Variation In Body Height Research Articles

Sex Differences in Genetic and Environmental Factors Contributing to Body-Height

AbstractSex differences in the heritability of self-reported body-height in two Finnish twin cohorts were studied by using sex-limitation models. The first cohort was born in 1938–1949 (N = 4873 twin pairs) and the second in 1975–1979 (N = 2374 twin pairs). Body-height was greater in the younger cohort (difference of 3.1 cm for men and 2.9 cm for women). The heritability estimates were higher among men (h2 = 0.87 in the older cohort and h2 = 0.82 in the younger cohort) than women (h2 = 0.78 and h2 = 0.67, respectively). Sex-specific genetic factors were not statistically significant in either cohort, suggesting that the same genes contribute to variation in body height for both men and women. The stronger contribution of environmental factors to body-height among women questions the hypothesis that women are better buffered against environmental stress, at least for this phenotype.

Körperhöhenschwankungen im Verlaufe eines Arbeitstages

Variation of body height during the day has been analyzed considering the influence of various occupations (standing, sitting, mixed) on the posture. In addition to this the following variables have been recorded on the 302 individuals under study: Sex, age, working time, time of getting up in the morning, kind of occupation, physique, sporting activities in the leisure-time, presence of defects of the spinal column, possibility of changes of the carriage at the working place and extensibility of the spinal column. The statistical analysis showed that with the exception of pathological alterations of the spinal column all these variables are influencing the variation of body height during the day. It could also be shown that the extensibility of the spinal column does not vary during the day. The author is discussing also ergonomical rules concerning the organization of working places for standing and sitting occupations. Finally some recommendations for the future organization of such places are given.

Height and weight differences among South African Urban schoolchildren born in various months of the year.

Among 1,165 subjects aged 6-18 years who were examined once cross-sectionally, a significant variation in body height and weight according to the month of birth of the subjects was found. All subjects belonged to the so-called Cape Coloured community, were born locally, and their parents belonged to the most affluent sector of the community. Individuals born in February to July were shorter and weighed less (by 13 to 17% of the standard deviation) than those born in August to January. These results are similar to those obtained for Canadian children, who were measured on their birthdays. Since our individuals were measured only once, at the same time of the year, observed differences cannot be ascribed to seasonal fluctuations of growth rates prior to measurement but must constitute a persistent effect of seasonal fluctuation in earlier growth. Immediate environmental conditions (food, temperature, rainfall, and insolation) in the Southern Hemisphere fluctuate seasonally 6 months out of phase from those in the Northern Hemisphere. Thus the similarity of our findings to those from the Northern Hemisphere suggests a factor common for the entire earth, possibly related to the ellipsoid shape of the orbit of the planet.

ANTHROPOMORPHOLOGY AND CORTICOSTEROID EXCRETION IN NORMAL YOUNG ADULT MALES AND FEMALES.

SummaryIn a previous study the between-sex variation in urinary corticosteroid excretion has been investigated in a group of young adult male and female subjects. It was concluded that this variation was due to variation in body height, weight or surface (body size). The present paper deals with the within-sex influence of anthropomorphic variables (body form) on the urinary corticosteroid excretion pattern. It could be demonstrated that a score of the anthropomorphic indices and hormonal variables were mathematically interdependent in the female, but only very few in the male group. Steroid production thus might determine, to a certain extent, the anthropomorphic constitution.