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. Thus, prediction of the timing of a maturational spurt is often desirable in order to determine the likelihood that a child will catch up to their chronological age peers. Serial data from the Fels Longitudinal Study were used to predict future skeletal age conditional on current skeletal age and to predict the timing of maturational spurts. For children who were delayed relative to their chronological age peers, the likelihood of catch‐up maturation increased through the average age of onset of puberty and decreased prior to the average age of peak height velocity. For boys, the probability of an imminent maturational spurt was higher for those who were less mature. For girls aged 11 to 13 years, however, this probability was higher for those who were more mature, potentially indicating the presence of a skeletal maturation plateau between multiple spurts. The prediction model, available on the web, is most relevant to children of European ancestry living in the Midwestern US. Our model may also provide insight into the tempo of maturation for children in other populations, but must be applied with caution if those populations are known to have high burdens of environmental stressors not typical of the Midwestern US. Am J Phys Anthropol, 2013. © 2012 Wiley Periodicals, Inc.     

Fatness and skeletal maturity of Belgian boys 12 through 17 years of age

Relationships between fatness and skeletal maturity are considered in a nationwide sample of 14,259 Belgian boys 12 through 17 years of age (The Leuven Growth Study of Belgian Boys). Absolute fatness was estimated from four skinfolds using the Drinkwater and Ross technique and from the sum of four skinfolds, and was related to skeletal maturity assessed by the Tanner-Whitehouse method (I and II). In addition, comparisons were made between the fattest 5% and leanest 5% of the boys at each age level. Correlations between the indices of fatness and skeletal age and relative skeletal age (the difference between skeletal and chronological ages) are positive and generally low, ranging from 0.12 to 0.39. They tend to decrease with age from 12 to 17 years. Comparisons between the extreme groups indicate that the leanest boys are more delayed in skeletal maturity, by about 0.8 years, than the fattest boys are advanced, by about 0.5 years. Stature data for the same boys are consistent with the skeletal maturity data and thus suggest that the size differences between the extreme groups are due in part to maturity differences. Over the age span 12 through 20 years, the leanest boys are reduced in stature by about – 1.2 standard deviations, while the fattest boys are larger in stature by about +0.6 standard deviation units. The size differences, however, persist after skeletal maturity is attained so that there may be a specific role for fatness in influencing statural growth.     

Estimation of stature in children from second metacarpal measurements.

On the basis of 552 boys and 542 girls aged 6 to 20 years, this study examines the estimation of stature from dimensions and maturity of second metacarpals by means of linear regression equations. A combination of length and width measurements provided a more accurate estimation than each measurement individually. When taken alone, length produced a more accurate estimation than width. Sex and age factors are useful for the estimation of stature, though these variables are often unknown in the isolated bone. The samples are divided into immature and mature groups (according to skeletal maturity). Regardless of sex, stature could be estimated from the metacarpal length and width with a standard error of 4.19 cm by means of a multiple linear equation in the immature group. The mature group should be considered with adults for this purpose. Thus, taking into account their skeletal maturity, living stature could be practically estimated from the second metacarpal with significant degrees of accuracy in children.     

Caloric restriction optimizes the proteasome pathway with aging in rat plantaris muscle: implications for sarcopenia

