesity risk for a one-hour increase in sleep duration in children up to 10 years of age. There is still considerable variability in the effects reported by different individual studies, which could be explained by different ages included. This issue has never been systematically assessed in publications the authors are aware of. The majority of studies use measures of overweight/obesity risk, while BMI is reported less frequently. The changes in BMI distributions have merely been addressed, although they might have implications for choosing the appropriate outcome measure and are interesting for physiological and epidemiological reasons. Furthermore, there is limited evidence on whether sleep duration is linked to body fat in children.4–6 A more detailed analysis of epidemiological data with respect to these issues may have implications for further research regarding underlying physiological mechanisms. The aims of this study were to describe the sleep duration typical for children 3 to 10 years of age in a nationally representative sample to assess whether the effects of sleep duration on body mass are age dependent to investigate if these effects are also seen on body fat (KFA) as outcome to analyze how the distribution of BMI and KFA is changed in relation to sleep duration

Despite a growing interest in the epidemiology of paediatric hypertension, data on how often blood pressure in children and adolescents already exceeds adult thresholds for optimal blood pressure are scarce. The aim of this study was to estimate the prevalence of higher-than-optimal and hypertensive blood pressure values according to adult cutoffs in an unselected representative sample of children and adolescents living in Germany.Standardized oscillometric blood pressure measurements were performed in 14 730 children aged 3-17 years (7203 girls and 7527 boys) participating in a nationally representative examination survey of children and adolescents living in Germany (The German Health Interview and Examination Survey for Children and Adolescents, KiGGS, response rate 67%). The mean of two measurements was used for this analysis.The prevalences of higher-than-optimal blood pressure values by adult criteria (or=120/80 mmHg) increased with age and was 52.2% in boys aged 14-17 years and 26.2% in girls aged 14-17 years (including 6.0% of boys and 1.4% of girls with hypertensive valuesor=140/90 mmHg). More than half of these adolescents with nonoptimal blood pressure values had additional cardiovascular risk factors (overweight defined as body mass indexor=90th percentile for sex and age, dyslipidaemia defined as total cholesterol5.0 mmol/l or high-density lipoprotein cholesterol less than 1.0 mmol/l or smoking).These results suggest the need for routine blood pressure measurements in children and adolescents as required by clinical guidelines, for more attention to coexisting other cardiovascular risk factors and for a sustained focus on healthy lifestyles that can be learned best at a young age.

There are virtually no prospective cohort studies in Germany regarding the changes of menopausal hormone therapy (HT) use pattern and factors associated with HT discontinuation after the release of the Women's Health Initiative (WHI) trial results.We assessed HT prevalence and use pattern as well as factors associated with HT discontinuation in a cohort of 903 women 40 years of age and older, who participated in two consecutive follow-up visits in a 20-year prospective health study from July 2000 to February and from August 2002 to December 2004.Overall, the prevalence of HT users in the cohort declined significantly from 35.4% in 2000-2002 to 22.5% in 2002-2004. Adjusting for aging of the population, a statistically significant decrease in HT user prevalence was consistently observed across subgroups of HT users defined by type and duration of HT use. The decline was most pronounced with respect to women using combined estrogen-progestin regimens (-10.5%), higher-dose estrogens (-11.6%), oral preparations (-11.1%), as well as long-term HT users (-8.4%). The prevalence of women indicating HT use for climacteric symptoms decreased significantly (-12.4%), whereas the prevalence of women reporting use of HT for the prevention of osteoporosis increased (+1.8%) significantly. Irrespective of hysterectomy status, half of the women who continued HT changed their HT preparations and switched to lower estrogen doses (11.5%), topical estrogens (8.2%), or phytohormones (3.8%). We did not observe any significant differences between women who continued and discontinued HT regarding health-related characteristics of the study population as of 2000-2002. However, women seeing a gynecologist in the 12 months preceding the 2002-2004 visit were significantly less likely to discontinue HT use in bivariate and multivariate analyses.Substantial declines in HT user prevalence as well as changes in HT use patterns to lower-dose estrogen preparations and non-oral routes of administration are likely to reflect effects of the publication of the WHI results. Consulting a gynecologist appeared to be relevant for a woman's decision to continue HT.

Unfortunately, the original version of this article [1] contained an error. The spelling of the author [Anna-Kristin Brettschneidera] name was incorrect. This has been corrected above and also included correctly below: Anna-Kristin Brettschneider

The German Health Interview and Examination Survey for Children and Adolescents (KiGGS) was conducted from May 2003 to May 2006 by the Robert Koch Institute in 167 communities representative of Germany. By collecting comprehensive and nationally representative data on the health status of children and adolescents aged 0 to 17 years, the study aimed to fill a longstanding evidence gap. Data from 17,641 study participants will be analysed in a timely and systematic manner by the Robert Koch Institute. Initially mainly descriptive analyses as presented in the current special issue on the KiGGS study, provide information on the distribution of main health characteristics according to sociodemographic key variables, including age, sex, region of residence (former East/West Germany), social status, and migrant background. We report here the rationale for a standard set of stratifying variables and the operationalisation of composite variables. Furthermore, we illustrate the public health relevance of the observed group differences using the example of an important health indicator: parents' evaluation of their children's general state of health.

