Sex, Sport, IGF-1 and the Community Effect in Height Hypothesis

Association between lifestyle and height growth in high school students

Introduction

An important indicator that plays a pivotal role in examining the health of individuals living in a community is their height. The aim of this study was to examine the relationship between lifestyle and height among female high school students in Dezful, Iran.

Methods

This research was a cross-sectional descriptive-analytical study. Participants included 351 female high school students who were selected from public and private high schools in Dezful using random cluster sampling. Miller-Smith Lifestyle Assessment Inventory was used to collect data about students' lifestyles, and their height was measured based on self-report.

Results

The total lifestyle score of the study participants was 52.23 ± 11.31. Also, 30.2%, 67.2%, and 2.6% of the students had high, moderate, and low lifestyle scores, respectively. A negative and significant relationship was observed between the total score of lifestyle and its components, that is, nutrition, sleep, exercise, and mental stress, and the height growth of female high school students in Dezful (P < 0.05) according to Pearson's correlation. Results of regression analysis showed that the total lifestyle score and its components could significantly predict the height growth of students.

Conclusion

Our results are indicative of the relationship between lifestyle and its components with height growth among female high school students.

Level of oxytocin prior to rugby and handball matches: An exploratory study among groups of Polish players

The aim of the present exploratory study was to assess the changes in urinary oxytocin (OT) concentration during the period between five days before, and on the day of match, among rugby and handball players. Nine male rugby players with a mean age of 27.62 years (SD = 4.21) and 18 male handball players with a mean age of 17.03 years (SD = 0.57) participated. Urinary oxytocin level was measured by ELISA immunoassay as a ratio to the concentration of creatinine [mg/ml] measured through colorimetric detection. The relative level of OT to creatinine (OT/CRE) significantly differed between the type of player (rugby or handball) but not between times of measurements. Significant differences were only between OT/CRE level in a day of match in rugby players and in 5 days before match in handball players (p<0.05). There was no change in oxytocin levels during the time periods between five days before and on the day of a match, in either of the two kinds of players. The change in oxytocin might be traceable during the match but not before a match and this perhaps depends on a more subtle context of competition, but not on the assumption of competition. Further studies are needed based on more homogenous group with higher number of matches.

An increase in the developmental tempo affects the secular trend in height in male Austrian conscripts birth cohorts 1951-2002

OBJECTIVES

Using population-based data on height in Austria from birth cohort 1951 to 2002, we aim to evaluate the secular trends in height and developmental tempo among Austrian young men.

METHODS

Data were obtained from the Austrian conscription medical examination. We included 1 205 112 conscripts (18-<20 years) who were born between 1951 and 2002 and 853 645 conscripts (17-<19 years) who were born between 1961 and 2002. Height was measured during the medical examination and was used to evaluate the secular trends of mean height over time. Furthermore, the mean difference in height between conscripts of 17- and 18 years old were compared across birth cohorts.

RESULTS

The mean height of conscripts aged 17 years increased by 2.2 cm (p < .0001) in between 1961 and 2002. The mean height of conscripts aged 18 years increased by 4.3 cm (p < .0001) between 1951 and 2002. However, the increase in mean height has slowed down since the 1970 s. The difference in mean height between 17 and 18 years old widened from about 0.1 cm in 1961 to 0.3 cm around 1970 and then steadily narrowed again to 0.1 cm at the end of the study period.

CONCLUSIONS

The increasing trend in height slows at the end of the 20th century, the developmental tempo at the population level, however, continued to increase. The difference in mean height between 17 and 18 years old narrowed, which may indicate that young men reached their final height earlier.

Fear, violence, inequality, and stunting in Guatemala

BACKGROUND

Stunting is defined by the public health community as a length- or height-for-age <-2 SD of a growth standard or reference and is claimed to be caused by poor nutrition, repeated infection, and inadequate psychosocial stimulation.

MATERIAL AND METHODS

Stunting is common at all income levels in middle- and low-income countries. At the higher income levels, stunting is unlikely to be caused by nutrient deficiency or infectious disease.

RESULTS

In Guatemala, 17% of <5-year-olds in the highest family income quintile are stunted. Guatemala has a history of violence from armed conflict, current-day social and economic inequalities, government corruption, and threat of kidnapping for the wealthiest families.

DISCUSSION AND CONCLUSION

The high level of persistent violence creates an ecology of fear, an extreme range of inequalities in Social-Economic-Political-Emotional resources, and biosocial stress that inhibits skeletal growth and causes stunting for people of all income levels.