To gain insight into the significance of alterations in the proteasome pathway for sarcopenia and its attenuation by calorie restriction, we examined protein oxidation and components of the proteasome pathway in plantaris muscle in 8-, 30-, and 35-mo-old ad libitum-fed (AL) rats; and in 8-, 35-, and 40-mo-old calorie-restricted (CR) rats. We hypothesized that CR rats would exhibit a lesser accumulation of protein carbonyls with aging and that this would be associated with a better maintenance of skeletal muscle proteasome activity and function with aging. Consistent with this view, whereas AL rats had a significant increase in protein carbonylation with aging, there was no such increase in CR rats. Protein levels of the ubiquitin ligases MuRF1 and MAFbx increased similarly with aging in both AL and CR rats. On the other hand, chymotrypsin-like activity of the proteasome increased with aging more gradually in CR rats, and this increase was paralleled by increases in the expression of the C2 subunit in both groups, suggesting that differences in activity were not related to differences in proteasome function with aging. Interestingly, the plot of muscle mass vs. proteasome activity showed that the oldest animals in both diets had a lower muscle mass than would be predicted by their proteasome activity, suggesting that other factors explain the acceleration of sarcopenia at advanced age. Since calorie restriction better protects skeletal muscle function than muscle mass with aging (Hepple RT, Baker DJ, Kaczor JJ, Krause DJ, FASEB J 19: 1320-1322, 2005), and our current results show that this protection of function is associated with a prevention of oxidative protein damage accumulation, we suggest that calorie restriction optimizes the proteasome pathway to preserve skeletal muscle function at the expense of modest muscle atrophy.     

A craniofacial growth maturity gradient for males and females between 4 and 16 years of age

Differential growth of the craniofacial complex implies variation in ontogenetic patterns of development. This investigation quantifies the relative maturity—as defined by percent adult status—of nine cephalometric dimensions and stature. Analysis is based on 663 lateral cephalograms from a mixed longitudinal sample of 26 males and 25 females between 4 and 16 years of age. Graphic comparison of maturity status across the age range shows that variation is intergraded between the neural and somatic growth maturity patterns, as described by head height and stature, respectively. The maturity gradient moves from head height through anterior cranial base, posterior cranial base and maxillary length, upper facial height, corpus length, and ramus height to stature. After 9 years of age ramus height is less mature than stature. Anterior maxillary and mandibular heights diminish during transitional dentition and thereafter exhibit maturity patterns that compare to corpus length. Although females are consistently more mature than males, the gradient of variation between dimensions is sex independent.     

The influence of body size on adult skeletal age estimation methods

Accurate age estimations are essential to archaeological and forensic analyses. However, reliability for adult skeletal age estimations is poor, especially for individuals over the age of 40 years. This is the first study to show that body size influences skeletal age estimation. The ??can et al., Lovejoy et al., Buckberry and Chamberlain, and Suchey‐Brooks age methods were tested on 764 adult skeletons from the Hamann‐Todd and William Bass Collections. Statures ranged from 1.30 to 1.93 m and body masses ranged from 24.0 to 99.8 kg. Transition analysis was used to evaluate the differences in the age estimations. For all four methods, the smallest individuals have the lowest ages at transition and the largest individuals have the highest ages at transition. Short and light individuals are consistently underaged, while tall and heavy individuals are consistently overaged. When femoral length and femoral head diameter are compared with the log‐age model, results show the same trend as the known stature and body mass measurements. The skeletal remains of underweight individuals have fewer age markers while those of obese individuals have increased surface degeneration and osteophytic lipping. Tissue type and mechanical loading have been shown to affect bone turnover rates, and may explain the differing patterns of skeletal aging. From an archaeological perspective, the underaging of light, short individuals suggests the need to revisit the current research consensus on the young mortality rates of past populations. From a forensic perspective, understanding the influence of body size will impact efforts to identify victims of mass disasters, genocides, and homicides. Am J Phys Anthropol 156:35–57, 2015 © 2014 Wiley Periodicals, Inc.     

Anatomical, physiological, and epidemiological correlates of the aging process: a confirmation of multifactorial age determination in the Libben skeletal population