Ambient air pollution has been associated with an increased risk of hospital admission and mortality in potentially susceptible subpopulations, including myocardial infarction (MI) survivors. The multicenter epidemiological study described in this report was set up to study the role of air pollution in eliciting inflammation in MI survivors in six European cities, Helsinki, Stockholm, Augsburg, Rome, Barcelona, and Athens. Outcomes of interest are plasma concentrations of the proinflammatory cytokine interleukin 6 (IL-6) and the acute-phase proteins C-reactive protein (CRP) and fibrinogen. In addition, the study was designed to assess the role of candidate gene polymorphisms hypothesized to lead to a modification of the short-term effects of ambient air pollution. In total, 1003 MI survivors were recruited and assessed with at least 2 repeated clinic visits without any signs of infections. In total, 5813 blood samples were collected, equivalent to an average of 5.8 repeated clinic visits per subject (97% of the scheduled 6 repeated visits). Subjects across the six cities varied with respect to risk factor profiles. Most of the subjects were nonsmokers, but light smokers were included in Rome, Barcelona, and Athens. Substantial inter- and intraindividual variability was observed for IL-6 and CRP. The study will permit assessing the role of cardiovascular disease risk factors, including ambient air pollution and genetic polymorphisms in candidate genes, in determining the inter- and the intraindividual variability in plasma IL-6, CRP, and fibrinogen concentrations in MI survivors.

CMV seroprevalence increases with age and is significantly associated with migration background, country of origin, and place of birth. We identified the birth order of siblings, breastfeeding, early day care attendance and living in East Germany as further risk factors., Background. Congenital cytomegalovirus (CMV) infection can cause severe birth defects. The majority of children with congenital CMV are born to CMV-seropositive women; however, transmission from mother to fetus and resulting defects are more likely to occur when mothers experience seroconversion during pregnancy. The objective of this study was to provide a population-based estimate of CMV seropositivity and to identify factors that correlate with the detection of CMV-immunoglobulin (Ig)G antibodies. Methods. Cytomegalovirus-specific IgG antibodies were determined by enzyme-linked immunosorbent assay in 13 876 serum samples from children and adolescents (aged 1–17 years). Cytomegalovirus seroprevalence was correlated with children's age, gender, migration background, country of origin, place of birth, socioeconomic status, breast feeding, daycare attendance, order and number of siblings, and residence in East versus West Germany. Results. Age-adjusted seroprevalence was 27.4% (95% confidence interval, 25.8–29.0). Cytomegalovirus seroprevalence increased with age (21.5% at ages 1–2; 32.0% at ages 14–17). Cytomegalovirus seropositivity was significantly associated with migration background, country of origin and place of birth, and (among migrants only) with low socioeconomic status. Risk factors for CMV acquisition included the birth order of siblings, breastfeeding, early daycare attendance, and living in East Germany. Conclusions. In Germany, CMV seroprevalence increases with age, irrespective of gender. These data highlight risk factors associated with seroprevalence and help to identify a target age for the application of a CMV vaccine.

Background The nationwide “German Health Interview and Examination Survey for Children and Adolescents” (KiGGS), conducted in 2003–2006, showed an increase in the prevalence rates of overweight and obesity compared to the early 1990s, indicating the need for regularly monitoring. Recently, a follow-up—KiGGS Wave 1 (2009–2012)—was carried out as a telephone-based survey, providing self-reported height and weight. Since self-reports lead to a bias in prevalence rates of weight status, a correction is needed. The aim of the present study is to obtain updated prevalence rates for overweight and obesity for 11- to 17-year olds living in Germany after correction for bias in self-reports. Methods In KiGGS Wave 1, self-reported height and weight were collected from 4948 adolescents during a telephone interview. Participants were also asked about their body perception. From a subsample of KiGGS Wave 1 participants, measurements for height and weight were collected in a physical examination. In order to correct prevalence rates derived from self-reports, weight status categories based on self-reported and measured height and weight were used to estimate a correction formula according to an established procedure under consideration of body perception. The correction procedure was applied and corrected rates were estimated. Results The corrected prevalence of overweight, including obesity, derived from KiGGS Wave 1, showed that the rate has not further increased compared to the KiGGS baseline survey (18.9 % vs. 18.8 % based on the German reference). Conclusion The rates of overweight still remain at a high level. The results of KiGGS Wave 1 emphasise the significance of this health issue and the need for prevention of overweight and obesity in children and adolescents.

