The mysterious trend in American heights in the 20th century

Pharmacogenomics and pediatric drug development: science and political power. A narrative review

INTRODUCTION

Pharmacogenomics (PGx) investigates how genomes control enzyme expression. Developmental pharmacology (DP) describes the temporal sequence of enzymes impacting absorption, distribution, metabolism, and excretion (ADME) of food and drugs.

AREAS COVERED

US and European Union (EU) legislation facilitate and/or enforce pediatric studies for all new drugs, called overall 'pediatric drug development' (PDD). DP and PDD look at patients' chronological age, but oscillate between legal and physiological meanings of the term 'child.' Children's bodies become mature with puberty.

EXPERT OPINION

Decades after first DP observations in babies, PGx offers a better understanding of the variability of safety and efficacy of drugs, of the process of aging, and of shifting enzyme patterns across aging. We should rethink and revise outdated interpretations of ADME changes in minors. The Declaration of Helsinki forbids pointless studies that some pediatric researchers and regulatory agencies, more so the EMA than the FDA, demand pointless pediatric studies is regrettable. Medicine needs to differentiate between legal and physiological meanings of the term 'child' and should use objective measures of maturity.

Did pediatric drug development advance epilepsy treatment in young patients? It is time for new research goals

Modern drugs have changed epilepsy, which affects people of all ages. However, for young people with epilepsy, the framework of drug development has stalled. In the wake of the thalidomide catastrophe, the misconception emerged that for people < 18 years of age drugs, including antiseizure medications (ASMs), need separate proof of efficacy and safety, overall called "pediatric drug development". For ASMs, this has changed to some degree. Authorities now accept that ASMs are effective in < 18 years as well, but they still require "extrapolation of efficacy," as if minors were another species. As a result, some of the pediatric clinical epilepsy research over the past decades was unnecessary. Even more importantly, this has hampered research on meaningful research goals. We do not need to confirm that ASMs work before as they do after the 18th birthday. Instead, we need to learn how to prevent brain damage in young patients by preventing seizures and optimize ASMs' uses. Herein we discuss how to proceed in this endeavor.

Intergenerational change in anthropometry of children and adolescents in the New Delhi Birth Cohort

BACKGROUND

A comparison of the anthropometry of children and adolescents with that of their parents at the same age may provide a more precise measure of intergenerational changes in linear growth and body mass index (BMI).

METHODS

New Delhi Birth Cohort participants (F1), born between 1969 and 1972, were followed up for anthropometry at birth and at 6-monthly intervals until 21 years of age. At variable intervals 1447 children, aged 0-19 years (F2) and born to 818 F1 participants, were measured (weight and height), providing 2236 sets of anthropometries. Intergenerational changes (F2-F1) in height and BMI [absolute and standard deviation (SD) units] were computed by comparing children with their parents at corresponding ages.

RESULTS

F2 children were taller (P < 0.001) than their parents at corresponding ages; the increase {mean [95% confidence interval)CI)] World Health Organization SD units} was 0.97 (0.83, 1.11), 1.21 (1.10, 1.32), 1.09 (0.98, 1.19), 1.10 (1.00, 1.21) and 0.75 (0.65, 0.85) for age categories of 0-5, 5-7.5, 7.5-10, 10-12.5 and >12.5 years, respectively. In absolute terms, this increase ranged from 3.5 cm (0-5-year-olds) to 7.5 cm (10-12.5-year-olds). The corresponding increases in BMI SD scores were 0.32 (0.18, 0.47), 0.60 (0.45, 0.75), 1.13 (0.99, 1.27), 1.30 (1.15, 1.45) and 1.00 (0.85, 1.15), respectively. The absolute BMI increase ranged from 1-3 kg/m2 at >5 years age to ∼3 kg/m2 at >10-years of age. The intergenerational increases were comparable in both sexes, but were greater in children born and measured later. A positive change in socioeconomic status was associated with an increase in height across the generations.

CONCLUSIONS

Children and adolescents, throughout the ages 0-19 years, have become considerably taller and have a higher BMI than their parents at corresponding ages in an urban middle-class Indian population undergoing socioeconomic improvements.

COVID-19 and Treatment and Immunization of Children-The Time to Redefine Pediatric Age Groups is Here

Children are infected with coronavirus disease 2019 (COVID-19) as often as adults, but with fewer symptoms. During the first wave of the COVID-19 pandemic, multisystem inflammatory syndrome (MIS) in children (MIS-C), with symptoms similar to Kawasaki syndrome, was described in young minors testing positive for COVID-19. The United States (US) Centers for Disease Control and Prevention (CDC) defined MIS-C as occurring in <21-year-olds, triggering hundreds of PubMed-listed papers. However, postpubertal adolescents are no longer children biologically; the term MIS-C is misleading. Furthermore, MIS also occurs in adults, termed MIS-A by the CDC. Acute and delayed inflammations can be triggered by COVID-19. The 18th birthday is an administrative not a biological age limit, whereas the body matures slowly during puberty. This blur in defining children leads to confusion regarding MIS-C/MIS-A. United States and European Union (EU) drug approval is handled separately for children, defined as <18-year-olds, ascribing non-existent physical characteristics up to the 18th birthday. This blur between the administrative and the physiological meanings for the term child is causing flawed demands for pediatric studies in all drugs and vaccines, including those against COVID-19. Effective treatment of all conditions, including COVID-19, should be based on actual physiological need. Now, the flawed definition for children in the development of drugs and vaccines and their approval is negatively impacting prevention and treatment of COVID-19 in minors. This review reveals the necessity for redefining pediatric age groups to rapidly establish recommendations for optimal prevention and treatment in minors.

Body proportions according to stature groups in elite athletes

The aim of this study was to investigate whether body proportions change as stature increases in elite Spanish athletes. The sample includes a total of 2,030 participants, comprised of 1,357 adult males, and 673 adult females. The male athletes were classified into five groups by stature, and the female athletes were classified separately into four stature groups. Ten anthropometric measurements were collected, and eleven body proportions were calculated. The body proportions with significant differences between stature groups in males were relative arm length (0.53-1.60%), relative forearm length (0.69-2.08%), relative thigh length (1.17-1.56%), relative tibial length (1.37-6.39%), cormic index (-0.94 - -4.49%), Manouvrier index (1.60-9.60%), and crural index (1.05-4.79%). In females, the body proportions with significant differences were relative forearm length (1.43%), relative thigh length (1.94-3.88%), relative tibial length (2.74-4.56%), cormic index (-0.74 - -3.72%), and Manouvrier index (1.97-8.71%). The distal parts of the upper and lower limbs increase proportionally as stature increases, whereas relative hand and foot lengths, which are the most distal parts of the extremities, remain constant in elite athletes.

