A QTL for genotype by sex interaction for anthropometric measurements in Alaskan Eskimos (GOCADAN Study) on chromosome 19q12-13

Variation in anthropometric measurements due to sexual dimorphism can be the result of genotype by sex interactions (G×S). The purpose of this study was to examine the sex-specific genetic architecture in anthropometric measurements in Alaskan Eskimos from the Genetics of Coronary Artery Disease in Alaska Natives (GOCADAN) study. Maximum likelihood-based variance components decomposition methods, implemented in SOLAR, were used for G×S analyses. Anthropometric measurements included BMI, waist circumference (WC), waist/height ratio, percent body fat (%BF), and subscapular and triceps skinfolds. Except for WC, mean values of all phenotypes were significantly different in men and women (P < 0.05). All anthropometric measures were significantly heritable (P < 0.001). In a preliminary analysis not allowing for G×S interaction, evidence of linkage was detected between markers D19S414 and D19S220 on chromosome 19 for WC (logarithm of odds (lod) = 3.5), %BF (lod = 1.7), BMI (lod = 2.4), waist/height ratio (lod = 2.5), subscapular (lod = 2.1), and triceps skinfolds (lod = 1.9). In subsequent analyses which allowed for G×S interaction, linkage was again found between these traits and the same two markers on chromosome 19 with significantly improved lod scores for: WC (lod = 4.5), %BF (lod = 3.8), BMI (lod = 3.5), waist/height ratio (lod = 3.2), subscapular (lod = 3.0), and triceps skinfolds (lod = 2.9). These results support the evidence of a G×S interaction in the expression of genetic effects resulting in sexual dimorphism in anthropometric phenotypes and identify the chromosome 19q12-13 region as important for adiposity-related traits in Alaskan Eskimos.     

Truncal and Abdominal Fat as Determinants of High Triglycerides and Low HDL‐cholesterol in Adolescents

We examined whether abdominal and truncal adiposity, assessed with simple anthropometric indices, determines serum triglycerides and high‐density lipoprotein (HDL)–cholesterol levels independently of total adiposity amount in adolescents. A total of 547 Spanish adolescents (284 males and 263 females) aged 13–18.5 years were included in this study. Measures of truncal adiposity included subscapular to triceps ratio, and trunk‐to‐total skinfolds ratio (TTS%). Waist circumference was used as a surrogate of abdominal adiposity, and BMI was used as a measure of total adiposity. The results of the regression models indicated that levels of triglycerides were positively associated with waist circumference and TTS% after controlling for age and Tanner stage in both sexes. Once BMI was entered in the model, these associations remained significant for waist circumference in females. HDL‐cholesterol levels were negatively associated with waist circumference in both sexes, and with subscapular to triceps ratio and TTS% in males, after controlling for age and Tanner stage. Once BMI was entered in the model, these associations remained significant for subscapular to triceps ratio and for TTS% in males. The results of this study suggest that in male adolescents, truncal adiposity is negatively associated with levels of HDL‐cholesterol, whereas in females, abdominal adiposity is positively associated with levels of triglycerides independently of total adiposity. These findings highlight the deleterious effect of both truncal and abdominal fat depots on the lipid profile already from the first decades of life.     

Seasonal variation and sex differences in the nutritional status in two local populations of wild Japanese macaques

Seasonal variations and sex differences in the nutritional status in two local populations of wild Japanese macaques (Macaca fuscata fuscata) were examined. It was hypothesized that the ecological condition and/or reproductive strategies of each sex determine the nutritional condition and its seasonal fluctuation in each sex. Morphometric measures such as body mass, thoracic and femoris circumferences, skinfold thickness in four places (triceps, biceps femoris, subscapular, and abdomen), and wet mass of mesenteric and omental fat were used for comparisons between sexes, seasons, and populations. Animals of the Shimane population were larger than those of the Boso population in most morphometric measures, abdominal skinfold, and mesenteric and omental fat mass, suggesting environmental and/or genetic differences in the two populations. Females of both populations had larger skinfolds and mesenteric and omental fat mass than males, indicating that females had more fat than males. Females showed seasonality in most measures, having two peaks of body mass, thoracic and femoris circumferences, abdominal skinfold, and mesenteric and omental fat masses in early spring and late fall. In contrast, males exhibited no clear seasonal variations for most measurements, except for biceps femoris and subscapular skinfolds, which showed peaks in summer. Most morphometric measurements significantly correlated to each other, particularly in females, but most skinfolds had no correlation with other measurements. These findings suggest that sexual dimorphism in body composition and its fluctuation may be affected by the different reproductive strategies of males and females.     