Objectives: Studies seeking direct estimates of the lung cancer risk associated with residential radon exposure lasting several decades have been conducted in many European countries. Individually these studies have not been large enough to assess moderate risks reliably. Therefore data from all 13 European studies of residential radon and lung cancer satisfying certain prespecified criteria have been brought together and analyzed. Methods: Data were available for 7148 persons with lung cancer and 14 208 controls, all with individual smoking histories and residential radon histories determined by long-term radon gas measurements. Results: The excess relative risk of lung cancer per 100 Bq/m3 increase in the observed radon concentration was 0.08 [95% confidence interval (95% CI) 0.03-0.16; P=0.0007] after control for confounding. The dose-response relationship was linear with no evidence of a threshold, and it remained significant when only persons with observed radon concentrations of

Studies on underground miners have shown an increased risk of lung cancer after exposure to high doses of radon and radon daughters. However, in the range of typical indoor radon exposures, there are still uncertainties on the strength of the association between radon exposure and the risk of lung cancer. Since 1990, population-based epidemiological studies have been performed in the USA, Canada, Sweden, Finland, Germany, Czech Republic, Austria, France, Italy, Spain, and China. Some of them did not find an effect, others have shown a statistically significant association of radon exposure and lung cancer risk. The reason for this heterogeneity is found in the different study designs, different ways of measuring radon, different ranges of radon concentrations, varying information on confounding factors, but most importantly limited sample size in most of the individual studies. Therefore, pooling studies are performed now in North America and Europe, which are close to be finished.

Tobacco smoking is one of the most frequently examined risk factors in epidemiological studies due to the high frequency of smoking in the population and its high risk potential. This paper discusses the issue of standardization of the assessment of tobacco exposure in German epidemiological studies based on a suggestion of the working group "Epidemiological methods" of the German Society of Epidemiology (DGEpi), the German Society of Social Medicine and Prevention (DGSMP), and German Society of Medical Informatics, Biometry and Epidemiology (GMDS) together with the working group "Epidemiology in the workplace" of the DGEpi and the German Society of Occupational and Environmental Medicine (DGAUM). The main element is a short questionnaire for German adults for the assessment of tobacco smoking in epidemiological studies where smoking is a potential confounder. In addition, information on the consideration of intermittent periods of non-smoking, a very short questionnaire for medical examinations in the workplace or non-responder interviews as well as the quantification and statistical modelling of smoking are presented. A brief discussion of scientific problems and questionnaires related to the exposure to environmental tobacco smoke is given.

Background A recent weakening and even decoupling of the association of body mass index (BMI) and systolic blood pressure (SBP) in population data was reported, i. a. for Western Europe. Methods The association of BMI and SBP in recent cross-sectional population data from Germany was investigated in participants aged 18–79 years with BMI 17.5-40 kg/m2 from national health examination surveys 1998 (n = 6,931) and 2008–2011 (n = 6,861) in Germany. The association was analyzed both in the overall samples and in participants without antihypertensive medication. Results From 1998 to 2008–11, age- and sex-standardized mean SBP decreased from 129.0 (CI 128.2-129.7) to 124.1 (123.5-124.6) mmHg in all participants and from 126.0 (125.4-126.7) to 122.3 (121.7-122.8) mmHg among persons not on antihypertensive medication. The proportion of persons treated with antihypertensives augmented from 19.2 % (17.7-20.8) to 25.3 % (24.0-26.6). Mean BMI remained constant at around 27 kg/m2 with a slight increase in obesity prevalence. BMI was positively associated with SBP both in 1998 and 2008–11, yet the association tended to level out with increasing BMI suggesting a non-linear association. The strength of the BMI-SBP-association decreased over time in all and untreated men. In women, the association weakened in the overall sample, but remained similarly strong in untreated women. The unadjusted linear regression models were used to estimate the increase in SBP within 5-unit BMI increases. E. g. for men in 1998, SBP was higher by 7.0 mmHg for a BMI increase from 20 to 25 kg/m2 and by 3.6 mmHg for BMI 30 to 35 kg/m2. The corresponding values for 2008–11 were 3.8 mmHg and 1.7 mmHg. Conclusions The cross-sectional association of BMI and SBP decreased between 1998 and 2008–11 in Germany, however it did not disappear and it is in part explained by improvements in the diagnosis and treatment of high blood pressure. Electronic supplementary material The online version of this article (doi:10.1186/s12889-015-2023-8) contains supplementary material, which is available to authorized users.