Reducing socioeconomic differences in anthropometric characteristics among young Polish women

The aim of this paper was to evaluate the socioeconomic differences in adult anthropometric parameters of young women in Poland. The study was cross-sectional and conducted in the years 2015 to 2018 among 1257 women aged 19-24 years. The heights, weights, wrist widths and waist, hip and chest circumferences of the subjects were measured. Body mass index (BMI), waist-to-hip ratio (WHR), waist-to-height ratio (WHtR), waist-to-chest ratio (WCR) and chest-to-height ratio (CHtR) were calculated. A survey was conducted to collect data on the women's socioeconomic characteristics. The application of the Generalized Linear Model (GLM) including all socioeconomic indicators (urbanization level of place of residence in childhood, parental education, number of siblings, material conditions) revealed no significant association of these with any of the analysed anthropometric traits. The results of the logistic regression showed no significant differences in the risk of underweight, too low abdominal adiposity or too high abdominal adiposity. However, the risk of overweight and obesity was significantly affected by the degree of urbanization of the women's place of residence in childhood and by their number of siblings. The results show that the socioeconomic factors that once had a significant influence on anthropometric traits currently do not play such an important role. This change can be explained by the equalization of living conditions and lifestyles of individual social groups in Poland.

Adult body height as a mediator between early-life conditions and socio-economic status: the case of the Dutch Potato Famine, 1846-1847

Adult body height appears to be a relatively accurate summary variable of early-life exposures' influence on health, and may be a useful indicator of health in populations where more traditional health-related indicators are lacking. In particular, previous studies have shown a strong, positive relationship between environmental conditions in early life (particularly nutritional availability and the disease environment) and adult height. Research has also demonstrated positive associations between height and socioeconomic status. We therefore hypothesize that height mediates the relationship between early-life conditions and later-life socio-economic outcomes. We also hypothesize that the period of exposure in early life matters, and that conditions during pregnancy or the first years of life and/or the years during puberty have the largest effects on height and socio-economic status. To test these relationships, we use a sample of 1817 Dutch military conscripts who were exposed during early life to the Dutch Potato Famine (1846-1847). We conduct mediation analyses using structural equation modelling, and test seven different time periods in early-life. We use potato prices and real wages to proxy early-life environmental conditions, and occupational status (using the HISCAM scale) to proxy socioeconomic status. We find no evidence of mediation, partial or full, in any models. However, there are significant relationships between potato prices in adolescence, height and socio-economic status. To determine causality in these relationships, further research is needed.

Social mobility of the father influences child growth: A three-generation study

OBJECTIVES

The association between body height and social status is known. We were interested in the effect of intergeneration changes in social status on height.

METHODS

Body height was measured in 2008 paternal grandfather-father-son and 1803 paternal grandfather-father-daughter triplets. The sample consisted of four child cohorts born in 1988, 1985, 1983, and 1980, and was measured annually from 6 to 11, 9 to 14, 11 to 16, and 14 to 18 years of age. Triplets were dichotomized according to grandfathers' occupation, into one "lower" and one "upper" grandparental class; and according to paternal education, into one "lower" and "upper" paternal class, resulting in four "family histories": two nonmobile (grandfathers and fathers stayed in the same social class), and two mobile histories (social class of fathers and grandfathers differed).

RESULTS

"Upper" class fathers are taller than "lower" class fathers. This class effect on height persists into the third generation. Upward social mobility ("lower" class fathers receive secondary or university education) results in taller stature both in the fathers and in the children. The opposite applies for downward social mobility. "Upper" class fathers with only basic or vocational education lose the social advantage and remain shorter. So do their children.

CONCLUSIONS

The class effect on height tends to persist into the next generation, but depends on education. Upward social mobility measured as a "better" education, results in taller stature, up to the third generation. The study highlights the importance of education as a major regulator of body height.

Disparities in Height and Urban Social Stratification in the First Half of the 20th Century in Madrid (Spain)

Adult height is the most commonly used biological indicator to evaluate material and emotional conditions in which people grew up, allowing the analysis of secular trends associated with socio-economic change as well as of social inequalities among human populations. There is a lack of studies on both aspects regarding urban populations. Our study evaluates the secular trends and the disparities in height of conscripts born between 1915 and 1953 and called-up at the age of 21 between 1936 and 1969, living in districts with low versus middle and high socio-economic conditions, in the city of Madrid, Spain. We test the hypothesis that urban spatial segregation and social stratification was associated with significant differences in height. Results show that height increased significantly during the analysed period, both among conscripts living in the middle- and upper-class districts (5.85 cm) and in the lower-class districts (6.75 cm). The positive secular trend in height among conscripts from middle- and upper-class districts was sustained throughout the period, but the trend in height among the lower class fluctuated according to social, political, and economic events. Our findings support previous research that adult height is influenced strongly by the family living conditions during infancy and by community effects acting during childhood and adolescence.

