TY - JOUR A1 - Mumm, Rebekka A1 - Scheffler, Christiane A1 - Hermanussen, Michael T1 - Locally structured correlation (LSC) plots describe inhomogeneity in normally distributed correlated bivariate variables JF - Archives of Public Health N2 - Background The association between bivariate variables may not necessarily be homogeneous throughout the whole range of the variables. We present a new technique to describe inhomogeneity in the association of bivariate variables. Methods We consider the correlation of two normally distributed random variables. The 45° diagonal through the origin of coordinates represents the line on which all points would lie if the two variables completely agreed. If the two variables do not completely agree, the points will scatter on both sides of the diagonal and form a cloud. In case of a high association between the variables, the band width of this cloud will be narrow, in case of a low association, the band width will be wide. The band width directly relates to the magnitude of the correlation coefficient. We then determine the Euclidean distances between the diagonal and each point of the bivariate correlation, and rotate the coordinate system clockwise by 45°. The standard deviation of all Euclidean distances, named “global standard deviation”, reflects the band width of all points along the former diagonal. Calculating moving averages of the standard deviation along the former diagonal results in “locally structured standard deviations” and reflect patterns of “locally structured correlations (LSC)”. LSC highlight inhomogeneity of bivariate correlations. We exemplify this technique by analyzing the association between body mass index (BMI) and hip circumference (HC) in 6313 healthy East German adults aged 18 to 70 years. Results The correlation between BMI and HC in healthy adults is not homogeneous. LSC is able to identify regions where the predictive power of the bivariate correlation between BMI and HC increases or decreases, and highlights in our example that slim people have a higher association between BMI and HC than obese people. Conclusion Locally structured correlations (LSC) identify regions of higher or lower than average correlation between two normally distributed variables. KW - Standard deviation KW - Locally structured standard deviation KW - Locally structured correlation KW - Variance Y1 - 2022 U6 - https://doi.org/10.1186/s13690-021-00748-4 SN - 0778-7367 SN - 2049-3258 VL - 80 PB - Springer Nature BMC CY - Bruxelles ER - TY - JOUR A1 - Mumm, Rebekka A1 - Scheffler, Christiane A1 - Hermanussen, Michael T1 - Locally structured correlation (LSC) plots describe inhomogeneity in normally distributed correlated bivariate variables JF - Archives of public health = Archives belges de santé publique = Belgisch archief voor volksgezondheid N2 - Background The association between bivariate variables may not necessarily be homogeneous throughout the whole range of the variables. We present a new technique to describe inhomogeneity in the association of bivariate variables. Methods We consider the correlation of two normally distributed random variables. The 45 degrees diagonal through the origin of coordinates represents the line on which all points would lie if the two variables completely agreed. If the two variables do not completely agree, the points will scatter on both sides of the diagonal and form a cloud. In case of a high association between the variables, the band width of this cloud will be narrow, in case of a low association, the band width will be wide. The band width directly relates to the magnitude of the correlation coefficient. We then determine the Euclidean distances between the diagonal and each point of the bivariate correlation, and rotate the coordinate system clockwise by 45 degrees. The standard deviation of all Euclidean distances, named "global standard deviation", reflects the band width of all points along the former diagonal. Calculating moving averages of the standard deviation along the former diagonal results in "locally structured standard deviations" and reflect patterns of "locally structured correlations (LSC)". LSC highlight inhomogeneity of bivariate correlations. We exemplify this technique by analyzing the association between body mass index (BMI) and hip circumference (HC) in 6313 healthy East German adults aged 18 to 70 years. Results The correlation between BMI and HC in healthy adults is not homogeneous. LSC is able to identify regions where the predictive power of the bivariate correlation between BMI and HC increases or decreases, and highlights in our example that slim people have a higher