Assessing the effects of autarchic policies on the biological well-being: Analysis of deviations in cohort male height in the Valencian Community (Spain) during Francoist regime

This article aims to assess the impact of autarchic policies on the biological dimensions of human well-being during Francoist regime in Spain. This is done by examining the nutritional status of the population through the study of male adult heights. Our case study is the Valencian Community with the focus on the period 1940-59 which witnessed the implementation of such policies. The heights of 21-year old draftees born between 1900 and 1954 from nine municipalities (N = 87,510) were analyzed in the light of inter-cohort deviations from a secular trend established for cohorts that were not exposed to autarchy-related hardships. Height was regressed on infant mortality as a way to control for infection and therefore approach the net effect of nutrition on height outcomes. Contrarily to what was displayed by cohort height trends in themselves, the results reveal a significant worsening of the nutritional status of the male population at the time. Deviations from the expected height trend across municipalities ranged between -0.5 and -3.4 mm per year. The effects of malnutrition are found to be larger among cohorts born in the period 1920-34 in coherence with a longer exposure to autarchy hardships during adolescence. Pre-autarchy nutrition levels observed among the cohorts of 1900-14 were not regained until the cohorts 1945-49. The results also show that malnutrition had an unequal impact with the large industrial towns of our sample experiencing the poorest height outcomes. Overall, these results invite to revise conclusions obtained from the sole evidence of height trends and they question the efficiency of intervention policies implemented in Spain during the 1940s.

Prediction of adolescent pelvis development using femoral head and acetabulum growth in a longitudinal radiographic study

INTRODUCTION

Adolescent total hip arthroplasty (THA) is guarded partially due unclarity as to when pediatric hip joints reach full development. This study sought to identify when maximum acetabular and femoral head diameters are achieved with relation to chronological and skeletal age.

MATERIALS AND METHODS

Consecutive femoral head and acetabular diameters were measured in a random sample of 54 female and 78 male subjects, which were queried from a historical collection of annual radiographs of children. Femoral head and triradiate physeal plates were scored according to Oxford bone parameters.

RESULTS

At 14 years females had femoral diameters of 4.16 +/- 0.23 cm and acetabular diameters of 5.15 +/- 0.30 cm. At 16 years males had femoral diameters of 4.85 +/- 0.30 cm and acetabular diameters of 5.90 +/- 0.35 cm. In the year following maximal femoral Oxford scores, no significant change was seen in femur and acetabulum diameters in females and in femur diameters in males. In the year following maximal acetabular Oxford scores, there was a significant increase in both femur and acetabulum diameters in both females and males.

CONCLUSIONS

Females on average reach maximum pelvis maturity at 14 years and males reach maximum pelvis maturity at 16 years. A closed femoral head was found to be a good marker of full hip growth, while a closed triradiate was not. This study provides anatomical data for surgeons to consider in assessing risk factors of THA failure in adolescents.

Aktuelle Normwerte der Organgewichte und -indizes für die rechtsmedizinische Praxis, Teil 2

Einleitung

Die Obduktion nimmt einen wichtigen Stellenwert in der Medizin ein, da sie nicht nur der Klärung der Todesart und -ursache eines Verstorbenen dient, sondern auch zum Verständnis der Pathophysiologie von Erkrankungen beiträgt. In diesem zweiten Teil der Studie wurden aktuelle Normwerte für das Gewicht für die folgenden adulten Organe entwickelt: Leber, Lunge, Milz, Nieren. Zudem wurden Zusammenhänge zwischen Organgewichten und der Todesart untersucht.

Material und Methoden

Die im Dreijahreszeitraum von 2011 bis 2013 im Institut für Rechtsmedizin in Frankfurt am Main durchgeführten Obduktionen wurden retrospektiv ausgewertet. Die statistischen Berechnungen erfolgten mithilfe des Programmes „BiAS. für Windows“ (epsilon-Verlag GbR, Hochheim-Darmstadt, Deutschland).

Ergebnisse

Folgende Normwerte bzw. -bereiche wurden an der Studienpopulation erhoben: Leber 1047,0–2740,0 g (♂, n = 191) bzw. 749,0–2182,0 g (♀, n = 115), linke Lunge 230,0–840,0 g (♂, n = 119) bzw. 186,8–891,3 g (♀, n = 97), rechte Lunge 249,3–1005,8 g (♂, n = 116) bzw. 215,3–907,5 g (♀, n = 100), Milz 55,0–373,2 g (♂, n = 306) bzw. 50,0–355,0 g (♀, n = 204), linke Niere 110,0–255,0 g (♂, n = 258) bzw. 71,8–215,0 g (♀, n = 137), rechte Niere 100,0–270,0 g (♂, n = 266) bzw. 75,0–212,1 g (♀, n = 140). Für die am stärksten mit Organgewichten korrelierenden Körpermaße, nämlich Body-Mass-Index (BMI), Körperoberfläche („body surface area“, BSA) und Körpergewicht, wurden nach Subgruppen getrennte Normwerte ermittelt. Ein signifikanter Unterschied des Organgewichtes je nach Todesart lag bei Männern bei der Milz und bei den Nieren vor. Bei Frauen war bei keinem der Organe ein von der Todesart abhängiger signifikanter Gewichtsunterschied feststellbar. Außerdem wurden Organindizes entwickelt, mittels derer der Anwender berechnen kann, ob ein Organgewicht, Körpermaßen bzw. Alter entsprechend, im Normbereich liegt.

