Physical growth of Aymara children in a herding community of the Bolivian Altiplano.

In a small agropastoral Aymara community called Wariscata in the Andean Altiplano of Bolivia, anthropometric measurements were made in 1988. In comparison with those of published data for the other rural and urban Andean populations (Aymara, Quechua and Mestizo at high and low altitudes), the Aymara children of Wariscata were taller and heavier than other rural high altitude native children, but similar in height to urban high altitude children. This is possibly due to secular change of growth accompanied with nutritional improvement that has taken place in recent years. Chest width and depth had similar values to those in other Aymara children. But, Aymara children in Wariscata of both sexes had smaller chest dimensions (depth and width) than those of Quechua children. However, these ethnic differences in chest dimensions were not reflected in the adult Aymara and Quechua, suggesting different process of chest growth in Aymara and Quechua populations.     

Effect of altitude on the lung function of high altitude residents of European ancestry

The forced vital capacity (FVC), forced expiratory volume in one second (FEV), and ratio of FEV to FVC (%FEV) of 161 male and 158 female youths of European ancestry who were born at high altitudes and who were residing in La Paz, Bolivia (average altitude of 3,600 m) were examined and compared with those for lowland Europeans and highland Aymara Amerindians. FVC and FEV were significantly larger (p less than .001) in the La Paz Europeans than in two lowland control samples of European ancestry, with the relative differences between samples varying from small (1.5-4.1%) to moderate (7.7-11.9%). It could not be determined whether the enhanced lung volumes of the La Paz European children were acquired through an accelerated development of lung volumes relative to stature during adolescence, as is the case for Amerindian highlanders. After controlling for body and chest size, FVC and FEV were significantly smaller in the La Paz Europeans than in highland Aymara (p less than .001), suggesting that the lung volumes of the Aymara are influenced by factors other than simply growth and development at high altitude. Finally, as found in Amerindians, chest size is an important determinant of intra-individual variation in lung function among highland Europeans.     

Child growth and the economic value of children in rural Bolivia

Previous investigations have yielded contradictory conclusions concerning the importance of the economic contribution of children to households in agricultural societies. The present study evaluates the significance of children 's economic input in rural Ancoraimes, Bolivia by using child growth as an indirect indicator of the economic value of children. Children whose households differed in size and age composition were compared on the basis of five anthropometric measurements. Children from households with many young, nonproducing children were found to be significantly smaller for their age than children from households with few nonproducing children. Absolute household size had no major effect on child growth. While young children have a negative effect on the growth of children in the household, the positive effect of children as they grow older appears to make up for this loss. In terms of child growth, children are neither a net liability nor a net asset to agricultural households in Ancoraimes.     

Differences in physical growth of Aymara and Quechua children living at high altitude in Peru

Physical growth of Amerindian children living in two Aymara and three Quechua peasant communities in the Andean highlands of southern Peru (altitude 3,810–3,840 m) was studied, taking into account differences in the microclimate, agronomic situation, and sociodemographic variables. Anthropometric measurements were taken in 395 children aged under 14 years of age in a sample of 151 families in these communities, who were surveyed for sociodemographic variables as well. Data on the land system were available for 77 families. In comparison with reference populations from the United States (NCHS) and The Netherlands, stature, weight, head circumference, and midupper arm circumference (but not weight for stature) in the sample children were reduced. Growth retardation increased after the age of 1 year. Stature and weight in the present sample were very similar compared with previously published data on growth of rural Aymara children living near Lake Titicaca in Bolivia. Head circumference, midupper arm circumference, and weight for stature were significantly larger in Aymara children compared with Quechua children. Land was significantly more fragmented in Aymara compared with Quechua families, but amount of land owned was not different. Perinatal and infant mortality was elevated in Aymara vs. Quechua communities. Most families in Aymara communities used protected drinking water. One Quechua community had a severe microclimate, grim economic outlook, and weak social cohesion. Children in this community showed significant reductions in weight and midupper arm circumference compared with their peers in the other communities. We conclude that (presumably nutritionally mediated) intervillage and Aymara-Quechua differences in childhood physical growth existed in this rural high-altitude population in Peru and were associated with microclimate and the village economy, sociodemographic factors, and differences in the land system. © 1993 Wiley-Liss, Inc.     