Paleodemographic analyses based on estimates of skeletal age at death consistently report high levels of young adult mortality with few individuals living in excess of 50 years. Critics assert these data indicate systematic underaging of adults and justifiably remark that criteria for estimating skeletal age at death may be unreliable, age determinations are too frequently based on one or two criteria alone, and adult paleodemographic age profiles often mimic the age distribution of the modern population from which an age indicator's standards were originally derived. This study reports a series of tests based on well-documented biological aging phenomena that can be used to investigate potential effects of systematic underaging in adults, assuming the skeletal population is of sufficient size to permit such tests. These include patterns of third decade sternal clavicular epiphyseal fusion, multiple age and sex criteria associated with cortical bone dynamics, and fractures known to occur throughout the entire adult ages range. These phenomena are examined here for the Libben site skeletal population where adult age at death was determined by the multifactorial summary age technique. None of the biological criteria reported here were used in the Libben summary age analysis and thus serve as an independent test of accuracy in age determination. In addition, the summary age method has recently been applied to a series of modern skeletons of known age (Todd samples 1 and 2). Age standards for criteria employed with Libben and Todd 1 were identical. Since Todd 1 displayed underaging in older adults, a second Libben age distribution adjusted for Todd 1 bias was generated for comparison. A third Libben adult survivorship profile based on a Coale and Demeny West level 3 mortality experience, considered by some to be a more realistic model for skeletal populations, was produced for comparison. For all criteria examined, original Libben summary ages provided superior concordance with known patterns of biological aging in human populations. While Libben ages adjusted for Todd 1 bias were slightly better in the third decade, both Todd 1 adjusted and Coale and Demeny West level 3 age distributions produced unrealistic patterns of biological aging for individuals greater than 35 years. Implications of these results are discussed.     

The body build and composition of Samoan children: Relationships to infant feeding patterns and infant weight-for-length status

The relationships between infant feeding patterns, infant weight status, and subsequent growth are not yet firmly established. This study attempts to address these topics among Samoan children. The study population consists of 1,186 children born between October 1974 and September 1976 who were subsequently seen in the Well Baby Clinic in American Samoa. On the basis of the clinic records the children were categorized into feeding groups (breast vs. bottle) and weight-for-length groups (<25th percentile or >75th percentile of National Center for Health Statistics (NCHS) standards). A survey of 74 of these children was conducted in 1982. The average age of the children was 6.6 years. Twenty anthropometric measurements were taken and divided into three groups: skeletal, adipose, and mixed. Multiple analysis of variance was used on each of the groups of measurements to assess effects of infant feeding and weight-for-length. This analysis demonstrated significant relationships between infant weight-for-length and childhood skeletal size (heavy infants are larger children); between infant feeding patterns and childhood adiposity (bottle-fed children are fatter); and between both infant patterns and the mixed measurements (heavy and bottle-fed infants are heavier children with larger circumferences). The relationship between infant weight-for-length and skeletal size may be a continuation of infant patterns of high musculoskeletal weight in heavy infants. The relationship between infant feeding and childhood fatness was not affected by family income.     

Nutritional stress and growth: sex difference in adaptive response

Most of the residents of Heliconia, Colombia, live in a continual state of malnutrition characterized by a lack of protein and an excess of carbohydrate in the diet. Kwashiorkor and Marasmus are frequently observed when such dietary imbalances occur. These conditions are seen in Heliconia, but even when the recognized symptoms of clinical malnutrition are absent, there are long-term morphological changes associated with protein deficiency. In the present study, interest is centered on the relative effects of protein deficiency on the skeletal maturation of apparently healthy boys and girls. Incidental comparisons of clinically-diagnosed Kwashiorkor and Marasmus patients with each other and with non-affected controls are also made. It is seen that skeletal maturation in early life is delayed in almost all Heliconia children when compared to U.S. standards. Female controls appear to experience a form of catch-up growth beginning in the preadolescent period, while male controls appear more severely retarded throughout adolescence. The result is a reduction in stature most pronounced in boys and a concomitant reduction in sexual dimorphism for overall body size. The Kwashiorkor- and Marasmus-affected children show a more severe retardation of skeletal growth with no significant sex difference in their response.     