Diskussion

Organgewichte unterliegen wie Körpermaße einem säkularen Trend, welcher jedoch nicht linear und für jedes Organ individuell verläuft. Für die Auswertung von Organgewichten im Rahmen der Obduktion werden deshalb aktuelle, an einer vergleichbaren Population erhobene Normtabellen benötigt. Bei deren Erstellung können sowohl Fälle mit natürlichem als auch mit nichtnatürlichem Tod unter weitestgehendem Ausschluss pathologisch veränderter Organe herangezogen werden.

In the land of the blind, the one‐eyed man is king

A cautionary note is reported on the results and conclusions of McCrae et al. (this issue). The main counter argument to a straightforward interpretation of mean differences at a national level is the arbitrary nature of the metrics for personality traits. It is argued that this fundamental property lies behind potential threats to the interpretation of mean scores, such as frame‐of‐reference and accessibility effects. An empirical example of how accessibility can also have an influence on correlations is reported. The main message is that one should be very cautious in assuming that mean personality self‐reports are necessarily more accurate than national stereotypes. Copyright © 2007 John Wiley & Sons, Ltd.

Ethical Issues in Pediatric Regulatory Studies Involving Placebo Treatment

Separate pediatric studies for antiepileptic drugs (AEDs) emerged with general separate drug approval in children and were defined by the U.S. Food and Drug Administration (FDA) as <17 years and by the European Union (EU) as <18 years. These administrative age limits are necessary in pediatrics, but they correspond variably with the physiological maturity of young patients and are not helpful for therapeutic decisions or as study inclusion criteria. AEDs are often effective for partial onset seizures (POS) in 2 to 17-year-olds as well as in ≥18-year-olds, if dosed correctly. Separate pediatric AED studies assume no difference between the legal and the physiological meaning of the word “child.” While the FDA now accepts efficacy of AEDs in POS in children ≥2 years, the EU still requires separate “pediatric” studies. For retigabine it waived all pediatric studies after having required 20 such studies over several years. We feel the current regulation creates a situation where many studies in children are done unnecessarily; we question the ethics of such an approach, which in our view, is morally wrong. Critical publications contributed to the FDA's shift of opinion for AEDs in POS but did not address the blur of different meanings of the word “child.”

Delay in Growth in Adolescents: Clinical Validation of a Proposed Nursing Diagnosis

PURPOSE

This study aims to analyse the accuracy of clinical indicators of the proposed diagnosis of delayed growth in school-aged adolescents.

DESIGN AND METHODS

This is a diagnostic accuracy study of 385 adolescents in public schools from July to September 2017 that aimed to assess the accuracy of clinical indicators of the proposed nursing diagnosis of delayed growth; the sensitivity and specificity values were calculated using latent class analysis.

RESULTS

Growth velocity less than expected was associated with sensitivity and specificity. The clinical indicator short stature for age and sex showed sensitivity. Low weight for age and sex, stature below genetic target and delayed sexual maturation were specific indicators.

CONCLUSION

In a sample of adolescents in public schools in northeastern Brazil, a set of five clinical indicators best indicated delayed growth in adolescents. Two clinical indicators showed sensitivity, and four clinical indicators showed specificity.

PRACTICE IMPLICATIONS

This study contributes to refining the diagnostic proposition of delayed growth in adolescents. Accurate measures for nursing diagnoses can help paediatric nurse practitioners confirm or exclude this diagnosis in adolescents with a similar profile.

The association between obesity and secular trend of stature: a nationwide study of 2.8 million adolescents over five decades

BACKGROUND/OBJECTIVES

It is unclear whether adolescent obesity is associated with limited linear growth. We assessed this association in a nationwide sample of adolescents.

METHODS

We conducted a population-based, study of 2,785,227 Israeli adolescents (60% males) who were examined before military service since 1967 through 2015. Height and weight were measured along with assessment of medical status at age 17.4 ± 0.4 years. The secular trend of height was plotted using United States Center for Disease Control (US CDC) age- and sex-adjusted BMI percentile groups. We accounted for health status at enrollment and computed the expected height based on parental data that was available for 512,978 examinees.

RESULTS

Over five decades, the mean height increased by 3.1 cm among males, but remained unchanged among females. Among males, gain in height was attained predominantly during the first 25 years and has stabilized since. Males with obesity were taller than their normal-weight and underweight counterparts. Underweight girls had a prominent increase in mean height during the first two decades, exceeding the mean height of their counterparts with obesity by over 2 cm. There was a gradual decrease in the difference between measured and expected height in males and females regardless of BMI status, with the exception of the underweight females who achieved consistently higher stature than expected (≥3 cm).

CONCLUSIONS

During five decades, excessive BMI was not a limiting factor in growth potential compared with normal BMI in both sexes. The only group that exceeded its growth potential, when accounting for expected mid-parental height, were underweight females with unimpaired health.

Birth Intervals and Health in Adulthood: A Comparison of Siblings Using Swedish Register Data

A growing body of research has examined whether birth intervals influence perinatal outcomes and child health as well as long-term educational and socioeconomic outcomes. To date, however, very little research has examined whether birth spacing influences long-term health. We use contemporary Swedish population register data to examine the relationship between birth-to-birth intervals and a variety of health outcomes in adulthood: for men, height, physical fitness, and the probability of falling into different body mass index categories; and for men and women, mortality. In models that do not adjust carefully for family background, we find that short and long birth intervals are clearly associated with height, physical fitness, being overweight or obese, and mortality. However, after carefully adjusting for family background using a within-family sibling comparison design, we find that birth spacing is generally not associated with long-term health, although we find that men born after very long birth intervals have a higher probability of being overweight or obese in early adulthood. Overall, we conclude that birth intervals have little independent effect on long-term health outcomes.

Positive Secular Trend in Slovak Population Urges on Updates of Functional Dimensions of Furniture

The presented study is focused on the evaluation of the changes in weight and height of the adult population in Slovakia to provide updated information on the secular growth trend. The main objective was to identify and quantify the pace of gradual changes in the dimensions of the Slovak adult population, which is key ergonomic information for multiple disciplines. The measurements of weights, heights and body mass indices of the current adult population of Slovakia ranging from 26 to 94 years of age that were obtained in period 1993–2017 were compared with a sample of students studying at four Slovak universities during the same years (aged 18 to 25). The increase of mean heights was app. 0.104–0.203 cm per one year (or app. 1–2 cm per decade) for males and app. 0.031–0.178 cm per one year (or app. 0.3–1.8 cm per decade) for females was statistically confirmed at different age classes covering the age structure of the whole adult population. The positive secular height trends were manifested in weight and BMI increases too. The changes in means and variation of distributions of selected variables also cause changes in quantile values. For example, the 95% quantiles of heights derived for the period 1993–2003 only cover 92–93% of the heights in the current population. This fact could have a major impact on proposals for optimal and safe arrangement of work, residential and non-residential space, including the furniture production.