To evaluate risk factors for lung cancer in nonsmoking women, we used data of a case-control study conducted between 1991 and 1996 in Germany. A total of 234 female histologically confirmed lung cancer patients and 535 population controls who had never smoked more than 400 cigarettes in their lifetime were personally interviewed with respect to occupation, exposure to environmental tobacco smoke (ETS), family history of cancer, prior physician-diagnosed lung diseases or cancer and diet. One-year radon measurements in the last dwelling were performed. Odds ratios (OR) adjusted for age and region and 95% confidence intervals (CI) were calculated via logistic regression. When cumulative duration of exposure to ETS in hours was considered, the OR for high compared to not or low ETS exposed women was 2.62 (CI:1.35-5.06) for occupational exposure and OR=1.67 (CI:0.86-3.25) for spousal exposure, exhibiting a significant trend for ETS at work. Working more than 10 years in jobs or industries with known or suspected lung carcinogens was associated with OR=2.0 (CI:0.99-4.0). An elevated risk due to prior lung diseases was present for pneumonia (OR=1.6; CI:1.07-2.40) and tuberculosis (OR=1.6; CI:0.77-3.37). No significant increase in risk with increasing residential radon levels or with the presence of a family history of lung cancer was apparent. Protective effects were observed for high vs. low consumption of fresh vegetables (OR=0.5; CI:0.25-0.82) and cheese (OR=0.3, CI:0.21-0.55). ETS at work, occupational hazards and previous pneumonia may be risk factors for lung cancer in nonsmoking women, while a diet rich in fresh vegetables and cheese seems to be protective.

OBJECTIVE This study examined the association of HbA1c-defined glycemic status and continuous HbA1c with all-cause mortality. RESEARCH DESIGN AND METHODS The study population comprised 6,299 participants (aged 18–79 years) of the German National Health Interview and Examination Survey 1998, who were followed up for mortality for an average of 11.6 years. Glycemic status was defined as known diabetes (self-reported diagnosis or intake of antidiabetic medication) and based on HbA1c levels according to American Diabetes Association diagnostic criteria as undiagnosed diabetes (≥6.5% [≥48 mmol/mol]), prediabetes with very high (6.0–6.4% [42–46 mmol/mol]) or high diabetes risk (5.7–5.9% [39–41 mmol/mol]), and normoglycemia ( RESULTS Excess mortality risk was observed for participants with known diabetes (hazard ratio 1.41 [95% CI 1.08–1.84]) and undiagnosed diabetes (1.63 [1.23–2.17]) but not for those with high (1.02 [0.80–1.30]) or very high diabetes risk (0.87 [0.67–1.13]). Spline models revealed a U-shaped association, with lowest risk at HbA1c levels 5.4–5.6% (36–38 mmol/mol) and a significantly increased risk at ≤5.0% (≤31 mmol/mol) and ≥6.4% (≥46 mmol/mol). CONCLUSIONS Unlike known and undiagnosed diabetes, HbA1c levels in the prediabetic range were not associated with an increased mortality risk. The observed U-shaped relationship adds to existing evidence that not only high but also low HbA1c levels might be associated with all-cause mortality.

The "German Health Interview and Examination Survey for Children and Adolescents" (KiGGS) is part of the health monitoring system of the Robert Koch Institute (RKI). Following the KiGGS baseline study (2003 - 06), which comprised interviews and physical examinations of 0- to 17-year-old participants, KiGGS Wave 1 (2009 - 2012) was carried out as a telephone-based survey. In addition to providing longitudinal data, a second essential aim of KiGGS is to regularly provide population-based cross-sectional data on the health situation of children and adolescents aged 0-17 years living in Germany. Therefore, the study population of KiGGS Wave 1 consists of re-invited participants from the baseline study (KiGGS cohort), supplemented by newly invited children aged 0-6 years. The newly invited participants were randomly chosen from local population registries in the 167 baseline sample points. This method was chosen to supplement the sample with younger age groups. This article focuses on the age groups from 0 to 17 years, which are relevant for prevalence estimations among children and adolescents. In total 12,368 children and adolescents took part; among them 4,455 newly invited and 7,913 re-invited participants (response 38.8 and 72.9%, respectively). A comparison of the net sample with the resident German population (0-17 years) regarding particular population characteristics and an analysis of the relationship between the re-participation rate and certain characteristics collected in the baseline study (7-17 years) suggest a mostly unbiased sample. To account for certain aspects of the population and nonresponse, cross-sectional and trend analyses were partially corrected by weighting factors.

OBJECTIVE: Whether specific combinations of risk factors in very early life might allow identification of high-risk target groups for overweight prevention programs was examined. DESIGN AND METHODS: Data of n = 8981 children from the German KiGGS study were analyzed. Using a classification tree approach, predictive risk factor combinations were assessed for overweight in 3-6, 7-10, and 11-17-year-old children. RESULTS: In preschool children, the subgroup with the highest overweight risk were migrant children with at least one obese parent, with a prevalence of 36.6 (95% confidence interval or CI: 22.9, 50.4)%, compared to an overall prevalence of 10.0 (8.9, 11.2)%. The prevalence of overweight increased from 18.3 (16.8, 19.8)% to 57.9 (46.6, 69.3)% in 7-10-year-old children, if at least one parent was obese and the child had been born large-for-gestational-age. In 11-17-year-olds, the overweight risk increased from 20.1 (18.9, 21.3)% to 63.0 (46.4, 79.7)% in the highest risk group. However, high prevalence ratios were found only in small subgroups, containing

