Genetic substructure analysis of three isolated populations in southwest China.

Southwest China is home to numerous ethnic minorities, as well as many geographically and genetically isolated groups. However, the genetic substructure of these ethnic groups, especially the paternal genetic structure between groups, has not been comprehensively analyzed. In this study, we used Y chromosome capture and Illumina sequencing technologies to investigate the paternal genetic structure of three isolated groups of male unrelated individuals, including Baima in Pingwu, Sichuan Province, Muya in Shimian, Sichuan Province, and Kongge in Jinghong, Yunnan Province. We calculated the frequencies of related haplogroups by the fixed-point compound amplification method and direct counting method, and used the Past3.0 software to perform principal component analysis to draw a population clustering tree. we observed that Kongge had 3 Y chromosome haplogroups, Baima had 4 Y chromosome haplogroups, and Muya had 5 Y chromosome haplogroups. The results showed that Kongge was most closely related to the Wa, and the Y chromosome types of the Baima and Muya were mainly concentrated in the D haplogroup and its lower reaches. It has the closest relationship with the Tibetans in Qamdo and Nyingchi. The study on the genetic structure of different ethnic groups has enriched the genetic relationship of isolated populations and provided a new perspective for understanding Chinese ethnic groups.

Estimation of stature by using the dimensions of the right hand and right foot in Han Chinese adults.

The Han Chinese people are the main ethnic group in China and the largest ethnic group in the world. The dimensions of the hands and feet have been successfully used for the estimation of stature. A total of 26,927 healthy adult subjects, comprising 13,221 men and 13,706 women, were recruited. The survey samples were chosen through random cluster sampling. The mean values were significantly higher in men than those in women for all measurements (P<0.001). All the measurements showed a statistically significant correlation with stature (P<0.01). The combination of the right hand length and the right foot length was the best predictor of stature because it had the lowest standard error of estimate. The use of multiple regression equations yielded better results than did the use of linear regression equations. The accuracy of stature prediction ranged from ±4.81 to ±6.39 cm. The present study was of great importance with regards to improving the physical anthropology database of ethnic groups in China.

Area-level socioeconomic disparities impact adult overweight and obesity risks of Han ethnicity in China.

OBJECTIVES: The profound socioeconomic processes occurring in developing countries have been accompanied by the notable increase of overweight and obese populations. This study for the first time investigates the impact of area-based socioeconomic status (SES) on adult overweight and obesity for both sexes of Han ethnicity in China. METHODS: We investigated 6,221 adult participants of Han ethnicity from 18 geographic areas in China, and measured stature and weight for each participant. The mean annual income per individual was chosen as the area-level SES index. We adopted logistic regression analysis to explore the relationship of area-level SES with overweight and obesity. RESULTS: The age-adjusted overweight and obesity prevalence was 32.46% for men and 29.27% for women respectively. Substantial area-level SES disparity in overweight and obesity risks for both sexes exist in China. The overweight and obesity prevalence rates increased with increasing SES levels in men rather than in women. CONCLUSION: Men living in high SES areas as well as women living at the lowest SES areas were most likely to be at the highest risk of overweight and obesity in China.

Ethnic inequalities and sex differences in body mass index among tibet minorities in China: implication for overweight and obesity risks.

OBJECTIVES: In the present study, we for the first time investigated overweight and obesity level among Tibet minorities (Deng, Lhoba, Monba) living in remote villages at the south slope of Qinghai-Tibetan Plateau, China. For each ethnicity, the total number of population is less than 10 thousands in China. METHODS: Anthropometric measurements were conducted on adult participants of three ethnicities in Tibet, China. Totally, the whole sample consists of 141 males and 163 females. Body mass index (BMI) was adopted to evaluate the overweight and obesity level. RESULTS: Within each ethnicity, there was no significant sex difference on BMI. The general prevalence of overweight and obesity level of Lhoba ethnicity (18.42%) is higher than that of Monba (17.65%) and Deng ethnicity (6.29%). For each sex, the distribution of BMI classification was found to be significantly associated with ethnicity identity. CONCLUSION: One possible reason for ethnic disparity among Tibet minorities in the present study is special dietary elements. Measures to prevent and cope with the problem of overweight and obesity among Tibet minorities are urgently required.

Digit ratio (2D:4D) and handgrip strength in Hani ethnicity.

