Seiji Ohsawa

SECULAR CHANGES IN THE STATURE, WEIGHT, AND AGE AT MAXIMUM GROWTH INCREMENTS OF URBAN CHINESE GIRLS FROM THE 1950S TO 1985

This study focuses on changes in the stature, weight, and age at maximum increments in Chinese urban girls 7–17 years of age between the 1950s and 1985. The data come from anthropometric surbeys in the 1950s, 1960s, 1970s, and 1985 in 17 Chinese cities. An overall increasing trend is apparent for stature and weight. The average increments are 1.91 cm and 0.57 kg per decade for 7 year olds, 3.43 cm per decade for 11 year olds, 2.11 kg per decade for 13 year olds, and 1.27 cm and 0.73 kg per decade for 17 year olds. Girls in 1985 attained peak growth earlier, by 1.08 years or 0.04 year/decade, than girls in the generation 30 years earlier. Specific comprisons of changes in body size and age at maximum increments during 1950–1960, 1960–1970, and 1970–1985 are also reported, and the results are compared with those of other countries or groups.

Age at menarche and comparison of the growth and performance of pre- and post-menarcheal girls in China.

The median menarcheal ages (MMAs) of Chinese girls in 1991 were calculated by using the status quo method and probit analysis in 64,322 schoolgirls 8–18 years of age. The sample was randomly selected from 29 provinces of China. The MMAs were 13.01 ± 1.19 and 13.64 ± 1.24 years for urban and rural girls, respectively. These estimates were 0.16 and 0.20 years lower than that of Chinese urban and rural girls in 1985, respectively. The associations between growth status and the timing of menarche were also analyzed by comparing of 10 indicators of somatic growth and motor ability between the pre‐ and post‐menarcheal girls. Early maturers consistently have high means of stature, weight, and vital capacity than late maturers. By contrast, the late maturers tend to have a linear physique and more potential of increasing stature and lower limbs into late adolescence. Late maturers also tend to have more potential in catching up in motor abilities, which were inferior to those of early maturers during early adolescence. Am. J. Hum. Biol. 9:205–212, 1997.

Growth changes of Chinese Mongolian, Uygur, Korean, and Tibetan ethnic groups in the past forty years

Growth changes in stature and weight between 1950–60s and 1991 of four Chinese ethnic groups were surveyed: the Mongolian, Uygur, Korean, and Tibetan minorities. The subjects were school children and youths aged 7 through 17 years who lived in the urban areas of Huhehaote city, Wulumuqi city, and Lasa city, where the corresponding groups lived. An overall increase in body size was found in both boys and girls. Increments of stature and weight for the four groups were as high as 3.22–4.15 cm/decade and 1.72–2.74 kg/decade for boys aged 13, and 2.41–4.01 cm/decade and 1.13–2.41 kg/decade for girls aged 11. Children in 1991 also showed a trend of attaining the adolescent growth spurt earlier than the generation of 30–40 years ago. However, the comparison of the growth status of the four groups with the Chinese Han showed that changes in these ethnic groups over the past 30–40 years were not sufficient to make up for the growth deficits incurred during their long histoies. Factors underlying these growth changes were discussed, and strategies for further improvement of growth were suggested.

Onset of the release of spermatozoa (spermarche) in Chinese male youth

Data on the prevalence of the first ejaculating emission for 83,902 Chinese boys 9 through 18 years were collected using interviews. Median spermarcheal ages (MSAs) were calculated by using the status quo data and probit analysis. Subjects consisted of 61,812 Han boys from urban and rural areas in 29 provinces, and 22,090 minority boys from 17 minority ethnic groups. Median spermarcheal ages were 14.24 years for urban Han boys and 14.85 years for rural Han boys, and ranged from 13.46 to 16.32 years for the 17 minority ethnic groups. The differences in MSAs between urban and rural Han boys in each province were significant and the correlation between MSA of urban and rural boys in each province was high (r = 0.83, P < 0.001). For both urban and rural Han boys, there were significant geographic variations. MSAs of boys living in north China were generally higher than those living in the south, while those living in the west were higher than those living in the east. Variation in MSA may be related to ecological conditions in the Chinese Han populations. The different estimates of spermarcheal ages with two approaches, periodical urine sample analysis vs. interview, and their effect on estimating male puberty are discussed. Am. J. Hum. Biol. 12:577–587, 2000.

Changes in somatotype during growth in Chinese youth 7–18 years of age

Heath‐Carter anthropometric somatotypes were calculated for 7,710 Chinese youths (4,434 boys and 3,276 girls), 7–18 years of age in the context of sex and age differences in distributions during adolescence. Age‐specific trends are characterized by a consistent increase in endomorphy in girls and generally stable mesomorphy in boys. Somatotypes are consistently dominant in mesomorphy in boys and in endomorphy in girls across all ages. Somatotype distributions in the 13 somatotype categories of Heath‐Carter somatochart appear to be broader in girls than in boys, and is more influenced by age in girls than in boys. Comparisons with other Asian samples and with Canadian youth suggest racial/ethnic variation in somatotype.

Effects of habitual physical exercise and aortic distensibility on systolic blood pressure (BP) in males: a study using aortic pulse wave velocity

The authors hypothesized that habitual physical exercise and aortic distensibility would be the major factors which influence systolic blood pressure. This study was designed to analyze the relationships among systolic blood pressure (SBP) and parameters determined at medical checks, including age, diastolic blood pressure (DBP), aortic pulse wave velocity (APWV) index (APWVI : APWV standardized by the diastolic blood pressure), plasma lipid profiles (IC, TG), plasma glucose during an oral glucose tolerance test (2 h-OGTT), percentage body fat (%Fat), cigarette smoking habit (Cigarettes), alcohol consumption (Alcohol), and physical activity index (PAI) using a questionnaire, in 678 males aged 30 to 69 years, who visited a hospital for a thorough medical checkup. For analysis of factorial structure in the subjects, principal factor analysis was applied to the correlation matrix which was calculated with 12 variables. Correlational analysis and path analysis were applied to confirm the hypothetical model. The results demonstrated that DBP and APWVI were the major factors which significantly affected the SBP. The PAI was significantly and inversely correlated not only with the APWVI, but also with %Fat, which was significantly and positively correlated with the DBP. In conclusion, aortic wall stiffness may be an independent factor in the manifestation of systolic hypertension, and habitual physical exercise may decrease the SBP through direct reduction of aortic wall stiffness and indirectly decreasing the DBP. (Jpn. J. Phys. Fitness Sports Med. 1998, 47: 313•`326) key words : habitual physical exercise, aortic pulse wave velocity, aortic distensibility, systolic hypertension