Hematological differences during growth among Tibetans and Han Chinese born and raised at high altitude in Qinghai,China

This study describes the hemoglobin concentration ([Hb]) and hematocrit (HCT) of over 1,000 Tibetan and Han children, adolescents, and young adults who were born and raised at 3,200 m, 3,800 m, or 4,300 m in Qinghai Province, western China. At 3,200 m, no altitude effect is evident in the hematological characteristics of either group. At 3,800 m and 4,300 m, both groups show [Hb] and HCT values that are above low-altitude norms. At both altitudes, Tibetan and Han children show no differences in the pattern of hematological response up to age 13. Among adolescents and young adults, however, the [Hb] and HCT of Han males and females are elevated compared to Tibetans. This indicates that the adolescent period may involve a divergence in the responses to hypoxia made by some individuals in these two groups. Also, many other adolescents and young adults in both groups show similar hematological characteristics, indicating that many Tibetans and Han share similar hematological responses to hypoxia.     

Ventilation and hypoxic ventilatory response of Tibetan and Aymara high altitude natives

Newcomers acclimatizing to high altitude and adult male Tibetan high altitude natives have increased ventilation relative to sea level natives at sea level. However, Andean and Rocky Mountain high altitude natives have an intermediate level of ventilation lower than that of newcomers and Tibetan high altitude natives although generally higher than that of sea level natives at sea level. Because the reason for the relative hypoventilation of some high altitude native populations was unknown, a study was designed to describe ventilation from adolescence through old age in samples of Tibetan and Andean high altitude natives and to estimate the relative genetic and environmental influences. This paper compares resting ventilation and hypoxic ventilatory response (HVR) of 320 Tibetans 9–82 years of age and 542 Bolivian Aymara 13–94 years of age, native residents at 3,800–4,065 m. Tibetan resting ventilation was roughly 1.5 times higher and Tibetan HVR was roughly double that of Aymara. Greater duration of hypoxia (older age) was not an important source of variation in resting ventilation or HVR in either sample. That is, contrary to previous studies, neither sample acquired hypoventilation in the age ranges under study. Within populations, greater severity of hypoxia (lower percent of oxygen saturation of arterial hemoglobin) was associated with slightly higher resting ventilation among Tibetans and lower resting ventilation and HVR among Aymara women, although the associations accounted for just 2–7% of the variation. Between populations, the Tibetan sample was more hypoxic and had higher resting ventilation and HVR. Other systematic environmental contrasts did not appear to elevate Tibetan or depress Aymara ventilation. There was more intrapopulation genetic variation in these traits in the Tibetan than the Aymara sample. Thirty-five percent of the Tibetan, but none of the Aymara, resting ventilation variance was due to genetic differences among individuals. Thirty-one percent of the Tibetan HVR, but just 21% of the Aymara, HVR variance was due to genetic differences among individuals. Thus there is greater potential for evolutionary change in these traits in the Tibetans. Presently, there are two different ventilation phenotypes among high altitude natives as compared with sea level populations at sea level: lifelong sustained high resting ventilation and a moderate HVR among Tibetans in contrast with a slightly elevated resting ventilation and a low HVR among Aymara. Am J Phys Anthropol 104:427–447, 1997. © 1997 Wiley-Liss, Inc.     

Sex-specific migration patterns in Central Asian populations, revealed by analysis of Y-chromosome short tandem repeats and mtDNA.

Eight Y-linked short-tandem-repeat polymorphisms (DYS19, DYS388, DYS389I, DYS389II, DYS390, DYS391, DYS392, and DYS393) were analyzed in four populations of Central Asia, comprising two lowland samples-Uighurs and lowland Kirghiz-and two highland samples-namely, the Kazakhs (altitude 2,500 m above sea level) and highland Kirghiz (altitude 3,200 m above sea level). The results were compared with mtDNA sequence data on the same individuals, to study possible differences in male versus female genetic-variation patterns in these Central Asian populations. Analysis of molecular variance (AMOVA) showed a very high degree of genetic differentiation among the populations tested, in discordance with the results obtained with mtDNA sequences, which showed high homogeneity. Moreover, a dramatic reduction of the haplotype genetic diversity was observed in the villages at high altitude, especially in the highland Kirghiz, when compared with the villages at low altitude, which suggests a male founder effect in the settlement of high-altitude lands. Nonetheless, mtDNA genetic diversity in these highland populations is equivalent to that in the lowland populations. The present results suggest a very different migration pattern in males versus females, in an extended historical frame, with a higher migration rate for females.     