Growth of Qinghai Tibetans living at three different high altitudes

This study compares the stature, weight, skinfolds, upper arm muscle area, and chest dimensions of Tibetan children, adolescents, and young adults who were born and raised, or who had lived from infancy, at 3,200 m, 3,800 m, and 4,300 m in Qinghai Province, People's Republic of China. While the individuals measured in Qinghai are among the tallest and heaviest Tibetans reported in the literature, they are nevertheless smaller and lighter than well-off children living at low altitude. The pattern of size variation among Tibetan males and females measured at the three high altitudes, along with evidence of a secular trend at 4,300 m, suggests that nutrition may significantly effect growth at high altitude. Only minor differences in thorax dimensions exist between Tibetan males and females measured at 3,200 m and 3,800 m. However, Tibetan males at 4,300 m possess slightly narrower and deeper chests (during and after adolescence) than males at 3,200 m and 3,800 m. Since individuals from 3,800 m and 4,300 m belong to the same local populations, this characteristic is unlikely to be genetically determined. However, it may be related to differences in the degree of hypoxia or to the influences of other environmental conditions.     

Evolved priors for ethnolinguistic categorization: A case study from the Quechua–Aymara boundary in the Peruvian Altiplano

Ethnic categories uniquely structure human social worlds. People readily form stereotypes about these, and other social categories, but it is unclear whether certain dimensions are privileged for making predictions about strangers when information is limited. If humans have been living in culturally-structured groups for much of their evolutionary history, we might expect them to have adaptations for prioritizing ethno-linguistic cues as a basis for making predictions about others. We provide a strong test of this possibility through a series of studies in a field context along the Quechua–Aymara linguistic boundary in the Peruvian Altiplano where the language boundary is not particularly socially meaningful. We find evidence of such psychological priors among children and adults at this site by showing that their age, and the social categories’ novelty affect participants’ reliance on ethno-linguistic inductive inferences (i.e. one-to-many predictions). Studies 1–3 show that participants make more ethno-linguistic inferences when the social categories are more removed from their real-world context. Additionally, in Study 4 when the category is marked with acoustic cues of language use, young children rely heavily on ethno-linguistic predictions, even though adults do not.     

Maximal exercise capacity in adolescent European and Amerindian high-altitude natives

Forty-seven highland natives were given maximal exercise tests on a treadmill ergometer at 3,600 m. The subjects were grouped into four subsamples on the basis of ethnicity (European vs. Aymara) and age (young vs. old adolescent). Two-way ANOVA indicated that VO2max adjusted for body size did not differ significantly between ethnic groups but was significantly larger in older than younger boys within each ethnic group (p less than .05). This finding does not support the hypothesis that Amerindian highland natives have adapted genetically to hypoxia but is consistent with the hypothesis that the relatively high VO2max's of highlanders are acquired by developmental adaptation. Several measures of ventilation and oxygen transport capacity differed significantly between ethnic groups, suggesting that growing European and Aymara boys may respond somewhat differently to the stress of high-altitude hypoxia. However, despite these differences, VO2max, an integrated measure of the overall functional capacity of the oxygen transport system, did not differ significantly between ethnic groups, suggesting that both groups are equally capable of meeting the body's oxygen requirements during maximal exercise at high altitude.     

The Aymara of Western Bolivia. II. Maxillofacial and dental arch variation

Maxillofacial and dental arch dimensions of the Bolivian Aymara population are age and sex dependent. Interpopulational comparisons reveal these dimensions to differ from those seen in Aleuts, Australian aborigines, and Swedes, but to be similar to those of the indigenous Taiwanese. Finally, these dimensions are not the same in Aymara of unmixed ancestry, and Mestizos residing in the same villages.     

Higher arterial oxygen saturation during submaximal exercise in Bolivian Aymara compared to European sojourners and Europeans born and raised at high altitude

Arterial oxygen saturation (SaO(2)) was measured at 3,600-3,850 m by pulse oximetry at rest and during submaximal exercise in three study groups: 1) highland Aymara natives of the Bolivian altiplano (n = 25); 2) lowland European/North American sojourners to the highlands with at least 2 months of acclimatization time to 3,600 m (n = 27); and 3) subjects of European ancestry born and raised at 3,600 m (n = 22). Aymara subjects maintained approximately 1 percentage point higher SaO(2) during submaximal work up to 70% of their maximal work capacity, and showed a smaller rate of decline in SaO(2) with increasing work compared to both European study groups. The higher-exercise SaO(2) of Aymara compared to Europeans born and raised at 3,600 m suggests genetic adaptation. The two European study groups, who differed by exposure to high altitude during their growth and development period, did not show any significant difference in either resting or exercise SaO(2). This suggests that the developmental mode of adaptation is less important than the genetic mode of adaptation in determining exercise SaO(2). A weak correlation was detected (across study groups only) between the residual forced vital capacity (FVC) and the residual SaO(2) measured at the highest level of submaximal work output (P = 0.024, R = 0.26). While firm conclusions based on this correlation are problematic, it is suggested that a part of the higher SaO(2) observed in Aymara natives is due to a larger lung volume and pulmonary diffusion capacity for oxygen. Results from this study are compared to similar studies conducted with Tibetan natives, and are interpreted in light of recent quantitative genetic analyses conducted in both the Andes and Himalayas.     

