Genome-wide Analysis of Body Proportion Classifies Height-Associated Variants by Mechanism of Action and Implicates Genes Important for Skeletal Development

Human height is a composite measurement, reflecting the sum of leg, spine, and head lengths. Many common variants influence total height, but the effects of these or other variants on the components of height (body proportion) remain largely unknown. We studied sitting height ratio (SHR), the ratio of sitting height to total height, to identify such effects in 3,545 African Americans and 21,590 individuals of European ancestry. We found that SHR is heritable: 26% and 39% of the total variance of SHR can be explained by common variants in European and African Americans, respectively, and global European admixture is negatively correlated with SHR in African Americans (r² ≈ 0.03). Six regions reached genome-wide significance (p < 5 × 10⁻⁸) for association with SHR and overlapped biological candidate genes, including TBX2 and IGFBP3. We found that 130 of 670 height-associated variants are nominally associated (p < 0.05) with SHR, more than expected by chance (p = 5 × 10⁻⁴⁰). At these 130 loci, the height-increasing alleles are associated with either a decrease (71 loci) or increase (59 loci) in SHR, suggesting that different height loci disproportionally affect either leg length or spine/head length. Pathway analyses via DEPICT revealed that height loci affecting SHR, and especially those affecting leg length, show enrichment of different biological pathways (e.g., bone/cartilage/growth plate pathways) than do loci with no effect on SHR (e.g., embryonic development). These results highlight the value of using a pair of related but orthogonal phenotypes, in this case SHR with height, as a prism to dissect the biology underlying genetic associations in polygenic traits and diseases.     

"Lucy's" body height and relative leg length: human- or ape-like?

The body height of Australopithecus afarensis A.L. 288-1 ("Lucy") has recently been estimated and calculated as between 1 m to 1.06 m; other estimates give ca. 1.20 m. In addition, it is often stated that her relative leg length was shorter than that of modern humans. Using relative leg-, femur- and tibia length it is shown that both statements together can not be true; either her body height must at least have been around 1.06 to 1.10 m to give "Lucy" human-like leg proportions, or, to achieve a shorter, more ape-like leg ratio, a body height of ca. 1.20 m must be assumed.     

Some secular changes in body height and proportion of Japanese medical students

Anthropometric dimensions of 738 medical students at Kyushu University in Japan were analyzed to determine secular changes of height and body proportions during a 20-year period. Since 1961, means of standing height, leg length, and ratio of leg length to standing height have increased, although the rate of increase from 1971 to 1981 has been rather slow. On the contrary, the mean sitting height X 100/standing height has declined during this same period. Compared with data on the Japanese general population, the medical students were considerably taller, but the difference has decreased.     

Increased heterozygosity and child growth in an isolated subsistence agricultural community in the valley of Oaxaca, Mexico

Gene flow and rate of inbreeding (delta F) were calculated from demographic data for a community previously reported to be isolated from outside genetic influences of immigration. Significant child growth differences caused by gene flow among children born to native parents (n = 287) and offspring of native-immigrant matings (n = 38) were found in fatness (triceps skinfold), body proportions (sitting height ratio), and size (leg length). No differences were found between the two groups in height, weight, sitting height, and arm circumference. Variation in absolute and relative leg length in this population parallels previously reported differences in adult body size and proportion associated with increased heterozygosity caused by gene flow in other populations in southern Mexico.     