Hemoglobin levels in a Himalayan high altitude population

This report presents data on hemoglobin concentrations in a sample of Himalayan high altitude natives measured at their habitual altitude of residence. In this sample of 270 healthy Tibetan adults resident at 3250–3560 m in Upper Chumik, Nepal, the mean hemoglobin concentration is 16.1 ± 1.2 gm/dl among adult males, 14.4 ± 1.4 gm/dl among premenopausal and 15.0 ± 1.1 gm/dl among postmenopausal adult females. 123 of 126 (98%) males, 96 of 100 (96%) premenopausal and 36 of 44 (82%) postmenopausal females have hemoglobin concentrations within two standard deviations of the sea level mean. These data demonstrate that a healthy population may reside at high altitude without the degree of elevation in hemoglobin widely known and cited for Andean highlanders. Comparing published data on mean hemoglobin concentrations of adult Himalayan and Andean samples residing between 3200 m and 4100 m reveals that Himalayan means are systematically lower. This in turn may account for the reported population differences in the prevalence of chronic mountain sickness (Monge's disease). It is hypothesized that Himalayan and Andean highlanders represent alternative patterns of high altitude hematological adaptation.     

Percent of oxygen saturation of arterial hemoglobin among Bolivian Aymara at 3,900–4,000 m

A range of variation in percent of oxygen saturation of arterial hemoglobin (SaO₂) among healthy individuals at a given high altitude indicates differences in physiological hypoxemia despite uniform ambient hypoxic stress. In populations native to the Tibetan plateau, a significant portion of the variance is attributable to additive genetic factors, and there is a major gene influencing SaO₂. To determine whether there is genetic variance in other high-altitude populations, we designed a study to test the hypothesis that additive genetic factors contribute to phenotypic variation in SaO₂ among Aymara natives of the Andean plateau, a population geographically distant from the Tibetan plateau and with a long, separate history of high-altitude residence. The average SaO₂ of 381 Aymara at 3,900–4,000 m was 92 ± 0.15% (SEM) with a range of 84–99%. The average was 2.6% higher than the average SaO₂ of a sample of Tibetans at 3,800–4,065 m measured with the same techniques. Quantitative genetic analyses of the Aymara sample detected no significant variance attributable to genetic factors. The presence of genetic variance in SaO₂ in the Tibetan sample and its absence in the Aymara sample indicate there is potential for natural selection on this trait in the Tibetan but not the Aymara population. Am J Phys Anthropol 108:41–51, 1999. © 1999 Wiley-Liss, Inc.     

Comparison of the reproductive performance of rats at high altitude (3,800m) and at sea level

Estrous cycles and reproductive performance were compared among rats born at high altitude, rats of Berkeley stock transported to 3,800 m, and sea level controls. Disturbances of reproductive function observed in experimental groups were not due to reduced food intake. Estrous cycles of Berkeley stock at 3,800 m were normal, whereas cycles of high altitude native rats were irregular and fertility was impaired. Litter size was reduced in both groups at high altitude with fewer implantation sites than numbers of corpora lutea observed in the Berkeley stock rats at 3,800 m. In the high altitude native animals, numbers of corpora lutea correlated with implantation sites. Placentas from Berkeley stock rats (3,800 m) were heavier than those from the other groups, and fetal hematocrits from these animals were reduced.     

青藏高原不同海拔矮嵩草蛋白质、脂肪和淀粉含量的变异

 生长在青藏高原4个不同海拔地区的矮嵩草(Kobresia humilis),其蛋白质、脂肪和碳水化合物的含量有明显差异。其中海拔最高的大坂山(4,000m)植株中蛋白质含量平均比海拔依次较低的金羊岭(3,800m),海北站(3,200m)和西宁地区(2,200m)的分别高出9.9％,17.3％和39.4％;脂肪含量平均分别高出7.1％,77.8％和106.0％;淀粉含量也平均分别高出2.4％,21.6％和32.7％。同时表明,海拔高度对上述若干生化成分含量的季节性动态变化均有明显的影响。从而显示,高海拔地区的植物所以具有较强的抗寒性和适应逆境胁迫的能力,是与体内蛋白质、脂肪和碳水化合物(淀粉)的大量积累增加密切相关。     