达斡尔族成人的皮褶厚度及其年龄变化

测量了456例（男216,女240例）达斡尔族成人的4项皮褶（三头肌皮褶、肩胛下皮褶、髂前上棘皮褶与腓肠肌皮褶）厚度值,分析了达斡尔族成人皮褶厚度随年龄变化的特征。研究表明：（1）男性躯干皮下脂肪厚于四肢。女性肩胛下皮褶最厚,三头肌皮褶次之。（2）女性4项皮褶厚度值高于男性。（3）男性30—44岁皮下脂肪较厚,45岁以后皮褶厚度下降。女性50岁以后肩胛下皮褶值明显下降,其余3项值在40岁以后下降。（4）男性全身皮褶厚度值多呈正相关。女性这种现象不明显。（5）达斡尔族成人皮下脂肪发育逊于北京、大连城市中的汉族,但优于宁夏农村的回族。     

Fetal and infant head circumference sexual dimorphism in primates

Studies have shown that after controlling for the effects of body size on brain size, the brains of adult humans, rhesus monkeys, and chimpanzees differ in relative size, where males have a greater volume of cerebral tissue than females. We assess whether head circumference sexual dimorphism is present during early development by evaluating sex differences in relative head circumference in living fetuses and infants within the first year of life. Head circumference is used as a proxy for brain size in the fetus and infant. Femur length is used as a proxy for body length in the fetus. Ultrasonography was used to obtain fetal measures, and anthropometry was used to obtain postnatal measures in humans, rhesus monkeys, baboons, and common marmosets. We show that statistically significant but low levels of head circumference sexual dimorphism are present in humans, rhesus monkeys, and baboons in early life. On average, males have head circumferences about 2% larger than females of comparable femur/body length in humans, rhesus monkeys, and baboons. No evidence for head circumference sexual dimorphism in the common marmoset was found. Dimorphism was present across all body size ranges. We suggest that head circumference sexual dimorphism emerges largely postnatally and increases throughout maturation, particularly in humans who reach adult dimorphism values greater than the monkeys. We suggest that brain dimorphism is not likely to impose an additional energetic burden to the gestating or lactating mother. Finally, some of the problems with ascribing functional significance to brain size sexual dimorphism are discussed, and the energetic implications for brain size sexual dimorphism in infancy are assessed.     

Growth pattern of the Kamars--a primitive tribe of Chhattisgarh,India

A cross sectional study of the physical growth status was made on 655 Kamar children (341 boys and 314 girls), aged 5 to 18 years, in the Raipur district of Chhattisgarh. The study aimed to find out the growth pattern of the Kamar children, which is considered to be a primitive tribe of Chhattisgarh, India and was compared with another Indian tribe and the official data for all India (ICMR). Anthropometric measurements included height, weight, sitting height, biacromial diameter, biilliocrystal diameter, upper arm circumference, calf circumference and measurements of the triceps and subscapular skinfolds. All anthropometric measurements except skinfold thickness exhibit uniform increase with age in both sexes. However, when height and weight of the Kamar boys and girls were compared with the data for other tribes and for all India, the Kamar children (both boys and girls) indicated lower weight and height and the difference showed to be significant, for almost all ages. Kamar boys showed higher anthropometric values than girls in almost all measurements except in biilliocrystal diameter and in measured skinfolds. Poor socio-economic status of this primitive tribe may be one of the reasons for this poor growth pattern. However, in-depth study is necessary in order to arrive at any basic conclusions and to recommend any policy and interventions.     

Anthropometric data in middle-aged women. The population study of women in G?teborg 1968-1969.