凡纳对虾形态性状对体重的影响效果分析

选择 6月龄凡纳对虾 176只 ,测定了体长、头胸甲长、胸宽、胸高、额剑上刺数、额剑下刺数、尾长和上市体重共 8个性状 ,采用相关分析和通径分析方法 ,剔除了与体长及头胸甲长有共线性的自变量尾长 ,计算了以形态性状为自变量对体重作依变量的相关系数、通径系数、决定系数及相关指数 ,定量地分析了形态性状对体重的影响效果。结果表明 ,凡纳对虾 5个形态性状与体重的相关系数达到极显著水平 (P<0 .0 1) ;通径分析揭示了多元分析中多个自变量与依变量的真实关系 ,体长、头胸甲长、胸宽、额剑下缘刺数目对体重的通经系数达到显著水平 ,它们是直接影响体重的重要指标 ,其中体长对体重的直接影响(0 .4 2 8* * )最大 ,是影响体重的最主要因素 ,其次为头胸甲长 (0 .2 90 * * )和胸宽 (0 .2 4 5 * * ) ,额剑下缘刺数对体重的直接影响(0 .0 70 * )较小 ;胸高与体重的相关程度很大 (0 .792 3) ,但它与额剑上缘刺数对体重的直接影响都非常小 ,主要通过其他性状间接影响活体重 ,是影响体重的次要因素 ,均被剔除 ;决定系数分析结果与通径分析结果有一致的变化趋势 ;所选形态性状与体重的复相关指数为 R2 =0 .92 13,说明影响体重的主要自变量指标已经找到 ;多元回归分析建立了体长 (X1 )、头胸甲长 (X2 )、胸宽(X3)、     

人体测量指标与掌指纹特征之间的相关研究

本文对106名中国东北汉族女性进行了活体测量,并拓取了掌指纹。样本的年龄范围为18—34岁。所分析的人体测量指标共41项,掌指纹指标共59项。将人体测量指标与掌指纹指标同时输入电子计算机,进行了100项实验指标间的相关分析,并做了相关显著性检验。在41项人体测量指标中,有35项指标与掌指纹特征有相关关系。其中与掌指纹特征同时相关的人体测量特征有18项,与指纹特征相关的人体测量指标有2项,与掌纹相关的人体测量指标有15项。与掌指纹特征同时相关的人体测量特征,与遗传因素之间的相互关系大于与指纹相关的人体测量特征。与指纹相关的人体测量特征,与遗传因素的关系,要大于与掌纹相关的人体测量特征。     

胸腰段骨折外科治疗的研究进展

胸腰椎骨折是骨科临床工作中常见的损伤。胸腰段骨折往往伴发不同程度的脊髓损伤,很大程度上影响患者的生活质量。准确把握其分型,并制定恰当、及时、有效的治疗方案,对伤员进行救治,恢复椎体的高度、序列与曲度,解除神经压迫,重建脊柱稳定性,减少近远期并发症,改善预后有着深远的意义。本文通过对胸腰段骨折的分类、手术入路、手术方式、不同类型骨折的治疗等四个方面的国内外近期研究成果作一综述。     

Physical anthropology: Human evolution. By Ivan G. Pawson. Wiley,New York. 1977. x + 246 pp., figures,tables, index. $4.95 (paper)

Growth is marked by changes in body shape as well as increase in body size. It is suggested that changes in body shape in childhood and adolescence be analyzed by least squares fit lines for one dimension on a second at successive ages. These are preferred during childhood to the traditional indices of anthropologists because body proportions change with growth, and one can identify the direction of the change and observe which body dimension is changing, or if both are. Furthermore, populations may be compared by analysis of covariance for different patterns of growth related to sex and ethnic groups. Analysis of a number of populations have demonstrated clear differences between the sexes and between populations for the following body proportions: sitting height to leg length, arm length to leg length, biacromial width to biiliac width.     

Effects of X chromosome on size and shape of body: an anthropometric investigation in 47,XXY males

The effects of an extra X chromosome on size and shape of body and head were studied in 47,XXY males; 25 anthropometric measurements were recorded from 29 adult 47,XXY males and compared with those of male relatives and control males. In stature, arm length, leg length, triceps skinfold, and subscapular skinfold 47,XXY males were larger and in biacromial diameter, bideltoid breadth, wrist breadth, and in most head dimensions smaller than normal males. Arm length was increased less than leg length. Increase in stature seemed to be caused solely by increased leg length, and the somewhat feminine proportions in trunk were caused by decrease in biacromial diameter. Correlations of the body and head dimensions between 47,XXY males and their male relatives were found to be normal. The present findings support the earlier proposals that X chromosome carries genes which influence linear growth. It is suggested that the reduction in biacromial diameter is caused by lowered plasma testosterone level which may also have affected sitting height. The control of body and head dimensions seems to be maintained relatively normal.     