Deer mouse aerobic performance across altitudes: effects of developmental history and temperature acclimation

Aerobic physiology at high altitudes has been studied in many animals. Prior work on laboratory-bred deer mice (a species with a wide altitudinal range) showed depression of aerobic capacity at high altitude, even after acclimation. However, wild deer mice show no reduction in thermogenic performance at high altitude, and performance limits seem to be due to physiological and anatomical adjustments to environmental temperature and not to oxygen availability. We asked whether across-altitude performance differences exist in deer mice after accounting for temperature acclimation (approximately 5 degrees and 20 degrees -25 degrees C) and prenatal and neonatal development altitude (340 vs. 3,800 m). We measured maximal thermogenic oxygen consumption (VO2sum) in cold exposure and ran mice on a treadmill to elicit maximal exercise oxygen consumption (VO2max). We found a 10% reduction in VO2max at 3,800 m compared with that at 340 m; thus, the mice were able to compensate for most of the 37% reduction in oxygen availability at the higher altitude. Development altitude did not affect VO2max. There was no effect of test altitude or development altitude on VO2sum in warm-acclimated animals, but both test and development altitude strongly affected VO2sum in cold-acclimated mice, and compensation for hypoxia at 3,800 m was considerably less than that for exercise.     

Hemoglobin concentration of high-altitude Tibetans and Bolivian Aymara

Elevated hemoglobin concentrations have been reported for high-altitude sojourners and Andean high-altitude natives since early in the 20th century. Thus, reports that have appeared since the 1970s describing relatively low hemoglobin concentration among Tibetan high-altitude natives were unexpected. These suggested a hypothesis of population differences in hematological response to high-altitude hypoxia. A case of quantitatively different responses to one environmental stress would offer an opportunity to study the broad evolutionary question of the origin of adaptations. However, many factors may confound population comparisons. The present study was designed to test the null hypothesis of no difference in mean hemoglobin concentration of Tibetan and Aymara native residents at 3,800–4,065 meters by using healthy samples that were screened for iron deficiency, abnormal hemoglobins, and thalassemias, recruited and assessed using the same techniques. The hypothesis was rejected, because Tibetan males had a significantly lower mean hemoglobin concentration of 15.6 gm/dl compared with 19.2 gm/dl for Aymara males, and Tibetan females had a mean hemoglobin concentration of 14.2 gm/dl compared with 17.8 gm/dl for Aymara females. The Tibetan hemoglobin distribution closely resembled that from a comparable, sea-level sample from the United States, whereas the Aymara distribution was shifted toward 3–4 gm/dl higher values. Genetic factors accounted for a very high proportion of the phenotypic variance in hemoglobin concentration in both samples (0.86 in the Tibetan sample and 0.87 in the Aymara sample). The presence of significant genetic variance means that there is the potential for natural selection and genetic adaptation of hemoglobin concentration in Tibetan and Aymara high-altitude populations. Am J Phys Anthropol 106:385–400, 1998. © 1998 Wiley-Liss, Inc.     

The effects of high altitudes on child growth and development

This study compares the growth characteristics of populations of Tibetan origin living in Nepal to high altitude populations of Peru and Ethiopia. Measurements were made on two groups of children, a sample of Sherpas living in the Everest region of northeast Nepal at elevations in excess of 3500 m, and a sample of Tibetan children living in Kathmandu at an altitude of 1000 m. Although the Tibetan children showed some growth advancement over the highland sample of Sherpas, the differences were less than might have been expected on the basis of work carried out in Peru, where long established high altitude populations live at similar elevations to those of Himalayan populations. In particular, some growth trends seen in Andean populations, such as the increased diameter of the chest wall, are not seen in populations of Tibetan origin. It is suggested that genetic influences may exert a stronger effect on the growth of high altitude populations than hitherto believed.Presented the Seventh International Biometeorological Congress, 17–23 August 1975, College Park, Maryland, USA.     