Prospective longitudinal study of the pregnancy DNA methylome: the US Pregnancy, Race, Environment, Genes (PREG) study

PURPOSE

The goal of the Pregnancy, Race, Environment, Genes study was to understand how social and environmental determinants of health (SEDH), pregnancy-specific environments (PSE) and biological processes influence the timing of birth and account for the racial disparity in preterm birth. The study followed a racially diverse longitudinal cohort throughout pregnancy and included repeated measures of PSE and DNA methylation (DNAm) over the course of gestation and up to 1 year into the postpartum period.

PARTICIPANTS

All women were between 18 and 40 years of age with singleton pregnancies and no diagnosis of diabetes or indication of assisted reproductive technology. Both mother and father had to self-identify as either African-American (AA) or European-American (EA). Maternal peripheral blood samples along with self-report questionnaires measuring SEDH and PSE factors were collected at four pregnancy visits, and umbilical cord blood was obtained at birth. A subset of participants returned for two additional postpartum visits, during which additional questionnaires and maternal blood samples were collected. The pregnancy and postpartum extension included n=240 (AA=126; EA=114) and n=104 (AA=50; EA=54), respectively.

FINDINGS TO DATE

One hundred seventy-seven women (AA=89, EA=88) met full inclusion criteria out of a total of 240 who were initially enrolled. Of the 63 participants who met exclusion criteria after enrolment, 44 (69.8%) were associated with a medical reason. Mean gestational age at birth was significantly shorter for the AA participants by 5.1 days (M=272.5 (SD=10.5) days vs M=277.6 (SD=8.3)).

FUTURE PLANS

Future studies will focus on identifying key environmental factors that influence DNAm change across pregnancy and account for racial differences in preterm birth.

Is "Latin American" population-specific? Testing sex discriminant functions from the Mexican tibia on a Chilean sample

Latin American populations are traditionally reported as one ancestral group in the forensic anthropology literature. However, this study illustrates the need for population-specific methodologies for ancestral groups that are considered Latin American. This project evaluated the accuracy of the sex estimation discriminant function created from the tibia of a Mexican population, when applied to a Chilean population. The maximum distal epiphyseal breadth (MDEB) and the anterior-posterior diameter at the nutrient foramen (APDNF) were measured on 203 tibiae (108 males and 95 females) from the Subactual Skeletal Collection at the University of Chile. The individuals ranged in age from 20 to 96 years old. When the Mexican discriminant function was applied to the Chilean population, accuracy rates ranged from 76.0% (males) to 85.0% (females). Mean tibial size comparisons were made to a Mexican, Croatian, White South African, archaeological Hispanic, and North Indian population and showed some significant differences between the variables measured. Population-specific discriminant functions were created for the Chilean population with overall sex classification accuracy rates of 71.4% (MDEB only) to 89.2% (MDEB and APDNF). This study illustrates the need for population-specific and temporally-specific discriminant functions for estimation of sex from the tibia.

Secular Trends on Birth Parameters, Growth, and Pubertal Timing in Girls with Turner Syndrome

BACKGROUND

Whether children with chromosomal disorders of growth and puberty are affected by secular trends (STs) as observed in the general population remains unanswered, but this question has relevance for expectations of spontaneous development and treatment responses.

OBJECTIVES

The aim of the study was to evaluate STs in birth parameters, growth, and pubertal development in girls with Turner syndrome (TS).

STUDY DESIGN

Retrospective analysis of KIGS data (Pfizer International Growth Database). We included all TS patients who entered KIGS between 1987 and 2012 and were born from 1975 to 2004, who were prepubertal and growth treatment naïve at first entry (total number: 7,219). Pretreatment height and ages at the start of treatment were compared across 5-year birth year groups, with subgroup analyses stratified by induced or spontaneous puberty start.

RESULTS

We observed significant STs across the birth year groups for birth weight [+0.18 SD score (SDS), p < 0.001], pretreatment height at mean age 8 years (+0.73 SDS, p < 0.001), height at the start of growth hormone (GH) therapy (+0.38 SDS, p < 0.001) and start of puberty (+0.42 SDS, p < 0.001). Spontaneous puberty onset increased from 15 to 30% (p < 0.001). Mean age at the start of GH treatment decreased from 10.8 to 7.4 years (-3.4 years; p < 0.001), and substantial declines were seen in ages at onset of spontaneous and induced puberty (-2.0 years; p < 0.001) and menarche (-2.1 years; p < 0.001).

CONCLUSION

Environmental changes leading to increased height and earlier and also more common, spontaneous puberty are applicable in TS as in normal girls. In addition, greater awareness for TS may underlie trends to earlier start of GH therapy and induction of puberty at a more physiological age.

Secular trends in height, weight and body mass index of primary school children in Turkey between 1993 and 2016

BACKGROUND

The aim of the study was to analyze the secular trends in height, weight and body mass index (BMI) of children in a Turkish primary school in a 23-year time interval.

METHODS

The height, weight and BMI of 1099 children between 7 and 15 years old were measured. Data were compared to those of children of the same ages from previous measurements carried out in 1993 (867 children) and in 2003 (1214 children) in the same school. The changes in weight, height and BMI were determined and analyzed statistically.

RESULTS

Weight increments between 7.7 and 16.2 kg/23 years and height increments between 1.1 and 8.3 cm/23 years were observed in boys. For girls, weight increments between 6.5 and 13.4 kg/23 years and height increments between 1.3 and 7.2 cm/23 years were indicated. Usually, there were significant height increments between 1993 and 2016 in both genders. However, there were no significant differences in height between 2003 and 2016 for all age groups. Furthermore, there were significant differences in BMI measurements in all age and gender groups between 1993 and 2016.

