Birth month associations with height,head circumference,and limb lengths among peruvian children

Associations between season of birth and body size, morbidity, and mortality have been widely documented, but it is unclear whether different parts of the body are differentially sensitive, and if such effects persist through childhood. This may be relevant to understanding the relationship between early life environment and body size and proportions. We investigated associations between birth month and anthropometry among rural highland (n = 162) and urban lowland (n = 184) Peruvian children aged 6 months to 8 years. Stature; head‐trunk height; total limb, ulna, tibia, hand, and foot lengths; head circumference; and limb measurements relative to head‐trunk height were converted to internal age‐sex‐specific z scores. Lowland and highland datasets were then analyzed separately for birth month trends using cosinor analysis, as urban conditions likely provide a more consistent environment compared with anticipated seasonal variation in the rural highlands. Among highland children birth month associations were significant most strongly for tibia length, followed by total lower limb length and stature, with a peak among November births. Results were not significant for other measurements or among lowland children. The results suggest a prenatal or early postnatal environmental effect on growth that is more marked in limb lengths than trunk length or head size, and persists across the age range studied. We suggest that the results may reflect seasonal variation in maternal nutrition in the rural highlands, but other hypotheses such as variation in maternal vitamin D levels cannot be excluded. Am J Phys Anthropol 154:115–124, 2014. © 2014 The Authors. American Journal of Physical Anthropology Published by Wiley Periodicals, Inc.     

Bio-cultural effects in medieval populations

Male skeletons from medieval archaeological sites are analysed to assess differences in stature and body proportions related to the bio-cultural environment, such as social, economic, and health factors. Environmental factors, such as climate change in the course of the Middle Ages, did not have statistically significant effect on body proportions in these samples. The results show a relationship between bio-cultural factors and physique in the analysed populations that indicate stunted growth in height and weight in a leprosarium population with a low socio-economic and health status. A high-status monastic population is characterised by a stocky build, i.e., increased weight for height and relatively shorter limbs, while a medieval parish population has a linear build, i.e., relatively long limbs for height and decreased weight for height. These characteristics, relative weight for height and relative limb length, changed during the course of the Middle Ages, as did stature.     

Relationships between some maternal factors and pregnancy outcome

This study, carried out on mother-infant pairs in obstetric hospitals in Istanbul, was designed to investigate the impact of some maternal parameters on pregnancy outcome as well as to provide information on birth weight, and incidence of low birth weight, preterm birth, and small for gestational age birth. Low birth weight, preterm birth, and fetal malnutrition are among major risk factors influencing perinatal, neonatal, and postneonatal mortality and morbidity. Reported values for prepregnancy body weight and postpartum measurements of stature, weight, mid-upper arm circumference showed that the women in this series did not have caloric undernutrition, while nearly 9% were of low stature. Maternal stature, postpartum body weight, and postpartum weight and height values were found to be important determinants of birth weight. The frequency of preterm births in this series corresponds fairly well with that found in another group of Turkish mother-infant pairs in which gestational age was determined by Dubowitz scoring. In agreement with many previous studies, maternal stature and body weight stood out as important influences on the outcome of pregnancy in this series. Overall, the nutritional state of the mother prior to pregnancy is the most important determinant of birth weight.     

Altitude and growth: a study of the patterns of physical growth of a high altitude Peruvian Quechua population

Data on physical growth were obtained for a sample of 1202 Quechua subjects, aged 2 to 35 years from the district of Nuñoa, Puno, located in the southern highlands (altitude 4000–5500m) of Peru. These data were supplemented by a three-year longitudinal study of 300 subjects, aged 1 to 22 years. The patterns of physical growth of members of the indigenous population of Nuñoa are characterized by (1) late sexual dimorphism, (2) slow and prolonged growth in body size, (3) late and poorly defined adolescent stature spurt in both males and females, and (4) accelerated development in chest size. The socio-economic factors associated with urban-rural and altitude differences appear to be reflected in greater deposition of subcutaneous fat and increased weight but do not seem to influence the development of stature. We suggest the pattern of growth of this population is related to the hypoxic effects of high altitude, and/or reflects a genetic adaptation to such stress. The anthropometric and physiological studies conducted during this and previous studies and the comparative data from Peruvian populations situated at lower altitudes document the specific adaptive response of the chest wall to the hypoxic effects of high altitude.     