青海地区藏汉族人群下颌第二磨牙根管形态的锥形束CT研究

目的:采用锥形束CT(Cone Beam CT,CBCT)技术探讨青海地区藏汉族人群下颌第二磨牙根管形态、数量以及C型根管发生率和髓腔差值的异同。方法:从2016年5月到2018年12月青大附院口腔门诊牙齿CBCT扫描结果中选择藏、汉民下颌第二磨牙各300颗,其中汉族150例,藏族150例。按照Vertucci分类对根管进行分型,探究青海地区藏、汉族人群下颌第二磨牙根管形态特点,同时对牙根类型、C型根管数量和发生率进行统计研究。结果:青海地区藏汉族人群下颌第二磨牙牙根类型以双根牙为主,且其在藏族人群中的发生率高于汉族人群。青海地区藏汉族人群下颌第二磨牙的根管分型以Ⅰ型和C型根管所占比例最高。在青海地区汉族人群和藏族人群下颌第二磨牙中,C形根管所占比率分别为40.7%和27.0%,汉族人群C型根管发生率显著高于藏族人群(P0.05)。在青海地区藏汉人群下颌第二磨牙中,女性的发生率显著高于男性(P0.05)。青海地区藏族人群的MB-DB、DB-P平均值显著高于汉族人群(P0.05)。结论:青海地区藏汉族人群下颌第二磨牙根管形态基本类似,C型根管发生率汉族人群是远远大于藏族人群的,具有一定的种族差异性。但是C型根管发生率在青海地区藏汉人群中都是女性大于男性。同时藏族人群髓腔差值也具有一定的种族差异性。     

Growth of lowland native children of European Ancestry during sojourn at high altitude (3,200 m)

The moderate growth retardation frequently observed among children living at high altitude is usually assumed to result from hypoxic stress. However, such children are frequently from the poorer socioeconomic strata of their societies and may suffer malnutrition, poor hygiene, inadequate medical care, and overcrowding—factors also associated with growth retardation. The objective of this study was to determine if there is a statistically observable alteration in the growth of middle-class children of European ancestry during sojourn at high altitude. Semilongitudinal height/weight measurements were gathered retrospectively from medical records of 18 boys and 17 girls who were born at low altitude, were well-nourished and clinically normal, and who had lived at Achoma, Peru (altitude 3,200 m), continuously for 9–36 months. Measurements were divided, by sex, into four cohorts: I (3–6 months at Achoma), II (6–12 months), III (12–18 months), and IV (18–24 months); initial, presojourn, height and weight were also obtained. All heights and weights were normalized with age-specific reference values. Changes in Z scores (ΔZ) during sojourn were calculated for each subject by subtracting the score of the presojourn value from those of cohorts I–IV. Paired t-tests revealed, among the boys, a significant decline in Z score for weight during sojourn in all four cohorts. Weight scores for the girls also declined in all four cohorts, although only the change in cohort III was significant. Height scores showed a decline with time at sojourn in the boys, but in girls there is an initial drop followed by a steady increase to presojourn levels. These results are consistent with the view that moderate hypoxia exerts a primary growth-limiting effect even on healthy, well-nourished children.     

青海藏族青少年骨龄与生长发育关系研究

本文报告了青海省境内,世居在海拔3000-4000米地区的728名7-18岁健康藏族青少年学生的手、腕部骨骼发育情况,对骨化中心出现和骨骺愈合求出了50%出现年龄,并对骨龄与青春期身高突增的关系及与月经初衬潮的关系进行了分析。     

Muscle accounts for glucose disposal but not blood lactate appearance during exercise after acclimatization to 4,300 m.