CONCLUSIONS

The secular ascending trend in height seems to stop between 2003 and 2016; however, increments in weight and mean BMI tend to continue in Turkish primary school children and adolescents.

Are We Reaching the Limits of Homo sapiens?

Echoing scientific and industrial progress, the Twentieth century was an unprecedented period of improvement for human capabilities and performances, with a significant increase in lifespan, adult height, and maximal physiological performance. Analyses of historical data show a major slow down occurring in the most recent years. This triggered large and passionate debates in the academic scene within multiple disciplines; as such an observation could be interpreted as our upper biological limits. Such a new phase of human history may be related to structural and functional limits determined by long term evolutionary constraints, and the interaction between complex systems and their environment. In this interdisciplinary approach, we call into question the validity of subsequent forecasts and projections through innovative and related biomarkers such as sport, lifespan, and height indicators. We set a theoretical framework based on biological and environmental relevance rather than using a typical single-variable forecasting approach. As demonstrated within the article, these new views will have major social, economical, and political implications.

Advantages of later motherhood

BACKGROUND

In high-income countries childbearing has been increasingly postponed since the 1970s and it is crucial to understand the consequences of this demographic shift. The literature has tended to characterize later motherhood as a significant health threat for children and parents.

OBJECTIVES

We contribute to this debate by reviewing recent evidence suggesting that an older maternal age can also have positive effects.

MATERIALS

Literature linking the age at parenthood with the sociodemographic characteristics of the parents, with macrolevel interactions, and with subjective well-being.

METHODS

Comprehensive review of the existing literature.

RESULTS

Recent studies show that there can also be advantages associated with later motherhood. First, whilst in past older mothers had low levels of education and large families, currently older mothers tend to have higher education and smaller families than their younger peers. Consequently, children born to older mothers in the past tended to have worse outcomes than children born to younger mothers, whilst the opposite is true in recent cohorts. Second, postponement of childbearing means that the child is born at a later date and in a later birth cohort, and may benefit from secular changes in the macroenvironment. Evidence shows that when the positive trends in the macroenvironment are strong they overweigh the negative effects of reproductive ageing. Third, existing studies show that happiness increases around and after childbirth among older mothers, whereas for younger mothers the effect does not exist or is short-lived.

CONCLUSION

There are important sociodemographic pathways associated with postponement of childbearing which might compensate or even more than compensate for the biological disadvantages associated with reproductive ageing.

Sex Differences in the Impact of Thinness, Overweight, Obesity, and Parental Height on Adolescent Height

PURPOSE

The secular trend of increasing weight may lead to a decline in height gain compared with the genetic height potential. The impact of weight on height in healthy male and female adolescents compared with their genetic height was assessed.

METHODS

Height and weight were measured in Israeli adolescent military recrutees aged 16-19 years between 1967 and 2013. The study population comprised 355,229 recrutees for whom parental height measurements were documented. Subjects were classified into four body mass index percentile groups according to the U.S. Centers for Disease Control and Prevention body mass index percentiles for age and sex:<5th (underweight), 5th-49th (low-normal), 50th-84th (high-normal), and ≥85th (overweight-obese). Short stature was defined as height ≤ third percentile and tall stature as height ≥ 90th percentile for age and sex.

RESULTS

Overweight-obese females had a 73% increased risk for short stature (odds ratio [OR]: 1.73, 95% confidence interval [CI] = 1.51-1.97, p < .001). Conversely, underweight females had a 56% lower risk of short stature (OR: .44, 95% CI = .28-.70, p = .001) and a twofold increased risk for being tall (OR: 2.08, 95% CI = 1.86-2.32, p < .001). Overweight-obese males had a 23% increased risk of being short (OR: 1.23, 95% CI = 1.10-1.37, p < .001). Underweight females were on average 4.1 cm taller than their mid-parental height.

CONCLUSIONS

Overweight-obese males and females had an increased risk of being short, and underweight females were significantly taller compared with their genetic height. The significantly increased height among underweight healthy females may reflect a potential loss of height gain in overweight-obese females.

Deriving individualised /r/ targets from the acoustics of children's non-rhotic vowels

In visual-acoustic biofeedback for rhotic errors, learners are guided to match the third formant (F3) location to a visual target on a real-time acoustic spectrum. As the acoustic properties of correct English /r/differ across speakers, this study aimed to improve target selection by investigating the validity of individualised targets derived from children's non-rhotic vowels. A previously proposed prediction formula was adjusted using data from a child normative sample and tested in two groups of children. Study 1 found that predicted values were unexpectedly higher than actual F3 values in children whose /r/ errors had been remediated. To understand this discrepancy, Study 2 applied the formula to typically developing children and found that predicted values were also higher than actual F3 values, suggesting that different normative data might better represent the current samples. An updated formula is proposed, which can be used to generate individualised targets within acoustic biofeedback applications.

Acetabular rim length: an anatomical study to determine reasonable graft sizes for labral reconstruction

The purpose of this article is to determine normative values for the length of the acetabular rim and detect differences between gender, age, ethnicity, height and leg length. Six measurements were taken on the acetabular rim of 143 cadaveric skeleton specimens (286 acetabula) using a coordinate-measuring device: circumferential (excluding acetabular notch), anterior inferior iliac spine (AIIS)-anterior, AIIS-posterior, 12-3 o'clock, 12-9 o'clock and 11-5 o'clock. Museum specimen height data and leg length data from a previous study were recorded for 109 of 143 specimens. Intraclass correlation coefficients were calculated. Student t-tests compared mean values. Multiple regression analysis was used to determine the relationship between acetabular rim length and gender, age, ethnicity, height and leg length. The average acetabular rim length in males for circumferential, AIIS-anterior, AIIS-posterior, 12-3, 12-9 and 11-5 o'clock were 15.8, 4.2, 11.7, 4.9, 4.7 and 9.5 cm, respectively; and for females: 13.7, 3.7, 10.0, 4.3, 4.1 and 8.3 cm, respectively. Intraclass correlation coefficients were 0.953, 0.930, 0.958, 0.857, 0.913 and 0.951, respectively, for each measurement. All six measurements were significantly larger for males (P < 0.001). Multiple regression analysis demonstrated a significant relationship between gender and rim length for all six measurements (P < 0.001) and between height and leg length and acetabular rim length for five of the six measurements exclusive of AIIS-anterior (P < 0.001). No significant trends between age or ethnicity and rim length were found. Average acetabular rim lengths were established. The acetabular rim is significantly longer in males and correlates with height and leg length. Age and ethnicity do not appear to be significant predictors of acetabular rim length. Normative values for acetabular rim lengths may assist in hip preservation surgery.