The use of biocultural data in interpreting sex differences in body proportions among rural Amazonians

Variation in height and body proportions is relatively well-understood at the inter-population level, but less is known about intra-population variation. This study explores intra-population variation in body proportions among 172 (88 female; 84 male) adult rural Amazonians. We test the hypotheses that: (1) stunting is associated with changes in proportions and fatness; (2) the sexes express different proportions in response to similar environmental stress; and (3) female growth is negatively affected by the costs of reproduction. We examined height, sitting height, and total leg length in subsamples based on sex and nutritional status (stunted/nonstunted) in relation to biocultural factors including access to food and healthcare and female reproductive history parameters. Differences in proportions were examined using the Quick-Test (Tsutakawa and Hewett: Biometrics 33 (1977) 215-219); correlation analyses were used to detect associations between anthropometric data and body fatness, and female reproductive history parameters. We found significantly higher rates of stunting among females (X(2) = 5.31; P = 0.02; RR = 1.4). Stunted individuals exhibited relatively shorter legs than nonstunted individuals (P = 0.02), although this was not found in within-sex analyses. A significant negative correlation was found between leg length index and fatness (P < 0.01). Lastly, females exhibited relatively shorter legs than males (P = 0.0003) and, among females, height and leg length were significantly positively correlated with age-at-first-birth (P < 0.02) suggesting that adolescent pregnancy may negatively affect growth in this population. Our findings provide insights for the study of intra-population variation in body proportions and highlight the importance of biocultural data in interpreting the pattern of variation observed in living and past populations.     

The effect of leg position on knemometric measurements of lower leg length

Using the Valk knemometer, lower leg length (LLL) was assessed relative to changes in the positioning of the upper leg. Lowering the chair height of the knemometer resulted in a more acute angle between the upper and lower leg and a decrease in LLL. This decrease in measurement was attributed to changes in the anatomical surface of the knee underlying the measuring platform as a result of increasing the acuity of the leg angle. Based on four different leg positions, the average change in LLL per centimeter change in chair height was 0.607 mm in a child sample of 50, and 0.655 mm in an adult sample of 20. The difference in chair height with the leg angle at 90 degrees and the lowest chair height possible, ranged from 12.3 to 30.3 mm, relative to lower leg length. This meant the longest leg in the study had a LLL measurement differing by 19.8 mm between these two positions. Due to the effect of leg position, we advised the use of a standard method of measuring LLL with respect to leg angle. Given the difficulties in accurately measuring leg angle with current available tools, we advise the most acute angle.     

Secular change in growth of native children and adolescents at high altitude I. Puno,Peru (3800 meters)

A cross sectional sample of 969 native males from Puno (Peru), altitude 3800 m, ranging in age from 7–20 years, and studied for body height, weight, sitting height, leg length, and chest circumference in 1980, were compared, from the point of view of secular trend, with another cross sectional sample of 992 native males from the same place, which were investigated in 1945. In addition, similar observations were carried out in 1980, in a group of 112 females. The data indicate that in Puno there has been no secular increment in the adult body size. However for all ages between 7 and 19 years, body weight and height were significantly greater in 1980 than in 1945. This may be due to earlier sexual maturation in the present generation.     

Relationships between legs bone mineral density, anthropometry and jumping height in prepubertal children

