Katrin Kromeyer-Hauschild

Perzentile für den Body-mass-Index für das Kindes- und Jugendalter unter Heranziehung verschiedener deutscher Stichproben

ZusammenfassungFragestellung. Sowohl die Childhood Group der International Obesity Task Force (IOTF) als auch die European Childhood Obesity Group (ECOG) empfehlen den Body-mass-Index als Beurteilungskriterium für Übergewicht und Adipositas bei Kindern und Jugendlichen. Im Erwachsenenalter erfolgt die Definition von Übergewicht und Adipositas anhand fester Grenzwerte, bei der Beurteilung von Kindern und Jugendlichen müssen die alters- und geschlechtsspezifischen Veränderungen des BMI berücksichtigt werden. Methode. Unter Heranziehung von 17 bereits durchgeführten Untersuchungen aus verschiedenen Regionen Deutschlands wurden BMI-Perzentile für Kinder und Jugendliche erstellt. Die Berechnung der Perzentile basiert auf den Körperhöhen- und Körpergewichtsdaten von 17.147 Jungen und 17.275 Mädchen im Alter von 0–18 Jahren. Ergebnisse und Schlussfolgerung. Die vorgestellten Perzentile sollten als Referenz für deutsche Kinder und Jugendliche angewendet werden. Die Arbeitsgemeinschaft “Adipositas im Kindes- und Jugendalter” (AGA) hat in ihren Leitlinien die Anwendung der hier vorgestellten 90. und 97. Perzentile zur Definition von Übergewicht und Adipositas empfohlen.AbstractObjectives. Both the Childhood Group of the International Obesity Task Force (IOTF) and the European Childhood Obesity Group (ECOG) recommend to use the body mass index (BMI = weight in kilograms/height in meter2) to evaluate overweight and obesity in children and adolescents. Whereas it is customary with adults to use fixed cut off points to define overweight and obesity, in children and adolescents age and sex specific developmental changes in BMI need to be addressed, which are due to physiological alterations of fat mass. Method. Because a national reference population for children and adolescents does not exist in Germany, a BMI reference data set was compiled. Therefore measurements of height and weight from 17 different regional studies including 17147 boys and 17275 girls aged 0 to 18 years were used. Results and conclusions. We recommend the use of the presented percentiles as reference to asses under- and overweight (obesity) in German children and adolescents. In the guidelines of the “Arbeitsgruppe Adipo-sitas im Kindes- und Jugendalter” (AGA) the 90th and 97th BMI percentiles as calculated in this reference population are proposed as cut-off points for the definition of overweight and obesity in German children and adolescents.

Secular trends in body mass index in German children and adolescents: a cross-sectional data analysis via CrescNet between 1999 and 2006

To assess secular trends in alterations in body mass index (BMI) in German children and adolescents between 1999 and 2006, we performed an analysis using data from a computerized database (CrescNet) and focusing on the data ranges above the 97th percentile (P97) and below the median (P50). This cross-sectional assessment of BMI data used a total of 143 495 single values (73 290 males and 70 205 females aged 0.5-17.5 years) from screening and/or consulting visits at 1 of the 294 participating German pediatricians. Body mass index data were calculated from standardized measurements of body weight and height entered into the CrescNet database. Individual percentiles were estimated according to German reference data sets. Across all age groups, the respective mean value of children with BMI above P97 increased from 5.32% to 7.02% in boys and from 5.70% to 7.18% in girls between 1999 and 2006, whereas those below P50 decreased from 48.52% to 43.71% in boys and from 47.48% to 42.57% in girls. The proportions of obese children (above the 97th percentile) were significantly higher than estimated by German reference values throughout the study period. The significant increase in childhood obesity between 1999 and 2006 was more pronounced in boys compared to girls. In conclusion, the cross-sectional study performed at a large cohort of German children and adolescents reveals an alarming increase in the number of obese children and adolescents and an accompanied shift toward higher BMI values. As the number of children below the 50th centile decreases accordingly, the shift in the distribution panel of the German reference percentile curves affecting the whole population can be observed.

Nationally representative waist circumference percentiles in German adolescents aged 11.0–18.0 years

OBJECTIVE The aim of this study was to develop age- and sex-specific percentile curves for waist circumference (WC) in German adolescents. METHODS 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. RESULTS 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. CONCLUSIONS 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.