We hypothesized that the increased blood glucose disappearance (Rd) observed during exercise and after acclimatization to high altitude (4,300 m) could be attributed to net glucose uptake (G) by the legs and that the increased arterial lactate concentration and rate of appearance (Ra) on arrival at altitude and subsequent decrease with acclimatization were caused by changes in net muscle lactate release (L). To evaluate these hypotheses, seven healthy males [23 +/- 2 (SE) yr, 72.2 +/- 1.6 kg], on a controlled diet were studied in the postabsorptive condition at sea level, on acute exposure to 4,300 m, and after 3 wk of acclimatization to 4,300 m. Subjects received a primed-continuous infusion of [6,6-D2]glucose (Brooks et al., J. Appl. Physiol. 70: 919-927, 1991) and [3-13C]lactate (Brooks et al., J. Appl. Physiol. 71:333-341, 1991) and rested for a minimum of 90 min, followed immediately by 45 min of exercise at 101 +/- 3 W, which elicited 51.1 +/- 1% of the sea level peak O2 uptake (65 +/- 2% of both acute altitude and acclimatization peak O2 uptake). Glucose and lactate arteriovenous differences across the legs and arms and leg blood flow were measured. Leg G increased during exercise compared with rest, at altitude compared with sea level, and after acclimatization. Leg G accounted for 27-36% of Rd at rest and essentially all glucose Rd during exercise. A shunting of the blood glucose flux to active muscle during exercise at altitude is indicated. With acute altitude exposure, at 5 min of exercise L was elevated compared with sea level or after acclimatization, but from 15 to 45 min of exercise the pattern and magnitude of L from the legs varied and followed neither the pattern nor the magnitude of responses in arterial lactate concentration or Ra. Leg L accounted for 6-65% of lactate Ra at rest and 17-63% during exercise, but the percent Ra from L was not affected by altitude. Tracer-measured lactate extraction by legs accounted for 10-25% of lactate Rd at rest and 31-83% during exercise. Arms released lactate under all conditions except during exercise with acute exposure to high altitude, when the arms consumed lactate. Both active and inactive muscle beds demonstrated simultaneous lactate extraction and release. We conclude that active skeletal muscle is the predominant site of glucose disposal during exercise and at high altitude but not the sole source of blood lactate during exercise at sea level or high altitude.     

Socioeconomic variation in estimated growth velocity of schoolchildren from a rural, subsistence agricultural community in southern Mexico

Socioeconomic variation in estimated growth velocities (annual growth increments) of several anthropometric dimensions was considered in schoolchildren from a rural, subsistence agricultural community in the Valley of Oaxaca in southern Mexico. The children (114 males, 99 females), 6-13 years of age, were measured twice, approximately one year apart. Annual growth increments were computed by subtracting measurements taken in the fall of 1978 from those taken in the fall of 1979. Information on household land holdings and appliances and parental occupation was used to compute an index of socioeconomic status (SES). Analysis of annual increments among upper SES (65 males, 45 females) and lower (49 males, 54 females) children indicated negligible differences. The results suggest that growth deficits evident in the children at school age occurred in infancy and early childhood so that there was little, if any, SES variation in growth rate at the school ages.     

Effects of high altitude and water deprivation on arginine vasopressin release in men

High-altitude exposure changes the distribution of body water and electrolytes. Arginine vasopressin (AVP) may influence these alterations. The purpose of this study was to examine the effect of a 24-h water deprivation trial (WDT) on AVP release after differing altitude exposures. Seven healthy males (age 22 +/- 1 yr, height 176 +/- 2 cm, mass 75.3 +/- 1.8 kg) completed three WDTs: at sea level (SL), after acute altitude exposure (2 days) to 4,300 m (AA), and after prolonged altitude exposure (20 days) to 4,300 m (PA). Body mass, standing and supine blood pressures, plasma osmolality (Posm), and plasma AVP (PAVP) were measured at 0, 12, 16, and 24 h of each WDT. Urine volume was measured at each void throughout testing. Baseline Posm increased from SL to altitude (SL 291.7 +/- 0.8 mosmol/kgH2O, AA 299.6 +/- 2.2 mosmol/kgH2O, PA 302.3 +/- 1.5 mosmol/kgH2O, P < 0.05); however, baseline PAVP measurements were similar. Despite similar Posm values, the maximal PAVP response during the WDT (at 16 h) was greater at altitude than at SL (SL 1.7 +/- 0.5 pg/ml, AA 6.4 +/- 0.7 pg/ml, PA 8.7 +/- 0.9 pg/ml, P < 0.05). In conclusion, hypoxia appeared to alter AVP regulation by raising the osmotic threshold and increasing AVP responsiveness above that threshold.     

The physical growth of high altitude Bolivian Aymara children

This study describes the growth characteristics of Aymara children living in Ancoraimes, Bolivia at altitudes between 3800 and 4000 meters. Anthropometric measurements were made on 510 children between the ages of 6. 0 and 20. 9 years, 360 males and 150 females. The growth pattern of Ancoraimes Aymara children is very similar to that of other high altitude Andean populations. They are greatly delayed in height and weight, exhibit little sexual dimorphism in body size and relative to stature, have larger chest dimensions than U.S. children. Compared to Quechua children living at higher altitudes in Peru, Ancoraimes children tend to be taller and heavier but have significantly smaller chest dimensions. Although the causes of the size differences between these two groups are not entirely clear, they may be due to the different altitudes at which the groups reside.     