Estimating Heritability from Nuclear Family and Pedigree Data

Heritability is a measure of familial resemblance. Estimating the heritability of a trait could be one of the first steps in the gene mapping process. This chapter describes how to estimate heritability for quantitative traits from nuclear and pedigree data using the ASSOC program in the Statistical Analysis in Genetic Epidemiology (S.A.G.E.) software package. Estimating heritability rests on the assumption that the total phenotypic variance of a quantitative trait can be partitioned into independent genetic and environmental components. In turn, the genetic variance can be divided into an additive (polygenic) genetic variance, a dominance variance (nonlinear interaction effects between alleles at the same locus) and an epistatic variance (interaction effects between alleles at different loci). The last two are often assumed to be zero. The additive genetic variance represents the average effects of individual alleles on the phenotype and reflects transmissible resemblance between relatives. Heritability in the narrow sense (h ² ) refers to the ratio of the additive genetic variance to the total phenotypic variance. Heritability is a dimensionless population-specific parameter. ASSOC estimates association parameters (regression coefficients) and variance components from family data. ASSOC uses a linear regression model in which the total residual variance is partitioned, after regressing on covariates, into the sum of random components such as an additive polygenic component, a random sibship component, random nuclear family components, a random marital component, and an individual-specific random component. Assortative mating, nonrandom ascertainment of families, and failure to account for key confounding factors may bias heritability estimates.

Diachronic changes in size and shape of human proximal tibia in Central Europe during the latest 1200 years

During the past twelve centuries, the stature of Central European inhabitants has increased significantly with corresponding changes in the size of lower limb bones. The aim of our study was to determine whether these changes have occurred strictly in relation to size or if the shape of skeletal structures has been altered simultaneously. Diachronic size and shape changes in the proximal part of tibia in a Central European population (Czech Republic) were studied using geometric morphometrics (principal components analysis, Hotelling's test, linear discriminant analysis). The study sample consisted of 183 three-dimensional (3D) models of adult tibiae dating to the early Middle Ages (N=65), early 20th century (N=60), and from a modern Czech population (N=57). A positive secular trend in size manifested only between the two modern Czech populations (the 20th century vs. the 21st century), a time range shorter than one century. By contrast, landmark-based shape analyses revealed significant differences in tibial morphology over the three periods covered in the study. In particular, progressive changes were observed in the position of tibial tuberosity (shifted medially), the inclination of the line connecting tuberosity with anterior edge of the tibial plateau (sloped down), the reshaping of the lower back condyle boundary (shifted posteriorly), and reshaping of the medial contour of the medial condyle (shifted anteriorly). Changes in the shape of the proximal tibial extremity across the chronologically distinct groups indicated the existence of discreet but convincing microevolutionary trends involving this anatomical structure.

Secular change of sexually dimorphic cranial variables in Euro-Americans and Germans

Crania are a reliable source for sex estimation in Euro-Americans, Europeans, and most other populations. Besides morphological assessments, the application of Fordisc® has become a useful tool within the last two decades, creating discriminant functions from morphometric data. Unfortunately, until now, white populations are mostly represented by measurements of American individuals. Therefore, classification rates are lower for European skulls than for Euro-Americans. The aim of this study was to show differences in sexual dimorphism between German and Euro-American crania. Furthermore, their secular change from the nineteenth to the twentieth century has been investigated. Analyses have been performed on glabella subtense (GLS), mastoid height (MDH), and bizygomatic breadth (ZYB). Fordisc® 3.1 was used to study sexual dimorphism and secular change, whereas SAS® was used to perform a two-level ANOVA to test for variation in sex dimorphism. Euro-Americans show greater dimorphism than Germans in all three measurements tested. This larger difference is even increasing from the late nineteenth through the late twentieth century in terms of GLS and MDH, while it stays almost the same in the present Europeans. These results explain the unsatisfying classification rates of German and other European crania on Fordisc®. Data collection for European Fordisc® samples is in progress and should improve the current situation.

A century of trends in adult human height

Being taller is associated with enhanced longevity, and higher education and earnings. We reanalysed 1472 population-based studies, with measurement of height on more than 18.6 million participants to estimate mean height for people born between 1896 and 1996 in 200 countries. The largest gain in adult height over the past century has occurred in South Korean women and Iranian men, who became 20.2 cm (95% credible interval 17.5-22.7) and 16.5 cm (13.3-19.7) taller, respectively. In contrast, there was little change in adult height in some sub-Saharan African countries and in South Asia over the century of analysis. The tallest people over these 100 years are men born in the Netherlands in the last quarter of 20th century, whose average heights surpassed 182.5 cm, and the shortest were women born in Guatemala in 1896 (140.3 cm; 135.8-144.8). The height differential between the tallest and shortest populations was 19-20 cm a century ago, and has remained the same for women and increased for men a century later despite substantial changes in the ranking of countries.

A century of trends in adult human height

Being taller is associated with enhanced longevity, and higher education and earnings. We reanalysed 1472 population-based studies, with measurement of height on more than 18.6 million participants to estimate mean height for people born between 1896 and 1996 in 200 countries. The largest gain in adult height over the past century has occurred in South Korean women and Iranian men, who became 20.2 cm (95% credible interval 17.5-22.7) and 16.5 cm (13.3-19.7) taller, respectively. In contrast, there was little change in adult height in some sub-Saharan African countries and in South Asia over the century of analysis. The tallest people over these 100 years are men born in the Netherlands in the last quarter of 20th century, whose average heights surpassed 182.5 cm, and the shortest were women born in Guatemala in 1896 (140.3 cm; 135.8-144.8). The height differential between the tallest and shortest populations was 19-20 cm a century ago, and has remained the same for women and increased for men a century later despite substantial changes in the ranking of countries.

Secular growth trends among children in Beijing (1955-2010)

OBJECTIVES

To analyze the growth trends of children in Beijing from 1955 to 2010.