Thermal environment and human birth weight

Human birth weight is known to be influenced by several factors, including maternal energy supply, maternal stature, disease status, smoking status and gestation length. This article proposes that the thermal environment may be a further factor influencing birth weight. Experimental animal studies demonstrate clear effects of thermal stress on placental function and birth weight, but may have limited relevance for humans due to between-species differences in pregnancy physiology. Observational studies suggest an inverse relationship between environmental temperature and birth weight within and between human populations. Variation in maternal size, body fatness, pregnancy weight gain and heat production is predicted to influence maternal thermoregulatory capacity, as are the size and composition of the foetus. These associations generate the hypothesis that low birth weight in hot environments may in part represent an adaptation to environmental heat stress.     

Association of birth weight and length with air temperature, sunlight, humidity and rainfall in the city of Warsaw, Poland

Several studies have shown the month of birth effect on birth weight and height of children. The mechanism of this phenomenon is not fully explained. Using data from Warsaw hospitals, the influence of four climatic factors (temperature, sunlight, humidity and rainfall) on birth outcomes was studied. The sample consisted of 10,631 neonates (5450 boys and 5181 girls) born between May 2004 and April 2005. Individual values for birth weight and length were standardised on the overall mean and standard deviation for all subjects, separately for each sex. Differences in means of Z-score birth outcomes between months, seasons and semi-annual periods of birth were assessed by one-way analysis of variance, separately for each sex. The relation between average values of four atmospheric factors and average neonatal outcomes for each month of birth was assessed by a weighted Spearman rank correlation. The results revealed significant differences in average Z-scores of neonate weight and length between months of birth for boys and girls. Significant seasonal variation in Z-scores means was only found for birth length in boys. The correlation between four atmospheric factors during pregnancy and birth length was the highest for boys and occurred in the second trimester. Second trimester of fetal growth is the period most sensitive to influences of climatic factors.     

Trends in stature in the South Australian Aboriginal Murraylands

Millennial and secular changes in body height of prehistoric and recent Aboriginal South Australians are investigated. Skeletal remains of 55 male and 40 female individuals who were excavated at Roonka on the River Murray were dated from 9800 to 100 years BP. Stature was reconstructed by using humerus, femur, and tibia ratios to stature derived from Abbie's (1975) data on living Aborigines and the Trotter-Gleser method for blacks. The respective averages were 1,652 mm and 1,665 mm for males and 1,527 mm and 1,549 mm for females. In 1996/1997, statures of 27 adult males and 21 adult females were measured in Aboriginal centers of Gerard and Raukkan (Point McLeay) on the Lower River Murray. These people, as far as it can be ascertained, are the descendants of the people from Roonka. Their statures were adjusted for the stature loss with age, so that the data represent young individuals (≤30 years of age). The average male stature was 1,712 mm, and the average female stature was 1,567 mm. Data collected by Wood Jones and Campbell in 1924 for Aboriginal South Australians show that young adult male stature was 1,668 mm (n = 6), and female stature was 1,552 mm (n = 4). Slopes of regressions of individual statures on radiocarbon dates and on dates of birth are not significantly different from zero. The same is true for regressions of individual long bone lengths on radiocarbon dates. It can be concluded that there was little change in stature of Aboriginal South Australians from prehistoric to recent times. Regressions of individual age-corrected heights on birth dates (1860–1980) of Aboriginal men and women measured in 1924 and in 1996 further indicate no significant increase in height in either sex. Am J Phys Anthropol 106:505–514, 1998. © 1998 Wiley-Liss, Inc.     

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.     

Developmental,genetic, and environmental components of aerobic capacity at high altitude