The aim of this study was to determine how the legs bone mineral density (BMD) is influenced by anthropometry and vertical jumping height in prepubertal children. In total, 64 8-11-year-old schoolchildren (27 boys and 37 girls) were studied. All children were at Tanner stage 1. The subjects' height and body mass were measured and BMI calculated. The following anthropometric parameters directly connected with leg were measured: skinfolds--front thigh and medial calf girths--gluteal, thigh, mid-thigh, calf and ankle; lengths--iliospinale height, trochanterion height, trochanteriontibiale laterale, tibiale-laterale height and tibiale mediale-spyrion tibiale; and breadths--biiliocristal, foot length and biepicondylar femur. Total body and legs fat mass and fat %, lean body mass (LBM) and both legs BMD were measured by DXA. Maximal jumping height was measured on the contact mat. Stepwise multiple regression analysis indicated that body height in boys (54.6%; R2 x 100) and body mass in girls (57.3%) were the most important basic anthropometric parameters that influenced BMD in legs. From the measured skinfolds, that of the front thigh characterized legs BMD by 24.9-35.6%. From the girths, the most important parameter to characterize legs BMD was that of calf (50.0-59.1%). Tibiale laterale height was the only length parameter which was highly related with legs BMD (51.1-54.5%). Biepicondylar femur was the most important breadth parameter which characterized legs BMD (51.0-54.8%). Femur breadth and tibiale-laterale height were selected (68.7%) in boys, and tibiale-laterale height and front thigh skinfold thickness (66.0%) in girls when all measured leg anthropometric parameters were analyzed together. From the body composition parameters, the most important parameter to characterize legs BMD was legs LBM (48.9-59.5%). Jumping height did not correlate with legs BMD in any studied groups. In summary, the present study demonstrated that legs LBM together with tibiale-laterale height are the main predictors of legs BMD in prepubertal children.     

Physical growth of St. Lawrence Island Eskimos: Body size,proportion, and composition

Growth patterns of body size, proportion, and composition were analyzed in 57 male and 56 female Eskimos from St. Lawrence Island in the Bering Sea, ranging in age from 1.23 through 19.82 years. Age-groups means for whites and blacks of the U.S. Health Examination Survey served as reference data. Relative to HES data, the Eskimo sample were shorter with lower values for leg length, while there were no differences from the reference values for sitting height. The Eskimos also had higher values of Quetelet's Index, the sitting height/height ratio, and the upper arm muscle circumference, while there were no differences in body weight or triceps skinfold thickness. Differences from the reference data were more pronounced in males than in females. The growth patterns for size and body proportion are in conformity with known relationships between morphology and climate.     

Assessment of body cell mass at bedside in critically ill patients

Critical illness affects body composition profoundly, especially body cell mass (BCM). BCM loss reflects lean tissue wasting and could be a nutritional marker in critically ill patients. However, BCM assessment with usual isotopic or tracer methods is impractical in intensive care units (ICUs). We aimed to modelize the BCM of critically ill patients using variables available at bedside. Fat-free mass (FFM), bone mineral (Mo), and extracellular water (ECW) of 49 critically ill patients were measured prospectively by dual-energy X-ray absorptiometry and multifrequency bioimpedance. BCM was estimated according to the four-compartment cellular level: BCM = FFM - (ECW/0.98) - (0.73 × Mo). Variables that might influence the BCM were assessed, and multivariable analysis using fractional polynomials was conducted to determine the relations between BCM and these data. Bootstrap resampling was then used to estimate the most stable model predicting BCM. BCM was 22.7 ± 5.4 kg. The most frequent model included height (cm), leg circumference (cm), weight shift (Δ) between ICU admission and body composition assessment (kg), and trunk length (cm) as a linear function: BCM (kg) = 0.266 × height + 0.287 × leg circumference + 0.305 × Δweight - 0.406 × trunk length - 13.52. The fraction of variance explained by this model (adjusted r(2)) was 46%. Including bioelectrical impedance analysis variables in the model did not improve BCM prediction. In summary, our results suggest that BCM can be estimated at bedside, with an error lower than ±20% in 90% subjects, on the basis of static (height, trunk length), less stable (leg circumference), and dynamic biometric variables (Δweight) for critically ill patients.     

胸腰段骨折外科治疗的研究进展

胸腰椎骨折是骨科临床工作中常见的损伤。胸腰段骨折往往伴发不同程度的脊髓损伤,很大程度上影响患者的生活质量。准确把握其分型,并制定恰当、及时、有效的治疗方案,对伤员进行救治,恢复椎体的高度、序列与曲度,解除神经压迫,重建脊柱稳定性,减少近远期并发症,改善预后有着深远的意义。本文通过对胸腰段骨折的分类、手术入路、手术方式、不同类型骨折的治疗等四个方面的国内外近期研究成果作一综述。     

Analysis of functional scoliosis by means of an anisotropic beam model of the human spine