Body weight, body height, skinfolds, circumferences and weight indices in a population sample of 1462 women in ages between 38 and 60 years are presented. Significant age differences were noted. High correlations (r) were found between body weight and triceps and subscapular skinfolds (0.62 and 0.72 respectively) and between body weight and arm, waist and buttock circumferences (0.75-0.88). Age differences were mostly noted between 46 and 50 years of age. After that age there was a comparatively greater increase of the waist circumference than of the buttock circumference, while triceps skinfold seemed to decrease after the age of 50 indicating an altered adipose tissue distribution from the extremities to the trunk with increasing age. When taking data from a previous study of body weight in the same population of women into consideration it seems that the age differences in body weight found in cross-sectional study like the present one may to a large extent depend on differences between different cohorts studied.     

Waist Circumference and Cardiovascular Risk Factors in Prepubertal Children

Objective: Intra‐abdominal fat has been identified as being the most clinically relevant type of fat in humans. Therefore, an assessment of body‐fat distribution could possibly identify subjects with the highest risk of adverse lipid profile and hypertension. Few data on the relationship between body‐fat distribution and cardiovascular risk factors are available in children, especially before puberty. Research Methods and Procedures: This cross‐sectional study was undertaken to explore the relationship between anthropometric variables, lipid concentrations, and blood pressure (BP) in a sample of 818 prepubertal children (ages 3 to 11 years) and to assess the clinical relevance of waist circumference in identifying prepubertal children with higher cardiovascular risk. Height, weight, triceps and subscapular skinfolds, waist circumference, and BP were measured. Plasma levels for triacylglycerol, total cholesterol, high‐density lipoprotein (HDL) cholesterol, low‐density lipoprotein cholesterol, apolipoprotein A1 (ApoA1), and apolipoprotein B (ApoB) were determined. Results: Females were fatter than males (5.8 [3.5] vs. 4.8 [3.3] kg of fat mass; p < 0.01). Males had higher HDL cholesterol and ApoA1/ApoB plasma concentrations than females (p < 0.001 and p < 0.01, respectively). Waist circumference had a higher correlation with systolic and diastolic BP (r = 0.40 and 0.29, respectively; p < 0.001) than triceps (r = 0.35 and 0.21, respectively; p < 0.001) and subscapular (r = 0.28 and 0.16, respectively; p < 0.001) skinfolds and relative body weight (0.33 and 0.23, respectively; p < 0.001). Multivariate linear model analysis showed that ApoA1/ApoB, HDL cholesterol, total cholesterol/HDL cholesterol, and systolic as well as diastolic BP were significantly associated with waist circumference and triceps and subscapular skinfolds, independently of age, gender, and body mass index. Discussion: Waist circumference as well as subscapular and triceps skinfolds may be helpful parameters in identifying prepubertal children with an adverse blood‐lipids profile and hypertension. However, waist circumference, which is easy to measure and more easily reproducible than skinfolds, may be considered in clinical practice. Children with a waist circumference greater than the 90th percentile are more likely to have multiple risk factors than children with a waist circumference that is less than or equal to the 90th percentile.     

Nutritional status in two Mbyá-Guaraní communities from Misiones (Argentina)

Growth and nutritional status of children and adults in two Mbyá-Guaraní communities from Argentina, was assessed. Height, weight, sitting height, upper arm circumference, triceps and subscapular skinfold were measured on 120 individuals aged from 2 to 60 between March and May, 2001. Data were transformed to z-scores using United States references (NHANES I and NHANES II). A z-score of less than -2 was used as the cut-off point to determine the prevalence of stunting and wasting respectively. Mean z-scores for weight, height, and upper arm circumference lie below the reference (0 > Z > -3), while in sitting height ratio and muscular area for females they were above the US standard (0 < Z < 2). Skinfold thicknesses and muscular area for males were similar to the reference (2 > Z > -1). Our findings are in agreement with others South American Indian research that the prevalence of stunting (36.7%) is significantly higher than wasting (1.8%). The presence of parasitic infections and nutritional environment previously described in this population could be related to the short stature.     