Sex differences in age structure, growth rate and body size of common frogs Rana temporaria in the subarctic

The thermal environment and length of the activity season are important factors in shaping life-history trait variation in ectotherms. Many ectothermic vertebrates living at high latitudes or altitudes tend to be larger and older than their conspecifics living at lower latitudes or altitudes. However, detailed data on age, body size and growth variation—and how they may differ between males and females—are still scarce, especially from extreme high-latitude environments. We studied growth (body length increment), age and size structure of common frogs (Rana temporaria) in subarctic Finland (69°04′N) by applying skeletochronological methods to individually marked adults (n?=?169) captured and recaptured between 1999 and 2003. We found that breeding males were on average younger (mean?=?8.5?years) than females (11.9?years) and that males started reproducing earlier (≥3–4?years of age) than females (>4–5?years). The oldest encountered individual was an 18-year-old female, which to our knowledge is the oldest wild common frog ever reported. Females were on average larger (mean body length?=?76.6?mm) than males (70.7?mm), and this appeared to be mainly due to their older age as compared to males. While body length increased and growth rate decreased with age in both sexes, growth rate declined significantly faster with age in males than in females. The latter finding provides a proximate explanation for the observation that even after accounting for age differences among sexes (females?>?males), females were longer than males.     

Heterozygosity and craniofacial dimensions of Zapotec school children from a subsistence community in the valley of Oaxaca, southern Mexico

Gene flow is associated with differences in craniofacial and postcranial dimensions among indigenous populations of southern Mexico. This study compares four craniofacial dimensions in 322 children from families which have an average inbreeding coefficient of 0.01 and 36 children from families which have an inbreeding coefficient of zero (more heterozygous) in a Zapotec speaking community. In addition, two indices were computed. With sex and chronological age constant, there is a statistically significant difference between more and less heterozygous children in bizygomatic diameter. Differences in biparietal diameter and fronto-occipital length reflect the same tendency. The differences probably reflect more an effect of heterozygosity on these dimensions than facial dissimilarity of the populations from which the new genetic materials were drawn because gene flow was from related groups of Indians (e.g., Mixtec) in southern Mexico. Hence, midface growth and overall normal size appear to be affected by fluctuation in level of heterozygosity.     

Haematology and erythrocyte metabolism in man at high altitude: an Aymara-Quechua comparison

In the course of haematological and biological investigations among Aymara and Quechua populations in Bolivia, an anthropological study of the erythrocytary respiratory function was carried out on the two groups at two altitudes: 3,600 m and 450 m. A difference in the intensity of the biological variations of the two populations is observed at high altitude. In the Quechuas, as in any lowland native, the adaptative phenomena are totally and quickly reversible. In the Aymaras, we detected the existence of more marked haematological and biochemical characters: moderate polycythemia, hyperhaemoglobinemia, microcytosis, metabolical hyperactivity with accumulation of 2-3 di-phosphoglycerate and ATP, and methaemoglobinemia with a drop in the activity of the methaemoglobin reductases. The Aymaras preserve some of those characters (methaemoglobinemia excepted) when they settle in lowlands.     

Age differences in craniofacial dimensions among adults from Indian Knoll,Kentucky

Adult craniofacial expansion with aging has recently been documented in a living US white population sample (Israel, '73a, '77). The present study extends these findings to a prehistoric Amerindian skeletal sample from the Indian Knoll, Kentucky site. Sixteen craniofacial dimensions available for 136 adult males were compared in younger (20–34 years) and older (35–50 years) age groups. Of these, six dimensions showed a significant difference between age groups; all significantly different dimensions were larger in the older adult age group. The multivariate (T²) difference between age groups was highly significant. Comparison of results before and after a size standardization indicated that the majority of differences between age groups were associated with an overall size increase, or expansion with aging, and did not represent merely remodeling, or “shape” changes. The pattern of craniofacial change with age appeared generally similar to that observed in the modern US white sample; however, some differences were noted. It is shown that the age trends observed at Indian Knoll are most likely to reflect true craniofacial growth in size among the adult male inhabitants of the site, rather than secular trends or other artifacts of the sampling procedure. The causes for continuing adult craniofacial expansion are unknown, and probably involve a complex interaction of many factors. However, this pattern of change with age among adults does appear to be characteristic of population samples of widely differing genetic and environmental backgrounds.     