INTRODUCTION: The ratio of the length of the second finger to the fourth finger (2D:4D) in humans is considered as a putative marker of prenatal exposure to testosterone, and has been progressively adopted as one useful tool to evaluate the effect of prenatal hormones in some traits such as physical ability. Handgrip strength is one authentic measure of physical ability and is generally used on the anthropological research within an evolutionary viewpoint. METHODS: Here we present the first evidence on 2D:4D and handgrip strength on adult participants of Hani ethnicity and explore the relationship between digit ratio (2D:4D) and handgrip strength. We examined 2D:4D and handgrip strength of 80 males and 60 females at Bubeng village, in the Yunnan province of China. RESULTS: The mean 2D:4D in females was higher than that in males for each hand. Females showed significantly higher 2D:4D than males in the right hand rather than in the left hand. Males displayed significantly higher handgrip strength than females for both hands. Handgrip strength decreased with age for both sexes. A significant negative correlation between 2D:4D and handgrip strength was found in the right hand of males. CONCLUSION: The relationship between 2D:4D and handgrip strength may be attributed to evolutionary drive of sexual selection operating on fetal programming.

Brief communication: Body mass index, body adiposity index, and percent body fat in Asians.

Human obesity is a growing epidemic throughout the world. Body mass index (BMI) is commonly used as a good indicator of obesity. Body adiposity index (BAI = hip circumference (cm)/stature (m)(1.5) - 18), as a new surrogate measure, has been proposed recently as an alternative to BMI. This study, for the first time, compares BMI and BAI for predicting percent body fat (PBF; estimated from skinfolds) in a sample of 302 Buryat adults (148 men and 154 women) living in China. The BMI and BAI were strongly correlated with PBF in both men and women. The correlation coefficient between BMI and PBF was higher than that between BAI and PBF for both sexes. For the linear regression analysis, BMI better predicted PBF in both men and women; the variation around the regression lines for each sex was greater for BAI comparisons. For the receiver operating characteristic (ROC) analysis, the area under the ROC curve for BMI was higher than that for BAI for each sex, which suggests that the discriminatory capacity of the BMI is higher than the one of BAI. Taken together, we conclude that BMI is a more reliable indicator of PBF derived from skinfold thickness in adult Buryats.

Physical characteristics of Chinese Hakka.

Using standard and internationally validated methods, 86 anthropologic characteristics were determined in 650 male (305 from urban areas and 345 from rural areas) and 704 female (331 from urban areas, 373 from rural areas) Chinese Hakka adults living in Guangdong and Jiangxi. The data were used to calculate 24 anthropologic indices, which were analyzed statistically. The physical characteristics of Hakka subjects were analyzed and compared with reference ethnic data. There were four main findings of this study. First, a small proportion of Hakka adults had an eye fold on the upper eyelid, but a large proportion had a mongoloid fold. The eye slits were narrow in most adults, had a medium nasal root height and straight bridges, and most of the external angles were prominent. The nasal base was upturned in most men. The distributions of the three types of nasal base in women were similar. The proportions of subjects with middle and high alae nasi heights were high and similar. Males with a maximum nostril diameter were mostly classified as transverse and oblique, while many women were classified as transverse and had relatively wide alae nasi. The round lobe type was the most common. Upper lip skin height was mostly classified as medium. Lips were classified as thin. The hair was black, eyes were brown, and the skin was yellowish. Second, the head length was long in male Hakka. The minimum frontal breadth, face breadth, lip height, and interocular breadth were similar to those of North-Asian populations. Meanwhile, head breadth, morphological facial height, nose breadth, mouth breadth, and nose height were similar to those of South-Asian populations. Head length was long in female Hakka. The minimum frontal breadth, face breadth, lip height, and interocular breadth were similar to those of North-Asian populations. Head breadth, nose breadth, and mouth breadth were similar to those of South-Asian populations. Third, the stature of male and female Hakka in urban and rural areas was classified as medium. The proportions of male and female Hakka classified as mesocephaly (length-breadth index of the head), hypsicephalic type, metriocephalic type (breadth-height index of the head) mesorrhiny, long trunk, subbrachyskelic type, broad shoulder breadth, and narrow distance between iliac crests were higher than those of other types. Finally, principal component analyses showed that the physical characteristics of Hakka were between those of South-Asian and North-Asian ethnic populations, but were generally closer to those of North-Asian populations in China.

Digit ratio (2D:4D) and handgrip strength in subjects of Han ethnicity: impact of sex and age.