association between BMI and HC than obese people. Conclusion Locally structured correlations (LSC) identify regions of higher or lower than average correlation between two normally distributed variables. KW - Standard deviation KW - Locally structured standard deviation KW - Locally KW - structured correlation KW - Variance Y1 - 2022 U6 - https://doi.org/10.1186/s13690-021-00748-4 SN - 0778-7367 SN - 2049-3258 VL - 80 IS - 1 PB - BMC CY - London ER - TY - JOUR A1 - Azcorra, Hugo A1 - Dickinson, Federico A1 - Mendez-Dominguez, Nina A1 - Mumm, Rebekka A1 - Valentín, Graciela T1 - Development of birthweight and length for gestational age and sex references in Yucatan, Mexico JF - American journal of human biology : the official journal of the Human Biology Council N2 - Objective To develop sex- and gestational age specific reference percentiles and curves for birth weight and length for Yucatec neonates using data from birth registers of infants born during 2015-2019. Material and methods Observational, descriptive, epidemiologic study in a 5-year period including every registered birth in the state of Yucatan, Mexico using birth registries. A total of 158 432 live, physically healthy singletons (76 442 females and 81 990 males) between 25 and 42 weeks of gestation were included in the analysis. We used the LMS method to construct smoothed reference centiles (3rd, 10th, 25th, 50th, 75th, 95th, and 97th) and curves for males and females separately. Results Mean maternal age was 26 (SD = 6.22) years. Fifty-two percent of births occurred by vaginal delivery, 37% were firstborn and similar proportions were second (33%) and third or more (30%) born. 5.5% of newborns included in the references corresponds to neonates born before 37 weeks of gestation (5.9% boys and 5.1% girls). In both sexes, the percentage of infants with a birthweight less than 2500 g was 6.7%. The birthweight at the 50th percentile for males and females at 40 weeks of gestation in this cohort was 3256 and 3167 g, respectively, and the corresponding values for birth length were 50.23 and 49.84 cm (mean differences between sexes: 89 g and 0.40 cm, respectively). Conclusion The reference percentile and curves developed in this study are useful for research purposes and can help health practitioners to assess the biological status of infants born in Yucatan. Y1 - 2022 U6 - https://doi.org/10.1002/ajhb.23732 SN - 1042-0533 SN - 1520-6300 VL - 34 IS - 6 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Mumm, Rebekka A1 - Hermanussen, Michael T1 - The dilemma of misclassifying weight in short and in historic population JF - Human biology and public health N2 - Background: Clinicians often refer anthropometric measures of a child to so-called “growth standards” and “growth references. Over 140 countries have meanwhile adopted WHO growth standards. Objectives: The present study was conducted to thoroughly examine the idea of growth standards as a common yardstick for all populations. Weight depends on height. We became interested in whether also weight-for-height depends on height. First, we studied the age-group effect on weight-for-height. Thereafter, we tested the applicability of weight-for-height references in short and in historic populations. Sample and Methods: We analyzed body height and body weight and weight-for-height of 3795 healthy boys and 3726 healthy girls aged 2 to 5 years measured in East-Germany between 1986 and 1990. We chose contemporary height and weight charts from Germany, the UK, and the WHO growth chart and compared these with three geographically commensurable growth charts from the end of the 19th century. Results: We analyzed body height and body weight and weight-for-height of 3795 healthy boys and 3726 healthy girls aged 2 to 5 years measured in East-Germany between 1986 and 1990. We chose contemporary height and weight charts from Germany, the UK, and the WHO growth chart and compared these with three geographically commensurable growth charts of the end of the 19th century. Conclusion: Weight-for-height depends on age and sex and apart from the nutritional state, reflects body proportion and body built particularly during infancy and early childhood. Populations with a relatively short average height are prone to high values of weight-for-height for arithmetic reasons independent of the nutritional state. KW - growth standards KW - growth references KW - body mass index KW - nutritional status Y1 - 2022 U6 - https://doi.org/10.52905/hbph2021.3.28 SN - 2748-9957 VL - 2021 IS - 3, Summer School Supplement PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Scheffler, Christiane A1 - Rogol, Alan