Reproduction in high altitude Aymara: physiological stress and fertility planning?

Reproductive characteristics at high altitude are described based on the reproductive histories of 720 Aymara women, collected in 1998 and 1999 in a group of twelve peasant communities at a mean altitude of 4000 m in the Bolivian Altiplano. The reproductive pattern is shaped by a late onset of childbearing, associated with a rather short reproductive span and large birth intervals. Environmental conditions could explain the particularly late age at menarche of rural girls compared with their urban counterparts, whereas the age at first birth is likely to be under cultural control. The short reproductive span appears to result from a large mean interval between last birth and menopause, which is essentially determined by cultural decisions. The birth intervals, which are longer than in many traditional societies, could be the result of a slower restoration of postpartum fecundability induced by the hard way of life inherent in the Altiplano (including poor sanitary and nutritional conditions and high workload), perhaps aggravated by hypoxia. However, a secular trend in fertility is perceptible, towards earlier menarche, earlier age at first birth, increasing reproductive span and a slight increase in live births and surviving offspring, which is probably the result of a slow improvement in living conditions. The existence of birth control on the one hand, and a total fertility rate averaging six live births among the couples who do not practise contraception on the other, are other arguments against the hypothesis of a low natural fecundity in these Aymara groups.     

Altitude,heredity and body proportions in northern Chile

Recent studies of the effects of hypoxia on human growth and adult size have focused mainly on the variability of single measurements. In this paper we explore changes with altitude and ethnicity (Spanish-Aymara ancestry) in body proportions of permanent residents of an altitudinal gradient (0–4000 meters) in northern Chile. Body proportion or shape is assessed by anthropometric indices and principal components of 14 bone measurements. Ethnicity independent of altitude had its major effect on proportions and a lesser effect on size. Aymara had larger relative sitting heights, broader builds and prominent facial development as compared to non-Aymara (Spanish). Altitude also affected head and chest proportions during growth. On the whole, the effects of altitude and Aymara ancestry on the measurements and indices were independent (not necessarily of similar direction or magnitude), in spite of a correlation of ethnicity and altitude in Andean populations.     

Neonatal Variables,Altitude of Residence and Aymara Ancestry in Northern Chile

Studies performed in the Andean plateau, one of the highest inhabited areas in the world, have reported that reduced availability of oxygen is associated to fetal growth retardation and lower birth weight, which are established predictors of morbidity and mortality during the first year of life. To test this hypothesis, perinatal variables of neonates born at the Juan Noé Hospital of Arica, Chile, were analyzed in relation to altitude of residence and Aymara ancestry of their mothers. The study population comprised the offspring of 5,295 mothers born between February 2004 and August 2010. Information included birth weight, height, head circumference, gestational age, altitude of residence and socioeconomic status, and was obtained from medical records. Mother´s ancestry was assessed based on surnames which were linked to percentages of Aymara admixture estimates relying on 40 selected ancestry informative markers. After correcting for the effect of multicollinearity among predictor variables, neonates born to mothers with an increased component of Aymara ancestry showed significantly higher birth weight and height at sea level, a marginally significant (p-value 0.06) decrease of birth weight and a significant decrease of height with altitude in comparison with the offspring of mothers with low Aymara ancestry. Since observed tendencies are suggestive of a possible genetic adaptation to hypoxia of the Chilean Aymara, we discuss briefly preliminary evidence related to fetal oxygen transport, particularly polymorphisms in the promoters of the HBG1 and HBG2 genes that are modulators of HbF synthesis, obtained in this ethnic group.     

青藏高原与安第斯高原地区儿童青少年的身高、体重和胸围的对比

通过青藏高原和安第斯山高原地区儿童青少年身高、体重和胸围的比对,探讨高原地区儿童青少年生长发育的规律和特点,找出儿童青少年生长发育的高原地区差异,进一步改善高原地区居民的健康状态,促进儿童青少年生长发育,为高原医学和高原人类学的发展提供理论基础。本文以青藏高原和安第斯山高原地区儿童青少年为研究对象。选择在西藏出生长大、经体检证明身体健康6-21岁藏族男女(父母3代藏族)共2813例有效样本(男,1417例;女,1396例),在知情同意情况下直接测量了身高、体重和胸围。印度、秘鲁、玻利维亚、智利等国家和地区儿童青少年生长发育资料从文献中获取。去除不完整的无法比较及年代过于久远的材料,排除小样本及数据不全和不符合要求的样本,严格控制质量。所有测量数据输入SPSS13.0统计软件包。对数据进行描述性统计分析、独立样本t检验、方差分析等统计学处理。结果显示:1)青藏高原儿童青少年男女身高高于安第斯山男女。2)青藏高原儿童青少年的体重与安第斯山儿童青少年相近。3)青藏高原儿童青少年的胸围明显小于安第斯山儿童青少年。高原地区与非高原地区儿童青少年生长发育相比有相似性又有特殊性(如发育水平低,胸径较大,生长发育指标普遍低于WHO(2007)和本国国内水平)。西藏藏族儿童青少年比安第斯山的发育好,两者具有不同的体质特征,这可能与生态环境、高原缺氧、遗传因素和社会经济文化等多种因素有关。     