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

Objective: The aim of this study was to compare the fixed 0.5 cut-off and the age- and sex-specific 90th percentile (P90) for waist-to-height ratio (WHtR) in German adolescents with respect to the prevalence of abdominal obesity and to compare the screening ability of WHtR and BMI to identify hypertensive blood pressure (BP) values. Methods: Between 2003 and 2006, the German Health Interview and Examination Survey for Children and Adolescents (KiGGS) was carried out including 3,492 boys and 3,321 girls aged 11-17 years. Abdominal obesity was assessed by two WHtR cut-points (P90; 0.5). Hypertensive BP was defined as BP exceeding age-, sex- and height-specific 95th percentiles or the adult threshold for hypertension (140/90 mm Hg). Results: Agreement between the WHtR cut-offs was very good (Kappa 0.89 for boys; 0.81 for girls), and the prevalence of abdominal obesity was slightly higher using P90 (boys 12.0%; girls 11.3%) compared to 0.5 (boys 10.7%; girls 8.0%). WHtR and BMI-for-age had equivalent ability to discriminate hypertensive BP (ROC-AUC < 0.7; sensitivity of the 0.5 cut-off for detecting hypertensive BP < 30%). Conclusion: The fixed 0.5 WHtR cut-off can be used in German adolescents to characterize abdominal obesity. However, WHtR is not suitable as a screening tool for hypertensive BP in adolescents.

Zunahme der Häufigkeit von Übergewicht und Adipositas bei Jenaer Kindern

ZusammenfassungFragestellung/Hintergrund: Es wurden Veränderungen des Body-mass-Index (BMI) bei Kindern in den letzten 20 Jahren untersucht und die Prävalenz von Übergewicht und Adipositas bestimmt. Methode und Probanden: Körperhöhe und Körpergewicht wurden im Rahmen anthropologischer Querschnittsuntersuchungen in den Jahren 1975, 1985 und 1995 bei 7- bis 14jährigen Jenaer Kindern erfaßt und daraus der Body-mass-Index berechnet. Die Einstufung der untersuchten Kinder als übergewichtig und adipös erfolgte anhand der von der European Childhood Obesity Group empfohlenen alters- und geschlechtsspezifischen 90. oder 97. Perzentile für den BMI von Rolland-Cachera et al. [31]. Ergebnisse: Zwischen 1975 und 1995 stieg der BMI der Jenaer Kinder an. Der prozentuale Anteil von Kindern, die als übergewichtig oder adipös einzustufen sind, nahm ebenfalls zu. Diese Veränderungen fielen zwischen 1985 und 1995 besonders deutlich aus. Schlußfolgerungen: Veränderte Lebensbedingungen, wie z. B. Änderungen beim Freizeitverhalten, beim Ernährungsverhalten oder in der Familienstruktur, die im Zusammenhang mit der politischen Wende im Jahr 1989 auftraten, werden als Ursache für diesen Trend angesehen.SummaryObjective: To examine changes in Body Mass Index (BMI) in children in the last twenty years and to determine the prevalence of overweight and obesity. Design and Subjects: Body height and body weight were measured in Jena school children 7 to 14 years of age in cross-sectional anthropological investigations in 1975, 1985 and 1995 and from these measurements the Body Mass Index (BMI) was calculated. The investigated children were classified as overweight or obese by the age- and sex-specific 90th or 97th percentile values of BMI from Rolland-Cachera et al. [31] recommended by the European Childhood Obesity Group. Results: Between 1975 and 1995 the BMI of Jena children increased. The prevalence of overweight and obesity among the children increased also. These changes were striking between 1985 and 1995. Conclusions: Changing living conditions, e. g. changes in the leisure-time lifestyle, in dietary practices and in the families, related to the unification of Germany in 1989, may be caused this trend.

Growth studies in Jena, Germany: Changes in body size and subcutaneous fat distribution between 1975 and 1995

This report presents results of an anthropological investigation on Jena, Germany, schoolchildren from 1995. Stature and weight, body mass index (BMI), and four skinfolds (biceps, triceps, subscapular, suprailiac) are presented for children 7–14 years of age and are compared with results of investigations on schoolchildren carried out in Jena in 1975 and 1985. Between those years, in both sexes there were no significant differences in stature, weight, and consequently in the BMI. In this timespan, a trend toward a reduction of subcutaneous fat was noted. A different development was observed in the period 1985–1995. Stature as well as body weight increased, and because the increase in weight was greater than expected from the increase in stature, there also was an increase in the BMI. A large increase in overall subcutaneous fatness was also found. In 1995, the highest amount of body fat was observed in Jena children since 1975. Changes in the distribution of subcutaneous fat tissue occurred. Between 1975 and 1985, the ratio of trunk to extremity skinfolds (T/E ratio) decreased significantly in boys and girls in all ages, but increased between 1985 and 1995. In spite of this increase, children had the largest T/E ratio in 1975. Changes in the nutritional situation and other factors in living conditions, possibly related to the unification of Germany in 1989 influencing somatic development, are considered. Am. J. Hum. Biol. 10:579–587, 1998.