中国石龙子个体发育过程中头部两性异型和食性的变化

许多动物呈现个体大小、局部形态特征 (头部大小 )和体色的两性异形[5,14 ,15,2 1,2 2 ] 。 Darwin[12 ] 认为两性谋求各自最大的繁殖利益导致了两性异形 ,因此两性异形是性选择压力作用的结果。自 Darwin以来 ,许多同行认为性选择压力和非性选择压力均能导致动物的两性异形 ,两种选择压力在不同的动物中所起的作用是不同的 [2～ 5,7,10 ,16,2 1～ 2 6] 。性选择压力导致的两性异形与繁殖成功率直接有关。非性选择压力导致的两性异形与繁殖成功率无关或无直接的关系 ,如两性寿命的差异 [13 ]、两性食性的分离 [6,2 1]和两性分配用于生长的…     

Using photogrammetry and color scoring to assess sexual dimorphism in wild western gorillas (Gorilla gorilla)

Investigating sexual dimorphism is important for our understanding of its influence on reproductive strategies including male-male competition, mate choice, and sexual conflict. Measuring physical traits in wild animals can be logistically challenging and disruptive for the animals. Therefore body size and ornament variation in wild primates have rarely been quantified. Gorillas are amongst the most sexually dimorphic and dichromatic primates. Adult males (silverbacks) possess a prominent sagittal crest, a pad of fibrous and fatty tissue on top of the head, have red crest coloration, their saddle appears silver, and they possess a silverline along their stomach. Here we measure levels of sexual dimorphism and within-male variation of body length, head size, and sexual dichromatism in a population of wild western gorillas using photogrammetry. Digital photogrammetry is a useful and precise method to measure sexual dimorphism in physical traits yielding sexual dimorphism indices (ISD), similar to those derived from traditional measurements of skeletal remains. Silverbacks were on an average 1.23 times longer in body length than adult females. Sexual dimorphism of head size was highest in measures of crest size (max ISD: 60.4) compared with measures of facial height (max ISD: 24.7). The most sexually dimorphic head size measures also showed the highest within-sex variation. We found no clear sex differences in crest coloration but there was large sexual dichromatism with high within-male variation in saddle coloration and silverline size. Further studies should examine if these sexually dimorphic traits are honest signals of competitive ability and confer an advantage in reproductive success.     

Sexual dimorphism in lizard body shape: the roles of sexual selection and fecundity selection

Sexual dimorphism is widespread in lizards, with the most consistently dimorphic traits being head size (males have larger heads) and trunk length (the distance between the front and hind legs is greater in females). These dimorphisms have generally been interpreted as follows: (1) large heads in males evolve through male-male rivalry (sexual selection); and (2) larger interlimb lengths in females provide space for more eggs (fecundity selection). In an Australian lizard (the snow skink, Niveoscincus microlepidotus), we found no evidence for ongoing selection on head size. Trunk length, however, was under positive fecundity selection in females and under negative sexual selection in males. Thus, fecundity selection and sexual selection work in concert to drive the evolution of sexual dimorphism in trunk length in snow skinks.     

Directional asymmetry of body dimensions among white adolescents

Asymmetry of paired dimensions has been recognized as a methodological problem in anthropometry and more recently as an indicator of environmental stress. This study seeks to determine the extent of directional asymmetry for some of the measurements commonly made in anthropometry. Upper arm circumference, biepicondylar breadth, triceps and subscapular skinfolds, bicondylar breadth of the femur, and calf circumference were measured on right and left sides among 135 white adolescents from suburban Philadelphia. Handedness (right or nonright) was subject-assessed. Body composition was estimated through underwater weighing. Asymmetry was evaluated using a paired t test. Arm measurements are significantly asymmetric in favor of the right side; subscapular skinfolds and leg measurements are not significantly asymmetric. Among the sample of right-handed subjects (n = 116), upper arm circumference and biepicondylar breadth were significantly larger on the right side, and, among the males of this subsample, triceps was as well. The nonright-handed subjects (n = 19) did not show statistically significant asymmetry. Asymmetry was negatively but weakly related to body composition. These results are consistent with an explanation in terms of preferred use of one side of the body and consequent muscle hypertrophy, but an adequate test of this explanation requires hypothesis testing in larger samples of nonright-handed subjects.     