Cross-sectional growth of pastoralist Karimojong and Turkana children

In this study, we compare cross-sectional growth in two Nilotic pastoralist populations, the Turkana and Karimojong of northern East Africa. Until the middle of the 18th century, these two groups constituted one population, and their genetic affinities consequently are assumed to be strong. Known differences in their subsistence practices as well as their recent cultural history allow us to consider the genetic vs. environmental determinants of their growth patterns. Growth in stature of the two groups is remarkably similar, whereas the pattern of ponderal growth varies, particularly in infancy and adolescence. Both groups demonstrate the linear adult physique that is characteristic of savanna-dwelling peoples in East Africa, but the Karimojong are heavier and fatter after early childhood. Linearity of physique is related to narrow skeletal breadth, a trait that emerges early in childhood among the Karimojong and is strongly correlated with weight: this finding supports the climatic hypothesis of human body shape and size. Extreme leanness, determined from body mass index, is correlated with fat stores, which are only weakly correlated with weight, height, or skeletal breadth. Linearity of physique appears to have a substantial genetic component, whereas fatness is hypothesized to relate to differences in subsistence strategies and exposure to environmental and cultural stress.     

Preferences Predict Food Intake From 5 to 11 Years,but Not in Girls With Higher Weight Concerns,Dietary Restraint,and %Body Fat

Food preferences (FP) predict food intake in childhood; however, the predictive power of FP may decline among girls as weight concerns (WC) and dietary restraint (DR) increase during preadolescence. To examine longitudinal change in the preference‐intake (P‐I) relation and assess whether this relation weakens among non‐Hispanic white girls (n = 197) with a history of WC and DR from age 5 to 11. Girls' preferences for and intake (kcal) of 10 palatable snack foods were assessed biennially. Height, weight, percent body fat (%BF), WC, and DR were measured. Individual correlation coefficients were calculated per girl to capture within‐person P‐I correlations at each time of measurement. Overall, FP predicted girls' snack food calorie intakes between 5 and 11 years, but latent profile analysis (LPA) revealed three distinct patterns of change in P‐I correlations over time: “strong/stable” P‐I correlations were relatively high and became stronger with age; “increasing/later null” P‐I correlations were initially weak and became stronger between 5 and 9 years, but dropped to near 0 at 11 years; “initially weak/later strong” P‐I correlations were initially null and increased with age. Mixed models revealed that the “increasing/later null” group had greater increases in %BF, and higher WC, DR, and BMI percentiles from 5 to 11 years, compared to the other groups. In summary, FP predicted snack food calorie intake among most girls during childhood, but waned as a predictor of calorie intake at age 11 for a subset of girls with increasing %BF, and higher WC, DR, and BMIs.     

Evolutionary trends of stature in upper Paleolithic and Mesolithic Europe

Long bone lengths of all available European Upper Paleolithic (41 males, 25 females) and Mesolithic (171 males, 118 females) remains have been transformed into stature estimates by means of new regression equations derived from Early Holocene skeletal samples using "Fully's anatomical stature" and the major axis regression technique (Formicola & Franceschi, 1996). Statistical analysis of the data, with reference both to time and space parameters, indicates that: (1) Early Upper Paleolithic samples (pre-Glacial Maximum) are very tall; (2) Late Upper Paleolithic groups (post-Glacial Maximum) from Western Europe, compared to their ancestors, show a marked decrease in height; (3) a further, although not significant, reduction of stature affects Western Mesolithics; (4) no regional differences have been observed during both phases of the Upper Paleolithic; (5) a high level of homogeneity has also been found in the Mesolithic, both in Western and Eastern Europe; (6) the internal homogeneity found during the Mesolithic in Western and Eastern Europe is associated with marked inter-regional variability, with populations of the latter region showing systematically significantly greater stature than their Western contemporaries. Evaluation of possible causes for the great stature of the Early Upper Paleolithic samples points to high nutritional standards as the most important factor. Results obtained on later groups clearly indicate that the Last Glacial Maximum, rather than the Mesolithic transition, is the critical phase in the negative trend affecting Western European populations. While changes in the quality of the diet, and in particular decreased protein intake, provide a likely explanation for that trend, variations in levels of gene flow probably also played a role. Reasons for the West-East Mesolithic dichotomy remain unclear and lack of information for the Late Upper Paleolithic of Eastern Europe prevents insight into the remote origins of this phenomenon. Analysis of regional differentiation of stature, particularly well supported by data from Mesolithic sites, points to the absence of today's latitudinal gradients and suggests a relative homogeneity in dietary, cultural and biodemographic patterns for the last hunter-gatherer populations of Western Europe.     