METHODS

Data for the period 1955-1975 were derived from published records. Data for the period 1985-2010 were derived from the Chinese National Survey on Students' Constitution and Health (CNSSCH). Since 1985, the overall sampling and measurement methods have been consistent. The mean, the standard deviation, and the variance (ANOVA) of height, weight, and BMI by age and sex of students aged 7-17 were calculated and analyzed.

RESULTS

Between 1955 and 2010, the average height and weight of children in Beijing has increased. The average increments per decade for boys and girls were 2.45cm and 2.03cm in height and 2.68kg and 1.68kg in weight, respectively. The largest height increase per decade occurred between 1975 and 1985: 4.51cm and 3.23cm for boys and girls, respectively. The largest height increase for the entire 55-year period under study occurred among boys at age 13 (17.85cm) and among girls at age 11 (15.90cm.)

CONCLUSIONS

During the period 1955-2010, growth trends among children in Beijing were positive. The health and nutritional status of these children improved significantly. Since 2007, might be related to government intervention, childhood obesity has been curbed.

Divergent associations of height with cardiometabolic disease and cancer: epidemiology, pathophysiology, and global implications

Among chronic non-communicable diseases, cardiometabolic diseases and cancer are the most important causes of morbidity and mortality worldwide. Although high BMI and waist circumference, as estimates of total and abdominal fat mass, are now accepted as predictors of the increasing incidence of these diseases, adult height, which also predicts mortality, has been neglected. Interestingly, increasing evidence suggests that height is associated with lower cardiometabolic risk, but higher cancer risk, associations supported by mendelian randomisation studies. Understanding the complex epidemiology, biology, and pathophysiology related to height, and its association with cardiometabolic diseases and cancer, is becoming even more important because average adult height has increased substantially in many countries during recent generations. Among the mechanisms driving the increase in height and linking height with cardiometabolic diseases and cancer are insulin and insulin-like growth factor signalling pathways. These pathways are thought to be activated by overnutrition, especially increased intake of milk, dairy products, and other animal proteins during different stages of child development. Limiting overnutrition during pregnancy, early childhood, and puberty would avoid not only obesity, but also accelerated growth in children-and thus might reduce risk of cancer in adulthood.

Adult height, nutrition, and population health

In this review, the potential causes and consequences of adult height, a measure of cumulative net nutrition, in modern populations are summarized. The mechanisms linking adult height and health are examined, with a focus on the role of potential confounders. Evidence across studies indicates that short adult height (reflecting growth retardation) in low- and middle-income countries is driven by environmental conditions, especially net nutrition during early years. Some of the associations of height with health and social outcomes potentially reflect the association between these environmental factors and such outcomes. These conditions are manifested in the substantial differences in adult height that exist between and within countries and over time. This review suggests that adult height is a useful marker of variation in cumulative net nutrition, biological deprivation, and standard of living between and within populations and should be routinely measured. Linkages between adult height and health, within and across generations, suggest that adult height may be a potential tool for monitoring health conditions and that programs focused on offspring outcomes may consider maternal height as a potentially important influence.

Change in the height of Korean children and adolescents: analysis from the Korea National Health and Nutrition Survey II and V

Purpose

The mean adult height of Koreans has increased since nationwide anthropological measurements began in 1967. The objective of this study was to evaluate differences in heights of Korean late adolescents and young adults within and between the Second and Fifth Korea National Health and Nutrition Examination Surveys (KNHANES II and V).

Methods

Koreans aged ≤22 years with available measurements of height were enrolled from the KNHANES surveys (KNHANES II: n=3,372 [1,732 males and 1,640 females]; KNHANES V: n=6,190 [3,198 males and 2,992 females]). Differences in the height of KNHANES respondents within and between surveys were evaluated according to age and sex.

Results

In KNHANES II, there was no significant difference in height between males aged 17-19 years and those aged 20-22 years (174.3±0.5 cm vs. 174.3±0.6 cm, P=0.995). Females aged 20-22 years were taller than those aged 17-19 years (159.8±0.4 cm vs. 161.0±0.4 cm, P=0.017). Females aged 17-19 years were significantly taller in KNHANES V than in KNHANES II (161.2±0.3 cm vs. 159.8±0.4 cm, P=0.004). Respondents aged 20-22 years were taller in KNHANES V than in KNHANES II, although not significantly so; the difference was 0.3±0.8 cm in males (P=0.721) and 0.5±0.6 cm in females (P=0.386).

Conclusion

Koreans appear to continue growing even in their late adolescence and early twenties. Consequently, it may be necessary to expand the reference age ranges of the Korean growth chart. Additionally, a longitudinal growth survey is needed to determine growth patterns and secular trend in height among Koreans.

Human fertility, molecular genetics, and natural selection in modern societies

Research on genetic influences on human fertility outcomes such as number of children ever born (NEB) or the age at first childbirth (AFB) has been solely based on twin and family-designs that suffer from problematic assumptions and practical limitations. The current study exploits recent advances in the field of molecular genetics by applying the genomic-relationship-matrix based restricted maximum likelihood (GREML) methods to quantify for the first time the extent to which common genetic variants influence the NEB and the AFB of women. Using data from the UK and the Netherlands (N = 6,758), results show significant additive genetic effects on both traits explaining 10% (SE = 5) of the variance in the NEB and 15% (SE = 4) in the AFB. We further find a significant negative genetic correlation between AFB and NEB in the pooled sample of –0.62 (SE = 0.27, p-value = 0.02). This finding implies that individuals with genetic predispositions for an earlier AFB had a reproductive advantage and that natural selection operated not only in historical, but also in contemporary populations. The observed postponement in the AFB across the past century in Europe contrasts with these findings, suggesting an evolutionary override by environmental effects and underscoring that evolutionary predictions in modern human societies are not straight forward. It emphasizes the necessity for an integrative research design from the fields of genetics and social sciences in order to understand and predict fertility outcomes. Finally, our results suggest that we may be able to find genetic variants associated with human fertility when conducting GWAS-meta analyses with sufficient sample size.