Costal process of the first sacral vertebra: sexual dimorphism and obstetrical adaptation

The human sacrum is sexually dimorphic, with males being larger than females in most dimensions. Previous studies, though, suggest that females may have a longer costal process of the first sacral vertebra (S1) than males. However, these studies neither quantified nor tested statistically the costal process of S1. This study compares S1 with the five lumbar vertebrae (L1 to L5) for a number of metric dimensions, including costal process length. Four issues are addressed, the: 1) hypothesis that females have a longer costal process of S1 than males; 2)hypothesis that homologous structures (i.e., costal processes of L1 to S1) differ in their direction of sexual dimorphism; 3) importance of the costal process of S1 to the obstetrical capacity of the pelvis; and 4) evolution of sexual dimorphism in costal process length of S1. One hundred ninety-seven individuals, including males and females of American blacks and whites, from the Hamann-Todd and Terry Collections were studied. Results show that males are significantly larger than females for most vertebral measurements, except that females have a significantly longer costal process of S1 than males. Costal process length of S1 is positively correlated with the transverse diameter and circumference of the pelvic inlet. The magnitude of sexual dimorphism in costal process length of S1 ranks this measure among the most highly dimorphic of the pelvis. Compared with the humans in this study, australopithecines have a relatively long costal process of S1, but their broad sacrum was not associated with obstetrical imperatives.     

Anthropometric studies in Brazilian Cayapo Indians

Results of 16 measurements and 7 indices obtained from 130 men and 156 women belonging to three populations of Brazilian Indians are reported. For both males and females the averages for stature and head breadth are in the middle of the distribution range of values observed in other South American tribes; those for head length and nasal height are relatively low but the averages for sitting height, calf circumference and minimum frontal breadth are high. As for the indices, in both sexes the cephalic and cephalofacial are medium, the Rohrer, jugomandibularis and facial low, and the nasal high when compared with other tribes. Morphological distances between the three Cayapo populations were estimated using Mahalanobis' D² statistic; they are smaller than those separating different tribes and are not the expected ones when the demographic variables of these groups and the geographic distances between them are considered. The amount of variability as expressed by the coefficient of variation and the prevailing pattern of sexual dimorphism are similar to those observed in other Indian populations.     

Female choice, male interference, and sperm precedence in the red-spotted newt

Darwin first identified female choice and male—male competitionas forms of sexual selection resulting in the evolution of conspicuoussexual dimorphism, but it has proven challenging to separatetheir effects. Their effects on sexual selection become evenmore complicated when sperm competition occurs because spermprecedence may be either a form of cryptic female choice ora form of male—male competition. We examined the effectsof tail height on male—male competition and female choiceusing the sexually dimorphic red-spotted newt (Notophthalmusviridescens viridescens). Experiment 1 examined whether maletail height influenced male mating success. Males with deeptails were more successful at mating with females than thosewith shallow tails. Successful, deep-tailed males also were bigger(snout-vent length; SVL) than unsuccessful, shallow-tailed males,but they did not vary in tail length or body condition. Of these,only tail height and tail length are sexually dimorphic traits.Experiment 2 tested the hypothesis that the differential successof males with deeper tails was due to female choice by examiningboth simultaneous female preference for association and sequentialfemale choice. We found no evidence of female choice. When maleswere not competing to mate with females, tail height did notinfluence male mating success. Successful males did not havedifferent SVL and tail lengths than unsuccessful males. Thus,tail height in male red-spotted newts appears to be an intrasexuallyselected secondary sexual characteristic. Experiment 3 usedpaternity exclusion analyses based on molecular genetic markersto examine the effect of sperm precedence on sperm competitionin doubly-mated females. Sperm precedence likely does not havea pervasive and consistent effect on fertilization success becausewe found evidence of first, last, and mixed sperm usage.     

Growth and malnutrition of rural Zimbabwean children (6-17 years of age)