Stature estimation in prehistoric Native Americans of Ohio

In the present report we investigate stature estimation techniques in a sample of 64 (35 male, 29 female) prehistoric Native Americans from Ohio. Because living stature is unknown for these 64 individuals, we use Fully's (1956) anatomical method to provide the best estimates of living stature. In this method all osseous components of skeletal height are measured and soft tissue correction is added. Comparisons of regression equations commonly used for stature estimation in prehistoric Eastern Woodland Native American populations, but developed for East Asian and East Asian-derived populations (using lower extremity components), show that these commonly used equations consistently yield stature estimates 2 to 8 cm in excess of the best estimates from Fully's method. Based on the skeletal height measures of the 64 individuals in the present sample, we develop regression equations for the estimation of stature. These equations yield stature estimates virtually identical to estimates from Fully's method and may prove useful for stature reconstruction in other prehistoric Eastern Woodland Native American populations.     

Epiphyseal union at the innominate and lower limb in a modern Portuguese skeletal sample, and age estimation in adolescent and young adult male and female skeletons

This study documents the timing of epiphyseal union at the innominate, femur, tibia, and fibula in a sample of modern Portuguese skeletons. The sample was taken from the Lisbon documented skeletal collection and it is comprised of 57 females and 49 males between the ages of 9 and 25. Individuals are mostly representative of the middle-to-low socioeconomic segment of the early 20th century Lisbon population. A total of 18 anatomical locations were examined for epiphyseal union using a three-stage scheme: 1) no union; 2) partial union; and 3) completed union, all traces of fusion having disappeared. Results show that females are ahead of males by 1-2 years and provide similar age ranges for the stages of union than previous studies. Some variations between studies can be explained by methodological differences between dry bone and radiographic observations. However, a review of the literature indicates that socioeconomic status of a given population seems to be of decisive importance to the rate of ossification and most of the differences in skeletal maturation across studies and populations can probably be ascribed to different levels of social and economic development of the societies in which the individuals lived. Although the effects of socioeconomic status in skeletal maturation are greater during childhood than in adolescence, as to make the timing of epiphyseal union a reliable estimate of age at death, they are not negligible and age estimates should take into account the likely socioeconomic status of the individual, whose remains are under examination.     

Developmental stage‐dependent influence of environmental factors on growth of rural Sundanese children in West Java,Indonesia

This study investigated the growth trajectories and the relative relevance levels of nutrition, disease, and hormonal status at various developmental stages among children in adverse environments to provide population‐based empirical evidence for the life history theory. Three years of longitudinal anthropometric data in 1‐year intervals were obtained from 418 boys and girls aged 0 to 12 years at recruitment. Following the final measurement, the main survey, which included blood and feces sampling, 3‐h interval food consumption recall surveys for energy and nutrient intakes and anthropometry, was performed. Blood and feces were used for detecting, respectively, anemia and hormonal (IGF‐I and IGFBP‐3) levels as well as intestinal helminthiasis (Ascaris, Trichuris, and hookworm). The major findings of this study are summarized as follows: 1) the growth velocity of the subject children lagged behind international standards during childhood and juvenility but caught up during early adolescence; 2) diseases, both intestinal helminths and anemia, had significant effects on growth in childhood but not at older ages; and 3) hormonal status significantly affected growth in the children, with its highest significance in early adolescence. A larger growth than international standards in early adolescence likely follows programmed hormonal mechanisms after the onset of puberty. The onset of puberty might be associated with adequate amounts of nutrient intake and be mediated by hormonal function, because the IGF‐IZ score was significantly correlated with energy and protein intakes at the transitional period from juvenility to adolescence, when puberty occurs. Am J Phys Anthropol 157:94–106, 2015. © 2015 Wiley Periodicals, Inc.     