Community-based clustering of height in Ethiopia, India, Peru, and Vietnam

OBJECTIVES

Human growth and final height are influenced by many factors such as genetics, nutrition, living conditions, socioeconomic background and, as recently proposed, by social peer groups and the community. In this paper, we aim to evaluate the extent to which spatial proximity, acting as a proxy for the social community, causes height clustering in low and middle income countries.

MATERIAL AND METHODS

We analyzed data from the study "Young Lives-Measuring Child Poverty and Health", a study performed in four low and middle income countries (Ethiopia, India, Peru and Vietnam) to describe the health situation of children. We used linear mixed effects models with different random effect structures to analyze the influence of the community on clustering of height in boys and girls.

RESULTS

In all analyzed low and middle income countries, linear mixed effects with hierarchical structures with communities nested within regions provide a better fit than the basic models neglecting community-based clustering (p < .001).

DISCUSSION

Although the underlying mechanisms require future research, spatial proximity arising from clustering needs to be integrated into explorative modelling of height variability in humans.

Monte Carlo simulation of body height in a spatial network

BACKGROUND/OBJECTIVES

Recent evidence suggests clustering of human body height. We want to assess the consequences of connectedness in a spatial network on height clustering in an artificial society.

SUBJECTS/METHODS

We used an agent-based computer modelling technique (Monte Carlo simulation) and compared simulated height in a spatial network with characteristics of the observed geographic height distribution of three historic cohorts of Swiss military conscripts (conscripted in 1884-1891; 1908-1910; and 2004-2009).

RESULTS

Conscript height shows several characteristic features: (1) height distributions are overdispersed. (2) Conscripts from districts with direct inter-district road connections tend to be similar in height. (3) Clusters of tall and clusters of short stature districts vary over time. Autocorrelations in height between late 19th and early 21st century districts are low. (4) Mean district height depends on the number of connecting roads and on the number of conscripts per district. Using Monte Carlo simulation, we were able to generate these natural characteristics in an artificial society. Already 5% height information from directly connected districts is sufficient to simulate the characteristics of natural height distribution. Very similar observations in regular rectangular networks indicate that the characteristics of Swiss conscript height distributions do not so much result from the particular Swiss geography but rather appear to be general features of spatial networks.

CONCLUSIONS

Spatial connectedness can affect height clustering in an artificial society, similar to that seen in natural cohorts of military conscripts, and strengthen the concept of connectedness being involved in the regulation of human height.

Different effects of living conditions on the variation in BMI and height in children before the onset of puberty

BACKGROUND/OBJECTIVES

Biological indicators of children's growth, such as the mean values for both height and weight, are often used as markers of change in living conditions. However, little is known about how the quality of life affects the variation in height and weight. Therefore, the aim of this study was to assess the variation in height and body mass index (BMI) in Polish children between 1966 and 2012. During this period, Poland underwent vast political and socioeconomic changes.

SUBJECTS/METHODS

The study included 5597 boys and 5479 girls aged 7-8 years of age. Socioeconomic status (SES) was defined in three categories: high, medium and low.

RESULTS

Between 1966 and 2012, the mean values for height and BMI significantly increased in both sexes (P<0.001). The variation of these two parameters, however, showed a different pattern. Whereas the variation in Z-values for height remained unchanged in both sexes, the variation in BMI increased in boys (P<0.01) but not in girls. SES affected the variation in Z-BMI in 1978 in both sexes (P<0.001), whereas variation in Z-height between SES categories remained unchanged across all years of surveys in boys. Before the political transformation, significant regional differences were observed in the variances of Z-BMI (P<0.05) but not of Z-height. This pattern changed after the political transformation, when regional differences in variances of Z-BMI disappeared.

CONCLUSIONS

It is concluded that the mean values and the variation of BMI are affected by a changing quality of life, whereas the variation in height is usually independent of living conditions.

Height and skeletal morphology in relation to modern life style

Height and skeletal morphology strongly relate to life style. Parallel to the decrease in physical activity and locomotion, modern people are slimmer in skeletal proportions. In German children and adolescents, elbow breadth and particularly relative pelvic breadth (50th centile of bicristal distance divided by body height) have significantly decreased in recent years. Even more evident than the changes in pelvic morphology are the rapid changes in body height in most modern countries since the end-19th and particularly since the mid-20th century. Modern Japanese mature earlier; the age at take-off (ATO, the age at which the adolescent growth spurt starts) decreases, and they are taller at all ages. Preece-Baines modelling of six national samples of Japanese children and adolescents, surveyed between 1955 and 2000, shows that this gain in height is largely an adolescent trend, whereas height at take-off (HTO) increased by less than 3 cm since 1955; adolescent growth (height gain between ATO and adult age) increased by 6 cm. The effect of globalization on the modern post-war Japanese society (“community effect in height”) on adolescent growth is discussed.