The ratio of the length of the second finger to the fourth finger (2D:4D) is considered to be a putative proxy of prenatal exposure to testosterone, and has been increasingly used as a promising tool to evaluate the impact of prenatal androgenization in humans in such traits as physical performance. In this study, for the first time, we present 2D:4D data on adult participants of Han ethnicity. We consider the sexual dimorphism of 2D:4D and handgrip strength, and also report the relationship between 2D:4D and handgrip strength of males and females. The sample consisted of 54 males and 55 females recruited from a remote village in the Qinling Mountains, China. We found sexual dimorphism of both 2D:4D and handgrip strength, i.e., males had lower 2D:4D and right-left 2D:4D than females and greater handgrip strength than females. There was a sex-specific correlation between 2D:4D and handgrip strength, i.e., 2D:4D in the right hand was negatively correlated with handgrip strength in males but not in females. This relationship may be driven by sexual selection operating on fetal programming.

[Age variations of head-face morphological traits of Hakka in Guangdong province].

OBJECTIVE: To investigate the age variations of head-face morphological traits of Hakka in Guangdong Province. METHODS: Thirty-eight physical indices of head and face of 671 Hakka adults (151 urban males, 181 urban females, 162 rural males and 177 rural females) from Meizhou city of Guangdong were investigated. Twelve physical indices of head and face were calculated and counted its indices distributions. The age changes of morphological traits of head and face were analyzed. RESULTS: With the age growing, the rate of eyefold of the upper eyelid was increased, and the Mongoloid fold decreased, the direction of eyeslits tended to level, nasal root height dropped, the zygomatic projection was more projected, the eye color turned to lighter, the upper red lips became thinner; medium-sized facial height, nasal height, upper lip skin height, physiognomic ear length, physiognomic ear breadth and breadth of alae nasi were decreased. The index of mouth breadth, morphological facial skin fold were positively correlated with the age. The index of minimum frontal breadth, face breadth, bigonial diameter, interocular breadth, external biocular breadth, lip height, thickness of lips and horizontal head circumference were negatively correlated with the age. With the age growing, morphological facial index and vertical cephalo-facial index was ascending. Moreover, length-height index of head, transverse frontoparietal index, zygomatico-frontal index and lip index were declining. CONCLUSION: With the age growing, the head and face measurements, physical indices and the proportion of observed indices have changed in Hakka in Guangdong province.

[Study on 4 human population genetic characters of Mongol and Han in Western inner Mongolia].

From 1998 to 2001, a sample of 2760 Mongol and Han individuals was investigated in 3 areas (Eerduosi city, Xilinguole and Bayannaoer leagues) from Inner Mongolia. Each individual was studied on 4 genetic characters (thumb type, palmar digital formular, fingernail type and plantar digital formular). The result is as follows: (1) The frequencies of the straight thumb were over 60%, and there were no significant sexual differences in all of 6 groups. (2) The frequencies of the ring-finger-longer were much higher in 6 groups, and there were significant sexual differences in 4 groups. (3) The frequencies of the long-shaped fingernail were the highest in all groups, the squat-shaped were the lowest. (4) The big toes were longer than the second toes in most people of 6 groups,but without significant sexual differences in each groups. (5) There were no significant correlations between 4 characters.

[Studies of hereditary mode on three tongue moving types].

The data of 72 families were analyzed by the method of proband's sib and the method of segregation analysis. The results showed that the hereditary mode of rolling tongue or pointed tongue is the dominant heredity of single gene of autosome, and the positive type of them is the dominant character. Twisting tongue is the recessive heredity of single gene of autosome,while the positive type is the recessive character. Present study suggested, although environmental might affect these characters,hereditary factors seemed to be dominant.

Morphological traits in peoples of Mongolian nationality of the Hulunbuir league, Inner Mongolia, China.

A sample of 947 Mongolians of Bargud, Elute and Buriat was investigated on 9 indexes (hair form, forehead hair-ledge point, eyefold of the upper eyelid, Mongoloid fold, ear lobe type, nasal profile, nostril type, front teeth type, and chin projection) in the Hulunbuir league, Inner Mongolia in September 1997. The results are as follows: 1. Most of the Mongolians in Hulunbuir league are characterised by straight hair, forehead hair-ledge point absence, eyefold eyelid, Mongoloid fold appearance, shovel-shaped front teeth, straight nose, wide nostril, free ear lobe, non-projecting chin. 2. The frequencies of the forehead hair-ledge point appearance, shovel-shaped front teeth appearance and projecting chin showed significant differences between the three groups. 3. The incidence of ear lobe type, nasal profile and front teeth type showed obvious sexual differences. 4. Correlations did not occur between most of the nine traits.

[Gene frequency of 12 characters in 5 nationalities in inner mongolia].

The gene frequency of 12 characters was reported in Ewenki, Oroqen, Daur, Mongol and Han nationalities in Inner Mongolia, and compared among these nationalities. The result indicated that the difference of Mongoloid fold among nationalities was significant, followed by the Folding tongue, while the difference of Handedness and Nasal profile was relatively insignificant.