The "German Health Interview and Examination Survey for Adults" (DEGS) is part of the health monitoring program of the Robert Koch Institute (RKI) and is designed as a combined cross-sectional and longitudinal survey. The first wave (DEGS1; 2008-2011) comprised interviews and physical examinations. The target population were 18- to 79-year olds living in Germany. The mixed design consisted of a new sample randomly chosen from local population registries which was supplemented by participants from the "German National Health Interview and Examination Survey 1998" (GNHIES98). In total, 8,152 persons took part, among them 4,193 newly invited (response 42%) and 3,959 who had previously taken part in GNHIES98 (response 62%). 7,238 participants visited one of the 180 local study centres, 914 took part in the interview-only programme. The comparison of the net sample with the group of non-participants and with the resident population of Germany suggests a high representativeness regarding various attributes. To account for certain aspects of the population structure cross-sectional, trend and longitudinal analyses are corrected by weighting factors. Furthermore, different participation probabilities of the former participants of GNHIES98 are compensated for. An English full-text version of this article is available at SpringerLink as supplemental.

OBJECTIVE: Calculation of attributable risks (ARs) of childhood overweight to estimate effectiveness of prevention strategies. METHODS: We used pooled data of 4 population-based German studies including 34 240 children and adolescents aged 3 to 18 years to calculate the impact of familial, social, “early life”, and lifestyle factors on overweight. ARs (joint for all determinants as well as partial risks) were calculated. RESULTS: The prevalence of childhood overweight was 13.4%. Successfully tackling all determinants can reduce overweight by 77.7% (ie, from 13.4% to 3.0%; = joint AR) with partial effects of treating parental overweight (42.5%); improving social status (14.3%); reducing media time to CONCLUSIONS: The determinants identified explained 78% of the prevalence of overweight. Taking into account the partial ARs, the effectiveness of lifestyle interventions to prevent overweight in children is limited. Our data argue in favor of interventions aimed at families and social environments, with a major focus on promoting a lower screen time and computer use in children.

Background The German Health Interview and Examination Survey for Adults (DEGS) is part of the recently established national health monitoring conducted by the Robert Koch Institute. DEGS combines a nationally representative periodic health survey and a longitudinal study based on follow-up of survey participants. Funding is provided by the German Ministry of Health and supplemented for specific research topics from other sources. Methods/design The first DEGS wave of data collection (DEGS1) extended from November 2008 to December 2011. Overall, 8152 men and women participated. Of these, 3959 persons already participated in the German National Health Interview and Examination Survey 1998 (GNHIES98) at which time they were 18–79 years of age. Another 4193 persons 18–79 years of age were recruited for DEGS1 in 2008–2011 based on two-stage stratified random sampling from local population registries. Health data and context variables were collected using standardized computer assisted personal interviews, self-administered questionnaires, and standardized measurements and tests. In order to keep survey results representative for the population aged 18–79 years, results will be weighted by survey-specific weighting factors considering sampling and drop-out probabilities as well as deviations between the design-weighted net sample and German population statistics 2010. Discussion DEGS aims to establish a nationally representative data base on health of adults in Germany. This health data platform will be used for continuous health reporting and health care research. The results will help to support health policy planning and evaluation. Repeated cross-sectional surveys will permit analyses of time trends in morbidity, functional capacity levels, disability, and health risks and resources. Follow-up of study participants will provide the opportunity to study trajectories of health and disability. A special focus lies on chronic diseases including asthma, allergies, cardiovascular conditions, diabetes mellitus, and musculoskeletal diseases. Other core topics include vaccine-preventable diseases and immunization status, nutritional deficiencies, health in older age, and the association between health-related behavior and mental health.

Objective: We analyzed the magnitude of the association between cardiovascular disease (CVD) risk factors and various measures of overweight among adolescents, to determine which indicator of overweight is most relevant for risk assessment. Methods: 5,546 boys and girls aged 11–17 years participating in the German Health Interview and Examination Survey for Children and Adolescents (KiGGS) were studied. Overweight was assumed when different anthropometric variables exceeded age- and sex-specific 90th percentiles. Blood pressure was measured and blood samples were analyzed for serum total cholesterol, lipoproteins, high-sensitivity C-reactive protein, and glycosylated hemoglobin (HbA1c). Results: In both sexes, overweight was significantly associated with adverse levels of CVD risk factors, except HbA1c. These associations were most pronounced for overweight as defined by waist circumference (WC), waist-to-height ratio (WHtR), or BMI. Between 11% and 37% of the overweight children exceeded the defined cut-offs for individual CVD risk factors, with age- and puberty-adjusted significant odds ratios (95% confidence interval (CI)) in comparison to normal-weight age mates ranging from 1.7 (1.0–3.0) to 6.1 (4.5–8.2). Conclusions: The findings of this population-based survey suggest that, among adolescents, WC, WHtR, and BMI are easily applicable measures of overweight that appear to be relevant for CVD risk assessment.