The rural environment is an important factor in delayed growth in developing countries. The aim of this study was to investigate the effects of poor rural living conditions on the growth of a Shona sample in Zimbabwe. In total, 982 subjects aged 6-17 years were analyzed. Mean values of height, weight, skinfolds (triceps, subscapular, suprailiac, biceps, medial calf), cormic index, body mass index (BMI), arm composition (total upper arm area, upper arm muscle area, arm fat area, and arm fat index), fat percentage (%F), centripetal fat ratio (CFR), and the contribution of each skinfold to the adiposity of the trunk and upper limbs are presented. Weight, height, BMI, cormic index, SSCP, TRCP, arm circumference, and arm composition are compared with NHANES percentiles. Boys and girls showed stunting and underweight at ages 11-15 and 8-15, respectively; boys presented particularly severe malnutrition and their means of height and weight were below the 10th percentile. The means of arm circumference, UMA, UFA, and TRCP were below the 15th percentile in both sexes. The contribution of the skinfolds generally showed an overall prevalence of TRCP in both sexes; the contribution of SSCP was prevalent only for the 16- to 17-year-old boys. Males presented a higher CFR than girls after 14 years while females showed an irregular pattern. There was a high incidence of brachycormia and mesocormia in females and males, respectively. Height, weight, and BMI were similar to the values observed in other sub-Saharan countries, although body size was slightly larger than in South Africa and smaller than in Tanzania. The results provide a useful database for future comparisons.     

Head shape allometry and proximate causes of head sexual dimorphism in Podarcis lizards: joining linear and geometric morphometrics

Podarcis bocagei and Podarcis carbonelli are two lacertid species endemic to the western Iberian Peninsula, and both show head size and shape sexual dimorphism. We studied immature and adult head sexual dimorphism and analysed ontogenetic trajectories of head traits with body and head size, aiming to shed light on the proximate mechanisms involved. Immatures were much less dimorphic than adults, but geometric morphometric techniques revealed that head shape sexual differences are already present at this stage. Males and females differed in allometry of all head characters with body size, with males showing a disproportionate increase of head size and dimensions. On the other hand, head dimensions and head shape changed with increasing head size following similar trends in both sexes, possibly indicating developmental restrictions. Consequently, adult sexual dimorphism for head characters in these species is the result of both shape differences in the immature stage and hypermetric growth of the head in relation to body size in males.  © 2008 The Linnean Society of London, Biological Journal of the Linnean Society , 2008, 93 , 111–124.     

Skinfold thicknesses in a national probability sample of U.S. males and females aged 6 through 17 years

Cycles II and III of the Health Examination Survey included measurements of the skinfolds of over 14,000 individuals 6 through 17 years of age, statistically weighted to provide an accurate national probability sample. Analyses of the triceps and subscapular skinfolds of Negroes and whites are reported here, utilizing the median in preference to the mean. Females of either racial group have thicker skinfolds at all ages studied. Whites have greater median triceps thicknesses than Negroes of the same sex and age, but there are no differences between the two racial groups in the subscapular. Since, between all but one pair of adjacent ages in males, from 12 years on, the median triceps fold decreases, but the estimated cross-sectional are of fat increases, it is strongly recommended that reductions in triceps thickness not be automatically interpreted as meaning a loss of subcutaneous fat. Since greater skewness is found in the subscapular distributions in whites, but not in the triceps, it is suggested that racial differences in triceps thickness at these ages occurs from the operation of hereditary factors, while differences in the subscapular skinfold arise from environmental causes.     

Childhood malnutrition and growth in a rural area of Western Kenya

An anthropometric survey was carried out on 1,383 school students aged 5-17 years in Suba district (a rural area of western Kenya). Body size and proportion were computed from height, weight, sitting height, arm circumference, and skinfolds. The aim of the study was to evaluate patterns of growth and nutritional status of the Luo population by assessment of the prevalence and trends of malnutrition among children and adolescents. Very few age-groups show significant sex differences for height, body weight, and arm muscle area. However, there are several differences in skinfold thicknesses and arm circumference, always with higher mean values in girls. Analysis of the nutritional status (weight-for-age, height-for-age, and BMI-for-age) shows significant differences among the age-groups in both sexes. Boys present lower Z-scores than girls and there are higher percentages of malnourished subjects (stunted and underweight) among the males. The Luo data were compared with those of other African populations. Their body dimensions, nutritional status, and growth are similar to those of the other sub-Saharan samples. In conclusion, the Luo children are generally undernourished at the older ages: adolescents (11-16 years of age) show the most severe undernutrition and the highest percentages of undernourished subjects. In addition to the higher risk of undernutrition in teenagers, an emerging problem of over-nutrition is evident among the younger age-groups, with a higher prevalence in females. These findings are discussed in light of sexual dimorphism in sensitivity to adverse environmental conditions.