The satisfactory growth and development at 2 years of age of the INTERGROWTH-21 Fetal Growth Standards cohort support its appropriateness for constructing international standards.

Background: The World Health Organization recommends that human growth should be monitored with the use of international standards. However, in obstetric practice, we continue to monitor fetal growth using numerous local charts or equations that are based on different populations for each body structure. Consistent with World Health Organization recommendations, the INTERGROWTH-21 Project has produced the first set of international standards to date pregnancies; to monitor fetal growth, estimated fetal weight, Doppler measures, and brain structures; to measure uterine growth, maternal nutrition, newborn infant size, and body composition; and to assess the postnatal growth of preterm babies.

Precision of recumbent crown-heel length when using an infantometer.

Background: Crown-heel length (CHL) measurement is influenced by technique, training, experience and subject cooperation. We investigated whether extending one or both of an infant's legs affects the precision of CHL taken using an infantometer. The influence of staff training and infant cooperation were also examined.

Relationships Between Age at Menarche, Walking Gait Base of Support, and Stance Phase Frontal Plane Knee Biomechanics in Adolescent Girls.

Background: Age at menarche impacts patterns of pubertal growth and skeletal development. These effects may carry over into variation in biomechanical profiles involved in sports-related traumatic and overuse knee injuries. The present study investigated whether age at menarche is a potential indicator of knee injury risk through its influence on knee biomechanics during normal walking.

Reading, Mathematics and Fine Motor Skills at 5 Years of Age in US Children who were Extremely Premature at Birth.

Objectives The prevalence of extreme prematurity at birth has increased, but little research has examined its impact on developmental outcomes in large representative samples within the United States. This study examined the association of extreme prematurity with kindergarteners' reading skills, mathematics skills and fine motor skills. Methods The early childhood longitudinal study-birth cohort, a representative sample of the US children born in 2001 was analyzed for this study.

Sex differences in the rate of abdominal adipose accrual during adulthood: the Fels Longitudinal Study.

Objectives: The purpose of this analysis was to evaluate sex differences in the rate of visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) accrual in adults. Secondary analyses examined differences in the rate of VAT and SAT accrual in premenopausal, perimenopausal and postmenopausal women.

Subjects/methods: Participants were 472 (60% female) non-Hispanic whites and aged 18-84 years at baseline in whom abdominal VAT and SAT were assessed using multiple-image magnetic resonance imaging at two time points, with an average follow-up of 7.

The ontogeny of nasal shape: An analysis of sexual dimorphism in a longitudinal sample.

Objectives: Potential integration between the nasal region and noncranial components of the respiratory system has significant implications for understanding determinants of craniofacial variation. There is increasing evidence that sexual dimorphism in body size and associated male-female differences in energetically relevant variables influence the development of the nasal region. To better understand this relationship, we examined the ontogeny of sexual dimorphism in nasal shape using a longitudinal series of lateral cephalograms.

Is infant body mass index associated with adulthood body composition trajectories? An exploratory analysis.

Background: Infant body mass index (BMI) is increasingly used as a marker of obesity risk based on its association with young-adulthood BMI.

Objectives: The aim of this study is to test the association of infant BMI with young-adulthood fat mass and fat-free mass, and how this association changes during advancing adulthood.

Methods: Body mass index Z-score at age 9 months was measured in 350 White, non-Hispanic Fels Longitudinal Study participants.

"Time for dabs": Analyzing Twitter data on marijuana concentrates across the U.S.

Aims: Media reports suggest increasing popularity of marijuana concentrates ("dabs"; "earwax"; "budder"; "shatter; "butane hash oil") that are typically vaporized and inhaled via a bong, vaporizer or electronic cigarette. However, data on the epidemiology of marijuana concentrate use remain limited. This study aims to explore Twitter data on marijuana concentrate use in the U.

Quantitative physical activity assessment of children and adolescents in a rural population from Eastern Nepal.

Objectives: We report cross-sectional, objectively measured physical activity data for 399 children and adolescents aged 6 to 18 years. We evaluated physical activity of children and adolescents, considered time spent in each activity intensity category, and explored the impact of growth disruption (stunting and wasting) on physical activity patterns.

Methods: Participants wore an Actical (Mini-Mitter, Bend, OR) omnidirectional accelerometer for one week as part of their annual visit to the Jiri Growth Study.

Heritability of the Human Craniofacial Complex.

Quantifying normal variation and the genetic underpinnings of anatomical structures is one of the main goals of modern morphological studies. However, the extent of genetic contributions to normal variation in craniofacial morphology in humans is still unclear. The current study addresses this gap by investigating the genetic underpinnings of normal craniofacial morphology.

1α, 25-Dihydroxyvitamin D₃ and the vitamin D receptor regulates ΔNp63α levels and keratinocyte proliferation.

1α, 25-dihydroxyvitamin D3 (VD3), a secosteriod that has been explored as an anti-cancer agent, was also shown to promote cell survival. Its receptor, the Vitamin D Receptor (VDR), is a direct target of the proto-oncogene ΔNp63α, which is overexpressed in non-melanoma skin cancers. The interconnection between VDR/VD3 signaling and ΔNp63α, led us to examine whether VDR/VD3 signaling promotes keratinocyte proliferation by regulating ΔNp63α levels.

How much do children's body mass indices change over intervals of 6-12 months? Statistics from before and during the obesity epidemic.

Background: Researchers need to evaluate changes in children's body mass index (BMI) over periods of 6 or 12 months, yet reference statistics are limited for change in BMI.