D. A1 - Iancu, Mirela A1 - Hanc, Tomasz A1 - Moelyo, Annang Giri A1 - Suchomlinov, Andrej A1 - Lebedeva, Lidia A1 - Limony, Yehuda A1 - Musalek, Martin A1 - Veldre, Gudrun A1 - Godina, Elena Z. A1 - Kirchengast, Sylvia A1 - Mumm, Rebekka A1 - Groth, Detlef A1 - Tutkuviene, Janina A1 - Böker, Sonja A1 - Ozer, Basak Koca A1 - Navazo, Barbara A1 - Spake, Laure A1 - Koziel, Slawomir A1 - Hermanussen, Michael T1 - Growth during times of fear and emotional stress BT - Proceedings of the 28th Aschauer Soiree, held at Potsdam, Germany, and online, November 14th 2020 JF - Human biology and public health N2 - Twenty-one scientists met for this year’s virtual conference on Auxology held at the University Potsdam, Germany, to discuss child and adolescent growth during times of fear and emotional stress. Growth within the broad range of normal for age and sex is considered a sign of good general health whereas fear and emotional stress can lead to growth faltering. Stunting is a sign of social disadvantage and poor parental education. Adverse childhood experiences affect child development, particularly in families with low parental education and low socioeconomic status. Negative effects were also shown in Indian children exposed prenatally and in early postnatal life to the cyclone Aila in 2009. Distrust, fears and fake news regarding the current Corona pandemic received particular attention though the effects generally appeared weak. Mean birth weight was higher; rates of low, very and extremely low birth weight were lower. Other topics discussed by the participants, were the influences of economic crises on birth weight, the measurement of self-confidence and its impact on growth, the associations between obesity, peer relationship, and behavior among Turkish adolescents, height trends in Indonesia, physiological neonatal weight loss, methods for assessing biological maturation in sportsmen, and a new method for skeletal age determination. The participants also discussed the association between acute myocardial infarction and somatotype in Estonia, rural-urban growth differences in Mongolian children, socio-environmental conditions and sexual dimorphism, biological mortality bias, and new statistical techniques for describing inhomogeneity in the association of bivariate variables, and for detecting and visualizing extensive interactions among variables. KW - stunting KW - birth weight KW - fear KW - emotional stress KW - economy KW - SEPE Y1 - 2021 U6 - https://doi.org/10.52905/hbph.v2.15 SN - 2748-9957 IS - 2 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Mumm, Rebekka A1 - Hermanussen, Michael T1 - A short note on the BMI and on secular changes in BMI JF - Human biology and public health N2 - Human size changes over time with worldwide secular trends in height, weight, and body mass index (BMI). There is general agreement to relate the state of nutrition to height and weight, and to ratios of weight-to-height. The BMI is a ratio. It is commonly used to classify underweight, overweight and obesity in adults. Yet, the BMI is inappropriate to provide any immediate information on body composition. It is accepted that the BMI is “a simple index to classify underweight, overweight and obesity in adults”. It is stated that “policies, programmes and investments need to be “nutrition-sensitive”, which means they must have positive impacts on nutrition”. It is also stated that “a need for policies that address all forms of malnutrition by making healthy foods accessible and affordable, while restricting unhealthy foods through fiscal and regulatory restrictions“. But these statements are neither warranted by arithmetic considerations, nor by historic evidence. Measuring the BMI is an appropriate screening tool for detecting an unusual weight-to-height ratio, but the BMI is an inappropriate tool for estimating body composition, or suggesting medical and health policy decisions. KW - body mass index KW - secular trend KW - weight-to-height ratio KW - malnutrition KW - obesity Y1 - 2021 U6 - https://doi.org/10.52905/hbph.v2.17 SN - 2748-9957 IS - 2 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Navazo, Bárbara A1 - Oyhenart, Evelia A1 - Dahinten, Silvia A1 - Mumm, Rebekka A1 - Scheffler, Christiane T1 - Decrease of external skeletal robustness (Frame Index) between two cohorts of school children living in Puerto Madryn, Argentina at the beginning of the 21st century JF - Journal of biological and clinical anthropology : Anthropologischer Anzeiger N2 - Background: It has been shown that modern life style with reduced physical activity can lead to lower bone accumulation. Also a decline trend