Finger dermatoglyphics of the Tibetans

Finger prints of 156 Tibetan males and 150 females have been analyzed. Whorls are more abundant in Tibetan males (60.24%) than in females (48.67%). The index of pattern intensity shows a higher value in males (15.95) than the females (14.65). The bimanual differences (both in males and females) are not statistically significant for the occurrence of pattern on the digits of the right and left hands. However, the difference between the sexes for the occurrence of patterns on the finger balls, are statistically significant. Ridge counting was done for each finger. On all fingers, Tibetan males have higher ridge-counts than females. The possible tendency for the right hands to possess higher ridge-counts cannot be demonstrated statistically. Tibetans show greater affinity with the Southern Mongoloids in the frequency distributions of pattern types on the finger balls. However, a more detailed dermatoglyphic study of all the Mongoloid populations in South East Asia, Central Asia and Far East would yield information of great value in disclosing the palmar pattern distributions among the Mongoloids.     

不同海拔地区高原鼠兔探究性和静止代谢率的差异

环境的差异影响动物种群生活史对策的进化。对地理分布范围广的物种而言,栖息地环境差异大,不同种群的生活史对策亦存在显著差异。个性特征作为生活史的一部分,反映了动物对环境的适应模式。前期研究表明,不同海拔区域的高原鼠兔的生活史对策存在显著差异,然而,其个性特征及与能量代谢的关联性是否也存在差异,目前尚不清楚。2018年9-10月,分别在海拔3268 m的贵南县和3980 m的玛沁县测定当地高原鼠兔的探究性与静止代谢率。结果发现,高海拔雄性高原鼠兔的探究性显著低于低海拔雄性个体;高海拔雌性高原鼠兔体重矫正静止代谢率显著高于低海拔雌性个体。高海拔地区,雌性高原鼠兔的探究性和体重矫正静止代谢率呈显著正相关,雄性高原鼠兔的探究性和体重呈显著负相关;低海拔地区,高原鼠兔的探究性和体重矫正静止代谢率或体重之间均无显著相关性。该结果 表明,调整个性特征和能量代谢及其两者的关联性也是高原鼠兔适应不同海拔栖息地环境差异的生活史对策之一。     

非优势顺位雄性黄山短尾猴的交配策略

在多雄多雌、顺位决定交配机会、雄性偏斜繁殖的非人灵长类社会中,低顺位雄性为提高自己的繁殖成功率,通常采取多样的交配策略以获得较多的交配机会。对非优势顺位雄性交配策略的研究可以增加对灵长类社会性行为复杂性的理解,对于深入探讨动物的婚配制度及繁殖策略具有十分重要的科学意义。本研究采用目 标动物取样法和全事件记录法,在２０１２ 年９ －１２ 月（交配期）记录了安徽黄山短尾猴鱼鳞坑ＹＡ１ 群中４ 只成年雄性个体的交配及有关的行为。研究发现：（１）非优势顺位雄性个体在远离优势顺位雄性视野范围的交配频次和交配时间显著高于优势顺位视野范围内;（２）与优势顺位雄性个体相比,非优势顺位雄性的强行交配（forced copulation）和隐秘交配（clandestine copulation）比例较高;（３） 就交配对象而言,对成功生育的雌性个体,优势顺位雄性在选择交配对象时具有明显的倾向性,非优势顺位雄性在选择时倾向性不显著;对未生育的雌性,优势顺位雄性更倾向于选择没有生殖经历的亚成年雌性个体,非优势顺位雄性则倾向于选择处于哺乳后期的成年雌性个体;（４）在具体交配策略上,优势顺位雄性选择跟随（follow） 雌性,非优势顺位雄性则通过做鬼脸 （grimacing）和性追求（sexual chasing）直接获取交配机会。本研究结果表明黄山短尾猴中非优势雄性个体形成了多变的交配策略,更多采取强制性方式,以获得更多的交配机会,多数的交配都是机会性的。