The aerobic capacity of 268 subjects (158 males and 110 females) was evaluated in La Paz, Bolivia situated at 3,750 m. The sample included 1) 39 high altitude rural natives (all male); 2) 67 high altitude urban natives (32 male, 35 female); 3) 69 Bolivians of foreign ancestry acclimatized to high altitude since birth (37 male, 32 female); 4) 50 Bolivians of foreign ancestry acclimatized to high altitude during growth (25 male, 25 female); and 5) 43 non-Bolivians of either European or North American ancestry acclimatized to high altitude during adulthood (25 male, 18 female). Data analyses indicate that 1) high altitude urban natives, acclimatized to high altitude since birth or during growth, attained higher aerobic capacity than subjects acclimatized to high altitude during adulthood; 2) age at arrival to high altitude is inversely related to maximum oxygen consumption (V?O² max) expressed in terms L/min or ml/min/kg of lean body mass, but not in terms of ml/min/kg of body weight; 3) among subjects acclimatized to high altitude during growth, approximately 25% of the variability in aerobic capacity can be explained by developmental factors; 4) as inferred from evaluations of skin color reflectance and sibling similarities, approximately 20 to 25% of the variability in aerobic capacity at high altitude can be explained by genetic factors; 5) except among the non-Bolivians acclimatized to high altitude during adulthood, the aerobic capacity of individuals with high occupational activity level is equal to the aerobic capacity of high altitude rural natives; and 6) the relationship between occupational activity level and aerobic capacity is much greater among subjects acclimatized to high altitude before the age of 10 years than afterwards. Together these data suggest that the attainment of normal aerobic capacity at high altitude is related to both developmental acclimatization and genetic factors but its expression is highly mediated by environmental factors, such as occupational activity level and body composition. © 1995 Wiley-Liss, Inc.     

Indirect evidence for the genetic determination of short stature in African Pygmies

Central African Pygmy populations are known to be the shortest human populations worldwide. Many evolutionary hypotheses have been proposed to explain this short stature: adaptation to food limitations, climate, forest density, or high mortality rates. However, such hypotheses are difficult to test given the lack of long-term surveys and demographic data. Whether the short stature observed nowadays in African Pygmy populations as compared to their Non-Pygmy neighbors is determined by genetic factors remains widely unknown. Here, we study a uniquely large new anthropometrical dataset comprising more than 1,000 individuals from 10 Central African Pygmy and neighboring Non-Pygmy populations, categorized as such based on cultural criteria rather than height. We show that climate, or forest density may not play a major role in the difference in adult stature between existing Pygmies and Non-Pygmies, without ruling out the hypothesis that such factors played an important evolutionary role in the past. Furthermore, we analyzed the relationship between stature and neutral genetic variation in a subset of 213 individuals and found that the Pygmy individuals' stature was significantly positively correlated with levels of genetic similarity with the Non-Pygmy gene-pool for both men and women. Overall, we show that a Pygmy individual exhibiting a high level of genetic admixture with the neighboring Non-Pygmies is likely to be taller. These results show for the first time that the major morphological difference in stature found between Central African Pygmy and Non-Pygmy populations is likely determined by genetic factors.     

Geographical height variation among Ohio Caucasian male convicts born 1780–1849

To more completely answer questions regarding health in the past, social scientists are utilizing previously underutilized data sources. This study focuses on one such source: penitentiary records, in order to examine geographical variation in height from a sample of 2554 male Caucasian convicts aged 23-45 years. Data collected include height, age, ancestry, nationality, and year and place of birth. Birth places were divided into five geographical areas corresponding roughly to the United States census geography divisions. Average stature for this sample was 68.4+/-2.5 in. (173.7+/-6.4 cm). Regression analyses on height, birth cohort, ancestry, nationality, and place of birth indicate significant but small differences in height across geographical areas. No significant differences were found due to birth cohort.     

九寨沟水生植物群落β多样性特征研究

通过典型样地调查,运用β多样性的Wilson-Shmida指数(βT)和Bray-Curtis指数(CN)分别对九寨沟水生植物群落进行测度。结果显示,九寨沟水生维管植物种类共有75种,主要群落类型有11种,以挺水植物群落类型为主,兼有少量的沉水植物群落。β多样性测度表明,样地间种类组成随海拔梯度及其他因子的变化差异比较明显,CN1、CN2和CNN3的数量数据测度结果有差异,以重要值为基础的CN3指数具有较强的综合性和稳定性。海拔梯度和空间聚类分析表明,海拔梯度是影响水生植物群落β多样性变化的主要因子,随着海拔升高和落差的增大,β多样性变化明显,种类组成变化愈显著。同时,β多样性数量数据可以划分成四种类型,Ⅲ型的非海拔梯度因子作用结果说明流域特征和群落类型会对多样性的变化产生一定影响。       

Altitude effects on spatial components of vascular plant diversity in a subarctic mountain tundra