in external skeletal robustness in children and young adolescents, measured by the Frame Index (FI), seems to have a parallel trend with the increase in overweight and obesity. Based on these findings we estimate that likely, the FI should be changed after a decade in the Argentinean population as well as in others population of the world. Thereby, the aim of the present study was to describe, using the FI, the pattern of external skeletal robustness in school children aged 6-14 years from two cohorts of Argentina (Puerto Madryn, Chubut) and to compare them with the European reference (Czech Republic, Germany, Poland and Russia). Methods: Elbow breadth and height of Puerto Madryn school children were collected in two cross-sectional studies conducted between 2001-2006 (cohort 1 = C1) and 2014-2016 (cohort 2 = C2). Percentiles (P) values, for males and females, from C1 and C2 were calculated combining the LMSmethod and its extension. A t-test has been used to compare, by age and sex, the FI values between the Argentinean cohorts and the European reference (ER). Then, in order to know the percentage of the variation of the percentiles values between cohorts, as well as with ER, percent differences between means (PDM%) were employed. Results: FI from Argentinean cohorts differed significantly from ER. Even more, C2 was not only smaller than ER, but also than C1. In males, C1-C2 showed significant differences at 6-8, 11 and 12 years and in females at all ages. Then, respect to ER each Argentinean cohort showed significant differences in males of C1 at 6, 12-14 years and in females at 6 and 11-14 years; and of C2, in both sexes, from 6 to 14 years. The PDM% values for elbow breadth of male were negative in ER-C1 in all percentiles analyzed; in ER-C2 positive (P3 and P50) and negative (P97) and C1-C2 recorded positive values. In females, elbow breadth showed negative values for ER-C1 (P50 and P97), and positive for the remaining values. Finally, height registered, in both sexes, negative values in ER-C1 (except P97 in females), ER-C2 and C1-C2. Conclusions: After ten years of the first study carried on in Puerto Madryn, school children show a negative trend in the external skeletal robustness. Additionally, the children of both Argentinean cohorts have lower values compared to the European reference, and mainly the actual cohort. This situation would be explained, in part, by the progressive increase over time of overweight and obesity as consequence, among others, of the change in the quantity and/or quality of the food that children have access to and with the physical activity they do at school and outside. KW - elbow breadth KW - height KW - skeletal robustness KW - school children KW - Argentina Y1 - 2020 U6 - https://doi.org/10.1127/anthranz/2020/1182 SN - 0003-5548 SN - 2363-7099 VL - 77 IS - 5 SP - 405 EP - 413 PB - Schweizerbart CY - Stuttgart ER - TY - JOUR A1 - Reimann, Anna A1 - Beyer, Rudolf A1 - Mumm, Rebekka A1 - Scheffler, Christiane T1 - Reference tables with centiles of limb to body height ratios of healthy human adults for assessing potential thalidomide embryopathy JF - Journal of biological and clinical anthropology : Anthropologischer Anzeiger ; Mitteilungsorgan der Gesellschaft für Anthropologie N2 - Background: Over 60 years ago the biggest drug catastrophe in Germany took place. The drug thalidomide, sold by the German pharmaceutical company Chemie Grunenthal GmbH starting in 1957 under the name "Contergan", caused severe birth defects in newborns. Chemie Grunenthal withdraw Contergan in 1961. Until nearly 30 years later in 1988 there were already over 10.000 children born with severe birth defects (e.g. dysmelia, amelia, congenital heart defect). Due to the high variability of the birth defects caused by thalidomide, later called thalidomide embryopathy, there is still no detailed information about the proportions of limbs. Aim: The aim is to develop reference centiles for limb measurements of men and women aged 19-70 years old. Method: For the calculation, data of healthy men and women (m = 2984, f = 2838) from former East Germany were used and centiles using the LMS-method were developed. Results: Centile tables for arm and leg length of men and women are presented in the results. The variability is small due to a homogeneous distribution of the measurements. A test with randomly chosen patient data shows that women under 171 cm stature and men under 180 cm stature can be assessed correctly. A severe shortening of limbs can be detected with this method. KW - thalidomide embryopathy KW - contergan KW - anthropometry KW - body proportions Y1 - 2019 U6 - https://doi.org/10.1127/anthranz/2019/0981 SN - 0003-5548 VL - 76 IS - 5 SP - 391 EP - 400 PB - Schweizerbart CY - Stuttgart ER - TY - JOUR A1 - Mumm, Rebekka A1 - Scheffler, Christiane T1 - Lack of evidence of nutritional influence on height in four low and middle-income countries JF - Journal of biological and clinical anthropology : Anthropologischer Anzeiger ; Mitteilungsorgan der Gesellschaft für Anthropologie N2 - ‘Nutrition influences height’ has been a common concept for the last decades. Recently, contradictory results occurred when studying the effectiveness of nutritional interventions, questioning the interaction of nutrition and height. Therefore, we hypothesize that, independently of population/country, nutrition does not affect height in children and adolescents. We analyzed data from the study “Young Lives” which was performed in Ethiopia, India, Peru, and Vietnam to describe the health situation of children. We used linear mixed effect models to analyze the influence of nutrition on height. Furthermore, we used Structural Equation Modeling (SEM) to test if the commonly assumed hypothetical interaction of height and nutrition can be supported by data from low and middle-income countries. Estimates for nutrition on height of linear mixed effect models were about zero and randomly significant or non-significant in all analyzed countries. Furthermore, SEM led to the rejection of the ‘nutrition influences height’-hypothesis, as data did not support the models based on this hypothesis. We do not find evidence for a nutritional influence on height in children and adolescents from low and middle-income countries. The widespread assumption that inadequate diet is reflected in short stature, which all modern nutritional interventions are based on, needs to be critically reviewed. KW - nutrition KW - height KW - children KW - low and middle-income Y1 - 2019 U6 - https://doi.org/10.1127/anthranz/2019/0988 SN - 0003-5548 VL - 76 IS - 5 SP - 421 EP - 432 PB - Schweizerbart CY - Stuttgart ER - TY - JOUR A1 - Hermanussen, Michael A1 - Pulungan, Aman B. A1 - Scheffler, Christiane A1 - Mumm, Rebekka A1 - Rogol, Alan D. A1 - Pop, Raluca A1 - Swanson, James M. A1 - Sonuga-Barke, Edmund A1 - Reimann, Anna A1 - Siniarska-Wolanska, Anna A1 - Musalek, Martin A1 - Bogin, Barry A1 - Boldsen, Jesper L. A1 - Tassenaar, (Vincent) A1 - Groth, Detlef A1 - Liu, Yuk-Chien A1 - Meigen, Christof A1 - Quanjer, Bjorn A1 - Thompson, Kristina A1 - Ozer, Baak Koca A1 - Bryl, Ewa A1 - Mamrot, Paula A1 - Hanc, Tomasz A1 - Koziel, Slawomir A1 - Soderhall, Jani A1 - Gomula, Aleksandra A1 - Banik, Sudip Datta A1 - Roelants, Mathieu A1 - Veldre, Gudrun A1 - Lieberman, Leslie Sue A1 - Sievert, Lynnette Leidy T1 - Meeting Reports BT - The Role of Beliefs and Perception on Body Size. Proceedings of the 26th Aschauer Soiree, Held at Aschauhof, Altenhof, Germany, May 26th, 2018 JF - Pediatric Endocrinology Reviews N2 - Thirty-one scientists met at Aschauhof, Germany to discuss the role of beliefs and self-perception on body size. In view of apparent growth stimulatory effects of dominance within the social group that is observed in social mammals, they discussed various aspects of competitive growth strategies and growth adjustments. Presentations included new data from Indonesia, a cohort-based prospective study from Merida, Yucatan, and evidence from recent meta-analyses and patterns of growth in the socially deprived. The effects of stress experienced during pregnancy and adverse childhood events were discussed, as well as obesity in school children, with emphasis on problems when using z-scores in extremely obese children. Aspects were presented on body image in African-American women, and body perception and the disappointments of menopause in view of feelings of attractiveness in different populations. Secular trends in height were presented, including short views on so called 'racial types' vs bio-plasticity, and historic data on early-life nutritional status and later-life socioeconomic outcomes during the Dutch potato famine. New tools for describing body proportions in patients with variable degrees of phocomelia were presented along with electronic growth charts. Bio-statisticians discussed the influence of randomness, community and network structures, and presented novel tools and methods for analyzing social network data. KW - Body size KW - Social group KW - Social network KW - Body perception KW - Competitive growth strategies KW - Growth adjustment Y1 - 2019 U6 - https://doi.org/10.17458/per.vol16.2019.hps.mr.26achauersoiree SN - 1565-4753 VL - 16 IS - 3 SP - 383 EP - 400 PB - Medical Media CY - Netanya ER -