An upright, muscle-relaxed human spine, suffering from a mild functional scoliosis, caused by a small difference in leg length, is modeled as an anisotropic, elastic beam. The lower end of the beam is built-in in a fixed body, i.e., the laterally tilted pelvis. The upper end is rigidly attached to a rigid body, i.e., the supported upper part of the trunk, which is supposed to move freely in the frontal plane. It is shown that the characteristic scoliotic curvature of the spine, observed on an X-ray picture, can be reproduced by means of buckling analysis of the beam model, using realistic values of geometric and loading parameters and a properly chosen bending stiffness, which is found to be in reasonable agreement with earlier experimental findings. The analysis also shows that the muscle-relaxed upright equilibrium position of the spine is mechanically unstable.     

Genetic and environmental effects on growth of children from a subsistence agricultural community in southern Mexico

Sibling correlations for size attained in height, weight, sitting height, estimated leg length, the triceps skinfold, arm circumference, and estimated midarm muscle circumference were compared in 6- through 13-year-old schoolchildren grouped by household socioeconomic status. The children were residents of a Zapotec-speaking, subsistence agricultural community in the Valley of Oaxaca in southern Mexico. Sibling pairs were classified as being from high and low socioeconomic status (SES) households, and sibling correlations were computed within each SES group controlling for environmental effects derived from a factor analysis of information on household demography and land and livestock holdings. Like-sex siblings from lower SES households have significantly different correlations in four instances. Correlations are higher for leg length in lower SES brothers and higher for sitting height and weight in lower SES sisters, while the correlation for sitting height is higher in upper SES brothers. The sibling correlation results are not entirely consistent with observations on growth status by SES, particularly if the power and similarity of a common environment is the only cause of higher sibling correlations. Reduced body size under poorer socioeconomic and presumably nutritional circumstances is apparent, but it is not possible in this analysis to distinguish whether genotypic (developmental) plasticity or genetic adaptation, or both, are involved.     

Sexual dimorphism in leg length among orb-weaving spiders: a possible role for sexual cannibalism

The degree and direction of sexual dimorphism across different species is commonly attributed to differences in the selection pressures acting on males and females. The extent of these differences is especially apparent in species that practise sexual cannibalism, where the female attempts to capture and eat a courting male. Here, we investigate the relationship between sexual dimorphism in size and leg length, sexual cannibalism and courtship behaviour in three taxonomic groups of orb-weaving spiders, using morphological data from 249 species in 36 genera. Females are larger than males in all three taxonomic groups, and males have relatively longer legs than females in both the Araneinae and Tetragnathidae. Across genera within each taxonomic group, male body size is positively correlated with both female body size and male leg length, and female body size is positively correlated with female leg length. Sexual size dimorphism is negatively correlated with relative male leg length within the Araneinae, but not within either the Tetragnathidae or the Gasteracanthinae. There was no negative correlation between sexual size dimorphism and relative female leg length in any taxonomic group. We argue that the relationship between sexual size dimorphism and relative male leg length within the Araneinae may be the result of selection imposed by sexual cannibalism by females.     

Predator‐induced spine length and exocuticle thickness in Leucorrhinia dubia (Insecta: Odonata): a simple physiological trade‐off?

1. Morphological defence structures evolve against predators but are costly to the individual, and are induced only when required. A well‐studied example is the development of longer abdominal spines in dragonfly larvae in the presence of fish. Numerous attempts to discover trade‐offs between spine size and behaviour, development time or body size have, however, produced little evidence. 2. We considered a physiological trade‐off. Spines consist of cuticle and using material to build longer structures may result in less material remaining elsewhere. We therefore measured exocuticle thickness at nine locations on Leucorrhinia dubia larvae from habitats with and without fish. 3. Our results show a significant effect of the interaction between fish presence and spine length on head and fore leg exocuticle thickness. Relative thickness increased with relative length of lateral spine 9 in the absence of fish, whereas no such relationship existed with fish. Hence, synthesis and secretion of cuticle material occur as a trade‐off when larvae react to fish presence. 4. We assume the mechanism to be a selective synthesis of material with different responses in different parts of the larval body. These findings offer a new angle to the fish/spine trade off debate.