Environmental gradients are caused by gradual changes in abiotic factors, which affect species abundances and distributions, and are important for the spatial distribution of biodiversity. One prominent environmental gradient is the altitude gradient. Understanding ecological processes associated with altitude gradients may help us to understand the possible effects climate change could have on species communities. We quantified vegetation cover, species richness, species evenness, beta diversity, and spatial patterns of community structure of vascular plants along altitude gradients in a subarctic mountain tundra in northern Sweden. Vascular plant cover and plant species richness showed unimodal relationships with altitude. However, species evenness did not change with altitude, suggesting that no individual species became dominant when species richness declined. Beta diversity also showed a unimodal relationship with altitude, but only for an intermediate spatial scale of 1 km. A lack of relationships with altitude for either patch or landscape scales suggests that any altitude effects on plant spatial heterogeneity occurred on scales larger than individual patches but were not effective across the whole landscape. We observed both nested and modular patterns of community structures, but only the modular patterns corresponded with altitude. Our observations point to biotic regulations of plant communities at high altitudes, but we found both scale dependencies and inconsistent magnitude of the effects of altitude on different diversity components. We urge for further studies evaluating how different factors influence plant communities in high altitude and high latitude environments, as well as studies identifying scale and context dependencies in any such influences.     

内蒙古贺兰山啮齿动物群落多样性及其与环境因子关系

啮齿动物群落结构可以反映生态环境特征。本研究对处于阿拉善荒漠区呈“孤岛”状态的内蒙古贺兰山国家级自然保护区内啮齿动物的种类、分布型及群落多样性进行系统研究。将内蒙古贺兰山划分为五种生境类型,于2013年春、夏、秋3季共布设有效铗日18748个,捕获啮齿动物235只,分属2目5科11属13种。在整体研究区域,阿拉善黄鼠（Spermophilus alashanicus）为优势种。明确了喜湿型是本研究区域的主要分布型,占捕获啮齿动物的54%,并且在中低海拔区域,随着海拔的升高,喜湿型所占比例增加。受“边缘效应”的影响,山地荒漠和荒漠草原生境以及山地草原灌丛生境的啮齿动物群落多样性指数高于其他生境,除环境因素外,啮齿动物群落的多样性受两种因素的影响,既可随群落内物种数量的增加而增大,同时又受制于群落内部物种分布的均匀程度。冗余分析结果表明,植被高度、植被盖度、灌木（乔木）高度和海拔4个环境因子是决定啮齿动物群落结构最主要的环境因子,其中植被盖度与群落多样性呈负相关,随着植被盖度的增加,多样性指数随之减低。     

Decline of height with age in adults in a general population sample: estimating maximum height and distinguishing birth cohort effects from actual loss of stature with aging

The decline in stature with age among adults is well documented. Although part of this represents a birth cohort effect, actual height declines among older individuals are known to contribute to the effect. In this study we used longitudinal changes in the heights of adults in a general population sample to determine the rate of decline in height over time in individuals of different ages. This allowed an estimation of the age at which decline in height begins, a value close to age 40 in both sexes. It also allowed derivation of equations from which the maximum height of subjects can be estimated on the basis of their sex, current height, and age. These equations should prove useful when examining the effect of aging per se on physiological measurements that are height dependent. The data also allow one to compare the magnitude of the effect of year of birth with that of the actual decline in height seen among the elderly. We estimate that approximately 60% of the smaller stature of older male subjects and 45% of the smaller stature of older female subjects is a birth cohort effect deriving from the secular trend toward greater stature; the remainder is a result of an actual decrement in height after the age of 40.     

Adult height distribution in subjects born small for gestational age

The aim of the study was to investigate the post-natal growth of subjects born small for gestational age (SGA) by describing adult height distribution and by testing the effects of parental, neonatal and pregnancy-related parameters on the risk for adult short stature. The study population was made of adults selected on birth data from a maternity registry and born either small (SGA, n = 734, birth weight < 10th percentile) or appropriate for gestational age (AGA, n = 886, 25th < birth weight < 75th percentile) in whom anthropometric parameters were measured at 22 years of age. The SGA group demonstrated significantly reduced body size in comparison to the AGA group with a mean loss of 0.7 standard deviation (SD) in adult height. The frequency of adult short stature (< -2 SD) was 10.3% in the SGA group vs. 2.4% in the AGA group (p = 0.0001), adult height < -2.5 SD was observed in only 3.7% of the SGA group. Maternal (OR = 0.31 (0.16-0.62), p = 0.0001) and paternal (OR = 0.45 (0.31-0.67), p = 0.0001) heights and subjects birth length (OR = 0.78 (0.62-0.99), p = 0.04) significantly influenced the risk of adult short stature. In summary, post-natal growth defect remains moderate in the majority of subjects born SGA and < 4% only will end up with severe short stature requiring GH therapy according to most current recommendations. The role of parental height and birth length suggests that adult short stature in SGA subjects results at least in some cases from a familial and likely genetic growth disorder with antenatal onset.     