Secular trends in body height and body mass in 19-year-old Polish men based on six national surveys from 1965 to 2010

OBJECTIVES

The aim was to determine whether an intergenerational trend toward increased stature is slowing down, and whether body weight has recently increased among young men in Poland, as it has in Western European countries.

METHODS

Data were taken from six national surveys of 19-year-old Polish male conscripts from cohorts 1965, 1976, 1986, 1995, 2001, and 2010.

RESULTS

The mean stature of this population increased throughout the last 45 years from 170.5 cm in 1965 to 178.3 in 2010. However, the average gain in stature per decade declined from 2.4 cm in the period 1965 to 1976 to 0.8 cm per decade in 1995 to 2001, but increased to 1.0 cm in the last period. The average of body weight increased from 63.2 kg in 1965 to 73.1 in 2010 and body mass index (BMI) rose from 21.73 to 22.94 in the same period. The tempo of increase varied in different periods; between 1965 and 1986 an insignificant increase was observed (of circa 0.12); in 1986 to 1995 there was no increase, whereas the period of 2001 to 2010 witnessed a significant increase (of circa 0.76).

CONCLUSIONS

The trend of body size and stature increase within the Polish population, although decelerating, remained positive and steady during the last 45 years. No significant impact of the past half-century's socioeconomic crises was observed in these measures of growth. We concluded that during the economic crises some effective mechanism protecting the living conditions of the children and youth were operating within the population.

[Prevalence of allergic diseases in Germany: results of the German Health Interview and Examination Survey for Adults (DEGS1)]

In the first wave of the "German Health Interview and Examination Survey for Adults" (DEGS1), up-to-date and representative data regarding allergic diseases of 7988 18- to 79-year-old subjects living in Germany were collected using computer-assisted medical interviews. The study identified a lifetime prevalence of 8.6% for asthma, 14.8% for allergic rhinoconjunctivitis, 3.5% each for atopic dermatitis and urticaria, 8.1% for contact eczema, 4.7% for food allergies and 2.8% for insect venom allergies. Overall, nearly one third of adults in Germany have been diagnosed with at least one of the above mentioned allergies during their lifetime by a physician. Currently, nearly 20% suffer from at least one allergic disease. Generally, women reported an allergic disease more frequently than men and younger subjects more frequently than older ones. Additionally, allergies are more common in the former federal states of West Germany than in the former East German federal states. A high socioeconomic status and living in large cities both increase allergy risk. During the last 10 years, asthma prevalence increased about 3%, whereas the prevalence of urticaria and contact eczema declined. The lifetime prevalence of allergic rhinoconjunctivitis, atopic dermatitis and food allergies appeared unchanged. In total, allergy prevalence has declined from 32.7-28.7% over the past decade. An English full-text version of this article is available at SpringerLink as supplemental.

Fetal and maternal genes' influence on gestational age in a quantitative genetic analysis of 244,000 Swedish births

Although there is increasing evidence that genetic factors influence gestational age, it is unclear to what extent this is due to fetal and/or maternal genes. In this study, we apply a novel analytical model to estimate genetic and environmental contributions to pregnancy history records obtained from 165,952 Swedish families consisting of offspring of twins, full siblings, and half-siblings (1987-2008). Results indicated that fetal genetic factors explained 13.1% (95% confidence interval (CI): 6.8, 19.4) of the variation in gestational age at delivery, while maternal genetic factors accounted for 20.6% (95% CI: 18.1, 23.2). The largest contribution to differences in the timing of birth were environmental factors, of which 10.1% (95% CI: 7.0, 13.2) was due to factors shared by births of the same mother, and 56.2% (95% CI: 53.0, 59.4) was pregnancy specific. Similar models fit to the same data dichotomized at clinically meaningful thresholds (e.g., preterm birth) resulted in less stable parameter estimates, but the collective results supported a model of homogeneous genetic and environmental effects across the range of gestational age. Since environmental factors explained most differences in the timing of birth, genetic studies may benefit from understanding the specific effect of fetal and maternal genes in the context of these yet-unidentified factors.

Intergenerational influences on child growth and undernutrition

Intergenerational effects on linear growth are well documented. Several generations are necessary in animal models to 'wash out' effects of undernutrition, consistent with the unfolding of the secular trend in height in Europe and North America. Birthweight is correlated across generations and short maternal stature, which reflects intrauterine and infant growth failure, is associated with low birthweight, child stunting, delivery complications and increased child mortality, even after adjusting for socio-economic status. A nutrition intervention in Guatemala reduced childhood stunting; it also improved growth of the next generation, but only in the offspring of girls. Possible mechanisms explaining intergenerational effects on linear growth are not mutually exclusive and include, among others, shared genetic characteristics, epigenetic effects, programming of metabolic changes, and the mechanics of a reduced space for the fetus to grow. There are also socio-cultural factors at play that are important such as the intergenerational transmission of poverty and the fear of birthing a large baby, which leads to 'eating down' during pregnancy. It is not clear whether there is an upper limit for impact on intrauterine and infant linear growth that programmes in developing countries could achieve that is set by early childhood malnutrition in the mother. Substantial improvements in linear growth can be achieved through adoption and migration, and in a few selected countries, following rapid economic and social development. It would seem, despite clear documentation of intergenerational effects, that nearly normal lengths can be achieved in children born to mothers who were malnourished in childhood when profound improvements in health, nutrition and the environment take place before conception. To achieve similar levels of impact through public health programmes alone in poor countries is highly unlikely. The reality in poor countries limits the scope, quality and coverage of programmes that can be implemented and modest impact should be expected instead. The Lancet series on Maternal and Child Undernutrition estimated that implementation to scale of proven interventions in high burden countries would reduce stunting by one-third; this is perhaps a realistic upper bound for impact for high quality programmes, unless accompanied by sweeping improvements in social services and marked reductions in poverty. Finally, because so much can be achieved in a single generation, intergenerational influences are unlikely to be an important explanation for lack of programme impact aimed at the window of the first 1000 days. Failure to prevent linear growth failure in developing countries has serious consequences for short- and long-term health as well as for the formation of human capital. The nutrition transition has created a double burden by adding obesity and related chronic diseases to the public health agenda of countries still struggling with the 'old' problems of maternal and child undernutrition. The challenge ahead is to increase efforts to prevent linear growth failure while keeping child overweight at bay.