Background For practical and financial reasons, self-reported instead of measured height and weight are often used. The aim of this study is to evaluate the validity of self-reports and to identify potential predictors of the validity of body mass index (BMI) derived from self-reported height and weight. Findings Self-reported and measured data were collected from a sub-sample (3,468 adolescents aged 11-17) from the German Health Interview and Examination Survey for Children and Adolescents (KiGGS). BMI was calculated from both reported and measured values, and these were compared in descriptive analyses. Linear regression models with BMI difference (self-reported minus measured) and logistic regression models with weight status misclassifications as dependent variables were calculated. Height was overestimated by 14- to 17-year-olds. Overall, boys and girls under-reported their weight. On average, BMI values calculated from self-reports were lower than those calculated from measured values. This underestimation of BMI led to a bias in the prevalence rates of under- and overweight which was stronger in girls than in boys. Based on self-reports, the prevalence was 9.7% for underweight and 15.1% for overweight. However, according to measured data the corresponding rates were 7.5% and 17.7%, respectively. Linear regression for BMI difference showed significant differences according to measured weight status: BMI was overestimated by underweight adolescents and underestimated by overweight adolescents. When weight status was excluded from the model, body perception was statistically significant: Adolescents who regarded themselves as 'too fat' underestimated their BMI to a greater extent. Symptoms of a potential eating disorder, sexual maturation, socio-economic status (SES), school type, migration background and parental overweight showed no association with the BMI difference, but parental overweight was a consistent predictor of the misclassification of weight status defined by self-reports. Conclusions The present findings demonstrate that the observed discrepancy between self-reported and measured height and weight leads to inaccurate estimates of the prevalence of under- and overweight when based on self-reports. The collection of body perception data and parents' height and weight is therefore recommended in addition to self-reports. Use of a correction formula seems reasonable in order to correct for differences between self-reported and measured data.

While the association of gestational diabetes mellitus and abnormal glucose tolerance is beyond doubt, its associations with other cardiovascular disease risk factors in the offspring are less clearly established. Some of these associations, in particular overweight in the offspring, might be confounded by maternal overweight.Data on 12,542 children in the age of 3-17 years with full information about gestational diabetes mellitus and maternal BMI were available from the German nationwide KiGGS study. We calculated linear and logistic regression models for measurements of body composition, blood pressure, HbA(1c) and cholesterol values in the offspring with gestational diabetes mellitus as the explanatory variable, with and without adjustment for maternal BMI.The prevalence of gestational diabetes mellitus in the dataset was 2.2%. Unadjusted regression analyses suggested weak positive effects of gestational diabetes mellitus on body composition measurements [e.g. a mean increase in BMI standard deviation scores (SDS) of 0.17 units (95% confidence interval: 0.03, 0.30)]. After adjustment for maternal BMI, the observed associations almost disappeared [e.g. BMI SDS: 0.07 (-0.06, 0.20)]. With respect to blood pressure and cholesterol, no potential effects of gestational diabetes mellitus were observed in both unadjusted and adjusted models.Gestational diabetes mellitus does not appear to have a relevant effect on cardiovascular disease correlates such as blood pressure or cholesterol levels in children, and the potential effect of gestational diabetes mellitus on body composition seems to be widely explainable by maternal BMI.

OBJECTIVES: To present oscillometric blood pressure (BP) references from German nonoverweight children and compare them with US references. METHODS: From children and adolescents, aged 3 to 17 years, from the German Health Interview and Examination Survey for Children and Adolescents (KiGGS 2003–2006), we obtained standardized BP measurements by using an oscillometric device validated in children. Gender-specific systolic (SBP) and diastolic (DBP) BP percentiles, which simultaneously accounted for age and height by use of advanced statistical methods, were derived from nonoverweight children to avoid overweight prevalence in the reference population influencing BP references. RESULTS: The age- and gender-specific 95th percentiles from nonoverweight children (n = 12 199) were lower by up to 3 mm Hg for SBP and up to 2 mm Hg for DBP compared with the total sample (N = 14 349). KiGGS percentiles from nonoverweight children accounting simultaneously for age and height were mostly lower than in the US reference sample but higher for SBP in boys aged 14 years or older. At median height, the age-specific differences in 95th percentiles of SBP ranged from −4 to 4 mm Hg in boys and −2 to 1 mm Hg in girls and, for DBP, from −6 to 2 mm Hg in boys and −5 to 2 mm Hg in girls. CONCLUSIONS: Compared with current US references, the proposed German BP reference values are not influenced by the prevalence of overweight children in the reference population, they are based on a validated oscillometric device, and they take advantage of improved statistical methods.