Biracial study of arterial pressures in the first and second decades of life.

The blood pressures of young Black and White American schoolchildren were measured and compared with those of Nigerian children of similar ages. Both diastolic and systolic pressures were consistently higher in the Nigerian children than in the Americans, both Black and White. The White children had the lowest pressures at each age. The mean weights and heights at each age were not significantly different in the three groups. Although the blood pressure of African children was higher than that of Black Americans, mean adult pressures are known to be similar in both groups. This suggests that the difference in childhood pressures must be due more to environmental factors than to genetic ones.     

Greater sciatic notch morphology: sex, age, and population differences

The accuracy of a method for visually scoring sex differences in the greater sciatic notch was tested on 296 skeletons of known age and sex. The proportion of correct sex assignments is 80% when all specimens are classified, and 89% when os coxae assigned the score in which the sexes show the greatest overlap are excluded. Although many os coxae (35%) have this sexually intermediate morphology, excluding them has the advantage of substantially reducing sex biases in sexing errors. For both sexes, there is a strong relationship between age at death and sciatic notch score. People who die at a younger age tend to have wider, more feminine-appearing sciatic notches than people of greater longevity. There are also significant population differences. The 18th-19th century English sample from St. Bride's Church has a more feminine morphology than Americans of European or African ancestry. Environmental influences on skeletal development (vitamin D deficiency) appear to provide the most likely explanation for these population differences.     

Synthetic standards for body weight

Growth charts represent body stature, body weight, and body mass index (BMI) from birth to maturity. Due to secular changes in these parameters, growth charts tend to become outdated, and must be revised from time to time. Recently, we developed alternative strategies that facilitate developing and renewing growth charts, and suggested synthetic standards for body stature. The increasing prevalence of obesity has made it necessary to develop similar techniques also for monitoring body weight and BMI. Two-hundred-and-forty historic and modern growth studies (108 studies of male growth, 132 studies of female growth) were selected from 22 European, 6 American, 3 African, and 6 Asian nations, published between 1831 and 2001. The studies contained annual information on weight and stature, either between birth and 6 years, or between 6 years and maturity, or information on the whole age range between birth and maturity. Since historic studies up to the mid-20th century usually ignore the fact that body weight (in contrast to body stature) is not normally distributed, a group of 92 more recent studies (45 male, 47 female), published between 1943 and 2001, presenting centiles for weight, was chosen for additional analysis. Furthermore, the skewness of body weight distributions, was investigated in original raw data of body weight obtained from five well reputed longitudinal growth studies, performed at Jena, Germany, Lublin, Poland, Paris, France, Prague, Czech Republic, and Zürich, Switzerland. Average body stature and average weight differ markedly between different populations. But within the same population, both parameters are closely interrelated. In males, birth length and weight correlated with r = 0.503, stature and weight correlated with r = 0.873 at the age of 2 years; with r = 0.882 at the age of 6 years; with r = 0.935 at the age of 14 years, and with r = 0.891 at the age of 18 years. Similar results were obtained in females. At birth, length and weight correlated with r = 0.619. Stature and weight correlated with r = 0.863 at the age of 2; with r = 0.912 at the age of 6; with r = 0.935 at the age of 12; and with r = 0.918 at the age of 15 years. Tables of linear regression coefficients for relative stature and weight at all ages enable the reversal of the process of the meta-analysis and allow the generation of synthetic growth references for stature and weight. Synthetic reference charts help in the revision of current growth charts without much additional effort, and may be used for populations for which autochthonous growth standards are not available.