Body Fat Percentiles for German Children and Adolescents

Objective: The aim of this study was to define body fat percentiles for German children and adolescents aged 3–16 years using the largest German database. Methods: The study population included 11,632 girls and 11,604 boys. Data were pooled from: i) Kiel Obesity Prevention Study (KOPS), acquisition period: 1996–2008, n = 12,237; ii) ‘Better diet. More exercise. KINDERLEICHT-REGIONS’, acquisition period: 2007, n = 9,405; and iii) examination of Jena schoolchildren, acquisition period: 2005, n = 1,594. Body fat mass was measured by bioelectrical impedance analysis using a population-specific algorithm. Data were weighted to achieve a representative sample for Germany. Percentile curves were constructed by the LMS method and proved by Worm plots and Q-statistic. Results: In both genders, the higher body fat percentile curves sloped downwards to age 7 years, whereas the lower percentiles declined up to 8.5 years. Thereafter fat mass remained nearly constant with age in boys and increased in girls. The 10th percentile achieved a minimum of 10–11% body fat in both genders, whereas the 90th percentile curve fluctuated between 29 and 44% in boys or 30–43% in girls. The association between fat mass and blood pressure was too weak to define disease-related cut-offs. Conclusion: These body fat percentiles are suitable reference values for German children and adolescents.

KRAS status and epidermal growth factor receptor expression as determinants for anti-EGFR therapies in salivary gland carcinomas

Salivary gland carcinomas (SGC) are rare cancers with poor prognosis and limited response to conventional chemotherapy. New strategies based on molecular targeted therapy are needed and the EGFR signaling cascade is considered a possible key pathway for therapeutic molecules. We have analyzed 65 SGC of the main histopathological types for the expression of EGFR and and the mutation status of its downstream effector KRAS. EGFR overexpression (+2, +3) has been identified by immunohistochemistry in 75.4%. KRAS mutation analysis was performed by direct genomic sequencing and revealed a KRAS wildtype in 98.5% except of one adenoid cystic carcinoma with a GGT-GAT transition at codon 12 (Gly12Asp). EGFR overexpression and KRAS wildtype are prerequisites for a successful anti-EGFR therapy. The results of this study plead in favor of further therapeutic trials with EGFR-targeting monoclonal antibodies in SGC.

Growth studies in Jena, Germany: Changes in sitting height, biacromial and bicristal breadth in the past decenniums.

Changes in sitting height, biacromial and bicristal breadths, and the acromio‐cristal index in school children from Jena between 7 and 14 years of age are described. Additionally, a secular comparison of these measurements and the index was done, based on the long series of surveys available for schoolchildren in Jena. During childhood, sex differences in the dimensions and the index are usually slight, but with the onset of the adolescent spurt sex differences are clear. Females become relatively broader‐hipped and shorter‐legged than males, with the differences especially marked in the acromio‐cristal index. Biacromial and bicristal breadths and sitting height increased, on average, between the first investigation in 1975 and the survey in 1995. In contrast, the acromio‐cristal index remained almost constant in boys and girls over the observed time, with few exceptions. When related to stature, both breadth measurements of the trunk have increased, whereas the ratio of sitting height to stature remained constant in most age groups between 1975 and 1995. Am. J. Hum. Biol. 12:646–654, 2000.

No Incidence of BRAF Mutations in Salivary Gland Carcinomas—Implications for Anti-EGFR Therapies

BRAF is the main effector of KRAS in the RAS-RAF-MAPK axis, a signaling pathway downstream of EGFR. The activation of this cascade is an important pathway in cancer development and is considered a key pathway for therapeutic molecules. Recent studies in metastatic colorectal cancer found that an oncogenic activation of BRAF by a point mutation in exon 15 (V600E) could bypass the EGFR-initiated signaling cascade with the effect that patients bearing the mutant BRAF allele are not likely to benefit from EGFR-targeted therapies. We designed an allele-specific PCR and screened 65 salivary gland carcinoma (SGC) of the main histopathological types for the BRAF V600E mutation. All 65 SGC in this cohort (100%) presented the BRAF wildtype. In a previous study, we found a KRAS wildtype in 98.5% of SGC. These findings imply that SGC rarely acquires mutations that result in a constitutive activation of the signaling cascade downstream of EGFR and this pleads in favor of further therapeutic trials with EGFR-targeting monoclonal antibodies.