To present valid head circumference (HC) percentiles from early infancy to 18 years and to compare them with percentiles currently used in Germany by Prader, as well as to international WHO and CDC references.Nationally representative sample of 17,158 children and adolescents aged 0.25-17.98 years (KiGGS study 2003-2006) with standardized HC measurement. HC references were created using Cole's LMS method.The median growth of HC is largest in the first year of life. Adult HC is reached at age 16 years in girls, while in boys, HC growth continues through age 17 years and adult HC have to be derived from future KiGGS follow-up examinations. KiGGS percentiles are quite similar from early infancy to early school age compared to older Prader references, but higher thereafter (maximum difference of median HC: girls 1.4 cm, boys 0.9 cm). KiGGS percentiles are also higher than WHO and CDC percentiles over most of the compared age range, but differences are less pronounced compared to Prader.The KiGGS HC references presented here for boys and girls aged 4 months through 17 years are more valid than currently used German references. Because of the similarity of KiGGS and the currently used reference by Prader in early infancy, the currently used Prader reference for 0-4 months could complement KiGGS to cover the entire age range from birth to the end of adolescence.

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 90th percentile of BMI z-score and of 0.20 [0.07, 0.33] units at the 97th 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.

The aim of this study was to develop age- and sex-specific percentile curves for waist circumference (WC) in German adolescents.A cross-sectional population-based study (German Health Interview and Examination Survey for Children and Adolescents [KiGGS]) was carried out in a large nationally representative sample of 3 345 males and 3 221 females aged 11.0 to 18.0 years from May 2003 to May 2006. Smoothed percentile curves of WC were derived by the LMS method.Girls had lower WC values than boys at any age and percentile. WC increased with age in both boys and girls. The curves show a fairly linear pattern for males, but for females they begin to level off after the age of 13 years.The presented WC percentile curves are based on a representative sample of adolescents living in Germany and standardized measurements. We propose their use for clinical practice to monitor abdominal obesity in adolescents, although there is a need for future studies correlating cut-offs with health outcomes. The German curves could contribute to the feasibility of combining representative data from several countries to establish an international reference for WC.

Objectives: The objective of the present study is to present height-for-age percentiles representative for infants, children and adolescents in Germany and to compare them with existing German height references by Kromeyer-Hauschild (KH) and with international growth charts from the Centers for Disease Control (CDC) as well as the growth standard and the growth reference of the World Health Organization (WHO). Methods: The reference population consists of a nationally representative sample of 17 079 children and adolescents aged 0–17 years (KiGGS study 2003–2006) with standardized height measurements. Height reference curves were created using Cole's LMS method. To compare KiGGS with other reference systems, KiGGS height values were transformed to SD-scores using the KH, WHO and CDC references. Results: Height-for-age percentiles in KiGGS increase until age 16 years in girls and until the end of the observed age range (17.98 years) for boys. The difference in height between boys and girls is negligible before puberty and reaches 13cm at age 17.98 years. KiGGS and KH percentiles overlap almost completely with only slight differences. However, there are substantial differences in SD-score levels between KiGGS and international data. Especially in the extreme percentiles, KiGGS percentiles are generally positioned above WHO and CDC. For example, the KiGGS 3rd height percentile corresponds to the 8th percentile according to CDC and WHO (5–18 years) and to the 6th percentile in the 0- to 5-year-olds in the WHO growth standard and the KiGGS 97th height percentile in boys and girls corresponds to the 99th percentile in CDC and WHO. Conclusions: The KiGGS height-for-age reference can be recommended as a national height reference for screening and monitoring growth in infants (starting from 4 months of age), children and adolescents in Germany. In German samples, the WHO and CDC references can be used for international comparisons.

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.

A number of cross-sectional and prospective studies suggested a priming effect of maternal smoking in pregnancy on offspring’s obesity. It has been hypothesized that this association might be explained by low birth weight and subsequent catch-up growth in the causal pathway. We therefore examined the role of birth weight in children exposed versus not exposed to cigarette smoking in utero on later body mass index (BMI). Using data of 12,383 children and adolescents (3–17 years of age) recorded in a German population-based survey (KiGGS), we assessed mean body mass index standard deviation scores (BMI-SDS) in different birth weight SDS categories, stratified for children with smoking and non-smoking mothers. We calculated spline regression models with BMI-SDS as outcome variable, cubic splines of birth weight SDS, and potential confounding factors. Children whose mothers had been smoking during pregnancy had lower birth weight SDS and higher BMI-SDS at interview compared to children of non-smoking mothers. However, we observed a linear association between birth weight SDS and BMI-SDS in crude analyses for both groups. Similarly, almost linear effects were observed in adjusted spline regression analyses, except for children with very low birth weight. The respective 95% confidence bands did not preclude a linear effect for the whole birth weight SDS distribution. Our findings suggest that low birth weight is unlikely to be the main cause for the association between intrauterine nicotine exposure and higher BMI in later life. Alternative mechanisms, such as alterations in the noradrenergic system or increased food efficiency, have to be considered.

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).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.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.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.

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.