Cross-sectional study of electrocardiographic pattern in healthy children resident at high altitude

Electrocardiographic studies have reported persistent right ventricle predominance in high altitude children as an adaptive response. No information was provided on ethnicity and environmental factors in those studies. We assessed the electrocardiographic characteristics in healthy high altitude children with mixed ancestry and relatively high mobility to lower altitudes. A cross-sectional study of 321 children aged 2 months through 19 years old and living at high altitude (Tintaya, Peru, 4,100 m) was conducted. Standard 12-lead electrocardiography was performed. Information was obtained on ethnicity, medical history, place and altitude of pregnancy and birth, mobility of children and their parents and grandparents to lower altitudes, and housing conditions. A medical examination, echocardiography, hemoglobin, oxygen saturation, and anthropometric measurements were performed. Means between sexes were compared through Mann-Whitney test for independent samples not normally distributed. Potentially influential variables on electrocardiographic values were controlled through a general linear model. Electrocardiographic parameters including QRS axis, RV1, RSV1, RV1SV5, RSV5, RSV6, and SV1RV5 did not show a right predominance pattern at any age. Values were within sea level norms. None of the genetic or environmental factors controlled showed a consistent influence on the electrocardiographic variables. Our study showed an electrocardiographic pattern similar to that of sea level in high altitude children with some degree of high-altitude ancestry, comparatively well-nourished and with relatively high mobility to low altitudes.     

Effects of altitude, ethnicity-religion, geographical distance, and occupation on adult anthropometric characters of eastern Himalayan populations

With a view to estimating the effect of altitude on body dimensions vis-à-vis ethnicity-religion, geographical distance, and occupation, a comprehensive multivariate statistical analysis was performed on data pertaining to 16 anthropometric characters collected from 1,103 individuals (643 males and 460 females) belonging to two ethnic groups-Sherpa and Lepcha. Samples were drawn from several locations in the eastern Himalayan region-Darjeeling and Kalimpong in West Bengal (India), and Nepal, situated at low (1,000-2,000 meters) and high (above 3,500 meters) altitudes. The individuals sampled practice different occupations and follow different religions. Significant age and sex effects were observed. The data were age-adjusted, and sexes were treated separately. A test of equality of mean vectors indicated heterogeneity among population groups. Almost all characters were found to contribute significantly to the ability to discriminate between the groups. The overall probability of correctly classifying an individual based on body dimensions into the group in which she or he actually belongs was high (between 0.64 and 0.77). Shape and size factors could be identified that explained about 50% of the total variance and yielded a reasonable separation of the groups. Results of four different types of multivariate statistical analyses were in agreement, and showed that altitude is most highly associated with body dimensions.     

Effects of growth hormone treatment on left ventricular dimensions in children with Noonan's syndrome

OBJECTIVE: To study the effects of long-term growth hormone (GH) treatment on left ventricular (LV) dimensions in children with Noonan's syndrome (NS). METHODS: Echocardiographic measurements of LV dimensions were performed before and during GH treatment in 27 participants (21 boys, 6 girls) in a partly controlled 3-year trial of high-dose GH treatment (0.15 IU/kg/day). Nineteen children had a congenital heart defect, 1 of them had hypertrophic obstructive cardiomyopathy. In the first 3 years, the children were assigned to 1 of 2 groups: group A with discontinuation of GH treatment in the 3rd year, or group B without GH treatment in the 1st year. After the 3rd year, 12 of the 27 children were followed up for 2 additional years to evaluate the long-term effects of GH treatment on the heart. RESULTS: At baseline, LV internal diameters were smaller, while posterior wall thickness were thicker than normal. Over the 1st year, changes in LV dimensions were comparable between the 2 groups. No significant differences were found in LV dimensions between the situation at baseline and after 4 years of GH treatment. CONCLUSION: Long-term high-dose GH treatment does not have clinically significant adverse effects on LV dimensions in children with NS.