Birth weight and environmental heat load: a between-population analysis

Low birth weight, a major cause of infant morbidity and mortality, is caused by different factors in Western and developing-country populations. In addition to differing in terms of ethnicity, maternal size, maternal nutritional status, and disease load, developing-country and Western populations are also characterized by different environmental heat loads. Thermodynamic theory predicts that heat stress is mitigated by reduced size of both mother and offspring, and therefore generates the hypothesis that reduced birth weight may be an adaptation to environmental heat load. The aim of this study was to test the hypothesis that environmental heat load is associated with between-population variability in birth weight. Data on birth weight and thermal environment were obtained from the literature for 140 populations. Further data on several physical, social, and biological confounders were also collated. After adjusting for confounding factors, of which only maternal height and per capita gross domestic product were statistically significant, heat stress showed a significant inverse relationship with birth weight in 108 populations, accounting for an additional 9.6% of the between-population variance. Though based on data collected from more than one source, these results are consistent with the hypothesis that heat stress is inversely associated with birth weight, as previously reported for within-population studies. Further studies are needed to establish to what extent heat stress is a determinant of low birth weight in developing countries.     

Genetic and Environmental Influences on the Tracking of Body Size from Birth to Early Adulthood

Objective: This study identified genetic and environmental influences on the tracking of body size from birth to 16 to 18.5 years of age. Research Methods and Procedures: Longitudinal information was collected from a nationally representative sample of Finnish twin adolescents (birth cohorts 1975 to 1979) and their parents through questionnaires mailed when the twins were ages 16 and 18.5 years old. The sample included 702 monozygotic, 724 same‐sex dizygotic, and 762 opposite‐sex dizygotic sets of twins. The measures used were length, weight, ponderal index (kilograms per cubic meters), and gestational age at birth, and height, weight, and body mass index (kilograms per square meters) at 16 to 18.5 years of age. The changes in genetic and environmental influences on body size from birth to early adulthood were analyzed by quantitative genetic modeling. Results: The twins who had a higher weight or ponderal index at birth were taller and heavier in early adulthood, whereas those who were longer at birth were taller, but not heavier, later in life. Adult height was affected more by the birth size than body mass index. In the genetic modeling analyses, the genetic factors accounting for the variation of body size became more apparent with age, and both genetic and environmental influences on stature had a sizable carry‐over effect from birth to late adolescence, whereas for relative weight, the influences were more age‐specific. Discussion: The genetic and environmental architecture of body size changes from birth to adulthood. Even in monozygotic twins who share their genetic background, the initially larger twin tended to remain larger, demonstrating the long‐lasting effects of fetal environment on final body size.     

The role of nutrition and genetics as key determinants of the positive height trend

The aim of this study was to identify the most important variables determining current differences in physical stature in Europe and some of its overseas offshoots such as Australia, New Zealand and USA. We collected data on the height of young men from 45 countries and compared them with long-term averages of food consumption from the FAOSTAT database, various development indicators compiled by the World Bank and the CIA World Factbook, and frequencies of several genetic markers. Our analysis demonstrates that the most important factor explaining current differences in stature among nations of European origin is the level of nutrition, especially the ratio between the intake of high-quality proteins from milk products, pork meat and fish, and low-quality proteins from wheat. Possible genetic factors such as the distribution of Y haplogroup I-M170, combined frequencies of Y haplogroups I-M170 and R1b-U106, or the phenotypic distribution of lactose tolerance emerge as comparably important, but the available data are more limited. Moderately significant positive correlations were also found with GDP per capita, health expenditure and partly with the level of urbanization that influences male stature in Western Europe. In contrast, male height correlated inversely with children's mortality and social inequality (Gini index). These results could inspire social and nutritional guidelines that would lead to the optimization of physical growth in children and maximization of the genetic potential, both at the individual and national level.