Studies on miners as well as epidemiological studies in the general population show an increased lung cancer risk after exposure to radon and its progeny. The European pooled analysis of indoor radon studies estimates an excess relative risk of 8% (16% after correction for measurement uncertainties) per 100 Bq m(-3) indoor radon concentration. Here, we determine the population attributable fraction (PAF) for lung cancer due to residential radon based on this risk estimate for Switzerland and Germany. Based on regionally stratified radon data, the PAF was calculated following the World Health Organization concept of global burden of disease, compared to a realistic baseline radon concentration equal to the outdoor concentration. Lifetable approaches were used taking smoking and sex into account. Measurement error corrections were applied to both risk estimates and the radon distribution. In Switzerland, the average indoor radon concentration is 78 Bq m(-3), resulting in a PAF of 8.3%. Therefore, 169 male lung cancer deaths and 62 deaths in women can be attributed to residential radon per year. For Germany, the average indoor radon concentration is 49 Bq m(-3), corresponding to a PAF of 5.0% (1,422 male and 474 female deaths annually). In both countries, a large regional variation in the PAF was observed due to regional differences in radon concentrations and population structure. Both calculations show a strong dependency on the risk model used. Risk models based on miner studies result in higher PAF estimates than risk models based on indoor radon studies due to different assumptions regarding exposures received more than 35 years ago. The use of a non-zero baseline radon concentration also contributes to the lower PAF estimates reported here. Although the estimates of the population attributable fraction of residential radon presented here are lower than previously reported estimates, the risk is still one of the most widespread environmental hazards. Radon monitoring and radon reduction programs are therefore important issues for environmental public health management.

Background From May 2003 to May 2006, the Robert Koch Institute conducted the German Health Interview and Examination Survey for Children and Adolescents (KiGGS). Aim of this first nationwide interview and examination survey was to collect comprehensive data on the health status of children and adolescents aged 0 to 17 years. Methods/Design Participants were enrolled in two steps: first, 167 study locations (sample points) were chosen; second, subjects were randomly selected from the official registers of local residents. The survey involved questionnaires filled in by parents and parallel questionnaires for children aged 11 years and older, physical examinations and tests, and a computer assisted personal interview performed by study physicians. A wide range of blood and urine testing was carried out at central laboratories. A total of 17 641 children and adolescents were surveyed – 8985 boys and 8656 girls. The proportion of sample neutral drop-outs was 5.3%. The response rate was 66.6%. Discussion The response rate showed little variation between age groups and sexes, but marked variation between resident aliens and Germans, between inhabitants of cities with a population of 100 000 or more and sample points with fewer inhabitants, as well as between the old West German states and the former East German states. By analysing the short non-responder questionnaires it was proven that the collected data give comprehensive and nationally representative evidence on the health status of children and adolescents aged 0 to 17 years.

Background: A recent analysis indicates that the excess odds ratio for lung cancer by smoking is described by a function that is linear in pack-years and exponential in the logarithm of smoking intensity and its square (Cancer Epidemiol Biomarkers Prev. 2006;15:517–523). The model suggests that below 15–20 cigarettes per day there is a “direct exposure rate” effect, ie, the excess odds ratio per pack-year for higher intensity (and shorter duration) smokers is greater than for lower-intensity (and longer duration) smokers. Above 20 cigarettes per day, there is an “inverse-exposure-rate” effect, ie, the excess odds ratio per pack-year for higher intensity smokers is smaller than for lower-intensity smokers. Methods: Using pooled data from 2 large case-control studies of lung cancer (the European Smoking and Health Study and the German Radon Study), we evaluated effect modification of the association between smoking and lung cancer. Results: Interaction effects are very specific. Variations in risk of lung cancer with years since cessation of smoking, age, method of inhalation, and type of cigarette result from interactions with smoking intensity, and not total pack-years. In contrast, risk variations by sex result from the interaction with total pack-years, while intensity effects are homogeneous. Risk variations by age at which smoking started result from interactions with both total pack-years and intensity. All intensity interactions are homogeneous across studies. Conclusions: The specificity of the interactions may provide clues for the molecular basis of the smoking and lung cancer relationship.

A recent analysis showed that the excess odds ratio (EOR) for lung cancer due to smoking can be modeled by a function which is linear in total pack-years and exponential in the logarithm of smoking intensity and its square. Below 15-20 cigarettes per day, the EOR/pack-year increased with intensity (direct exposure rate or enhanced potency effect), suggesting greater risk for a total exposure delivered at higher intensity (for a shorter duration) than for an equivalent exposure delivered at lower intensity. Above 20 cigarettes per day, the EOR/pack-year decreased with increasing intensity (inverse exposure rate or reduced potency effect), suggesting greater risk for a total exposure delivered at lower intensity (for a longer duration) than for an equivalent exposure delivered at higher intensity. The authors applied this model to data from 10 case-control studies of cancer, including cancers of the lung, bladder, oral cavity, pancreas, and esophagus. At lower intensities, there was enhanced potency for several cancer sites, but narrow ranges for pack-years increased uncertainty, precluding definitive conclusions. At higher intensities, there was a consistent reduced potency effect across studies. The intensity effects were statistically homogeneous, indicating that after accounting for risk from total pack-years, intensity patterns were comparable across the diverse cancer sites.