Objectives: We aim to estimate the distribution of changes in children's BMIs over periods of 6 and 12 months.

Methods: We analyze data on two cohorts of children in the Fels Longitudinal Study: an older cohort born 1946-1970 and a recent cohort born 1971-1995.

Endocrine disruptive compounds and cardio-metabolic risk factors in children.

The endocrine disrupting chemicals (EDC) are exogenous chemicals that can disrupt hormonal signaling system. EDCs are ubiquitous in our environment and many EDC are detectable in humans. With the increasing obesity prevalence in children it is imperative to explore the role of EDC as obesogens.

International standards for newborn weight, length, and head circumference by gestational age and sex: the Newborn Cross-Sectional Study of the INTERGROWTH-21st Project.

Background: In 2006, WHO published international growth standards for children younger than 5 years, which are now accepted worldwide. In the INTERGROWTH-21(st) Project, our aim was to complement them by developing international standards for fetuses, newborn infants, and the postnatal growth period of preterm infants.

Methods: INTERGROWTH-21(st) is a population-based project that assessed fetal growth and newborn size in eight geographically defined urban populations.

Variation in timing, duration, intensity, and direction of adolescent growth in the mandible, maxilla, and cranial base: the Fels longitudinal study.

There is considerable individual variation in the timing, duration, and intensity of growth that occurs in the craniofacial complex during childhood and adolescence. The purpose of this article is to describe the extent of this variation between traits and between individuals within the Fels Longitudinal Study (FLS). Polynomial multilevel models were used to estimate the ages of onset, peak velocity, and cessation of adolescent growth, the time between these ages, the amount of growth between these ages, and peak velocity.

Latent class analysis of non-opioid dependent illegal pharmaceutical opioid users in Ohio.

Background: Increases in non-medical use of pharmaceutical opioids in the U.S. have resulted in increases in opioid dependence and unintentional overdose deaths.

An update of the statistical methods underlying the FELS method of skeletal maturity assessment.

Background: Evaluation of skeletal maturity provides clinicians and researchers a window into the developmental progress of the skeleton. The FELS method for maturity assessment provides a point estimate and standard error based on 98 skeletal indicators.

Aim: This paper outlines the statistical methodology used by the original FELS method and evaluates improvements that address the following: serial correlation in the calibration sample is now considered, a Bayesian estimation method is now employed to improve estimation near ages 0 and 18 years and uncertainty in the calibration due to sampling is now accounted for when computing confidence limits.

Gene-by-age effects on BMI from birth to adulthood: the Fels Longitudinal Study.

Objectives: Genome wide association studies have shown 32 loci to influence BMI in European-American adults but replication in other studies is inconsistent and may be attributed to gene-by-age effects. The aims of this study were to determine if the influence of the summed risk score of these 32 loci (GRS) on BMI differed across age from birth to 40 years, and to determine if additive genetic effects other than those in the GRS differed by age.

Methods: Serial measures of BMI were calculated at 0, 1, 3, 6, 9, 12, 18, and 28 months, and 4, 7, 11, 15, 19, 23, 30, and 40 years for 1,176 (605 females, 571 males) European-American participants in the Fels Longitudinal Study.

Predicting the timing of maturational spurts in skeletal age.

Measures of maturity provide windows into the timing and tempo of childhood growth and maturation. Delayed maturation in a single child, or systemically in a population, can result from either genetic or environmental factors. In terms of the skeleton, delayed maturation may result in short stature or indicate another underlying issue.

Skeletal growth and the changing genetic landscape during childhood and adulthood.

Growth, development, and decline of the human skeleton are of central importance to physical anthropology. All processes of skeletal growth (longitudinal growth as well as gains and losses of bone mass) are subjected to environmental and genetic influences. These influences, and their relative contributions to the phenotype, can be asserted at any stage of life.

Age-related changes in spatiotemporal characteristics of gait accompany ongoing lower limb linear growth in late childhood and early adolescence.

Walking gait is generally held to reach maturity, including walking at adult-like velocities, by 7-8 years of age. Lower limb length, however, is a major determinant of gait, and continues to increase until 13-15 years of age. This study used a sample from the Fels Longitudinal Study (ages 8-30 years) to test the hypothesis that walking with adult-like velocity on immature lower limbs results in the retention of immature gait characteristics during late childhood and early adolescence.

Associations between trunk, leg and total body adiposity with arterial stiffness.

Background: Obesity and arterial stiffness are associated, but fat distribution patterns may be more strongly related to arterial stiffness than general obesity because of the possible increased inflammation associated with increased abdominal adiposity. The aims of this study were to examine whether fat patterning is associated with arterial stiffness, and determine whether these associations are mediated by low-grade inflammation.

Methods: Adult participants from the Fels Longitudinal Study (228 males and 254 females) were assessed for brachial-ankle pulse wave velocity (BaPWV) to determine arterial stiffness.

The influence of age at menarche on cross-sectional geometry of bone in young adulthood.

Elucidating the somatic and maturational influences on the biomechanical properties of bone in children is crucial for a proper understanding of bone strength and quality in childhood and later life, and has significant potential for predicting adult fracture and osteoporosis risks. The ability of a long bone to resist bending and torsion is primarily a function of its cross-sectional geometric properties, and is negatively impacted by smaller external bone diameter. In pubescent girls, elevated levels of estrogen impede subperiosteal bone growth and increase endosteal bone deposition, resulting in bones averaging a smaller external and internal diameter relative to boys.