Kaspar Staub

BMI distribution/social stratification in Swiss conscripts from 1875 to present.

Background/Objectives:We aimed to extend the actual overweight discussion with new unbiased Swiss conscript data from 2005 to 2006, and to present for the first time Swiss data on body mass index (BMI) before 1950 and for the late-nineteenth century.Subjects/Methods:For this study, 19-year-old Swiss male conscripts (draft army; Cantons Bern, Zurich, Basel-Stadt and Basel-Land) from the census of 1875–1879, 1933–1939 and 2005–2006 (N=28 033; 2005–2006 census) were included. BMI distribution (World Health Organization (WHO) classification) and social stratification (International Labour Organization classification) were main outcome measures.Results:Mean BMI of 19-year-old men in Switzerland increased in the 50 years between the 1870s and the 1930s by 0.80 kg/m2 and between the 1930s and 2005 by 1.45 kg/m2. The modern BMI sample is much more right skewed and s.d. is higher. Obesity prevalence (according to modern WHO classification) has increased by a factor of 105 from 1870s until present. Over 23% of our representative sample of Swiss men in 2005–2006 had a BMI of over 25 kg/m2. In 2005–2006, contrary to the nineteenth century, unskilled workers had articulately higher BMI values at the 75th, 90th and 95th percentile than students; 12% of unskilled workers were obese against 2% of students.Conclusions:It thus seems that BMI relations between the upper and the lower end of the socio-economic strata changed inversely from the late-nineteenth century to 2005–2006. We further propose that the phenomenon of massive right-skewing BMI distribution between the 1930s and 2005–2006 affected the lower socio-economic strata to a far greater extent than the higher socio-economic group.

Socioeconomic, temporal and regional variation in body mass index among 188,537 Swiss male conscripts born between 1986 and 1992.

Background Rising levels of overweight and obesity are important public-health concerns worldwide. The purpose of this study is to elucidate their prevalence and trends in Switzerland by analyzing variations in Body Mass Index (BMI) of Swiss conscripts. Methods The conscription records were provided by the Swiss Army. This study focussed on conscripts 18.5–20.5 years of age from the seven one-year birth cohorts spanning the period 1986–1992. BMI across professional status, area-based socioeconomic position (abSEP), urbanicity and regions was analyzed. Two piecewise quantile regression models with linear splines for three birth-cohort groups were used to examine the association of median BMI with explanatory variables and to determine the extent to which BMI has varied over time. Results The study population consisted of 188,537 individuals. Median BMI was 22.51 kg/m2 (22.45–22.57 95% confidence interval (CI)). BMI was lower among conscripts of high professional status (−0.46 kg/m2; 95% CI: −0.50, −0.42, compared with low), living in areas of high abSEP (−0.11 kg/m2; 95% CI: −0.16, −0.07 compared to medium) and from urban communities (−0.07 kg/m2; 95% CI: −0.11, −0.03, compared with peri-urban). Comparing with Midland, median BMI was highest in the North-West (0.25 kg/m2; 95% CI: 0.19–0.30) and Central regions (0.11 kg/m2; 95% CI: 0.05–0.16) and lowest in the East (−0.19 kg/m2; 95% CI: −0.24, −0.14) and Lake Geneva regions (−0.15 kg/m2; 95% CI: −0.20, −0.09). Trajectories of regional BMI growth varied across birth cohorts, with median BMI remaining high in the Central and North-West regions, whereas stabilization and in some cases a decline were observed elsewhere. Conclusions BMI of Swiss conscripts is associated with individual and abSEP and urbanicity. Results show regional variation in the levels and temporal trajectories of BMI growth and signal their possible slowdown among recent birth cohorts.

The impact of physical connectedness on body height in Swiss conscripts

BACKGROUND Human populations differ in height. Recent evidence suggests that social networks play an important role in the regulation of adolescent growth and adult height. We further investigated the effect of physical connectedness on height. MATERIAL AND METHODS We considered Switzerland as a geographic network with 169 nodes (district capitals) and 335 edges (connecting roads) and studied effects of connectedness on height in Swiss conscript from 1884 - 1891, 1908 - 1910, and 2004 - 2009. We also created exponential-family random graph models to separate possible unspecific effects of geographic vicinity. RESULTS In 1884 - 1891, in 1908 - 1910, and in 2004 - 2009, 1(st), 2(nd) and 3(rd) order neighboring districts significantly correlate in height (p < 0.01). The correlations depend on the order of connectedness, they decline with increasing distance. Short stature districts tend to have short, tall stature districts tend to have tall neighbors. Random network analyses suggest direct road effects on height. Whereas in 1884 - 1891, direct road effects were only visible between 1(st) order neighbors, direct road effects extended to 2(nd) and 3(rd) in 1908 - 1910, and in 2004 - 2009, also to 4(th) order neighbors, and might reflect historic improvements in transportation. The spatial correlations did not significantly change when height was controlled for goiter (1884 - 1889) and for median per capita income (2006), suggesting direct road effects also in goiter-allowed-for height and income-allowed-for height. CONCLUSION Height in a district depends on height of physically connected neighboring districts. The association decreases with increasing distance in the net. The present data suggest that people can be short because their neighbors are short; or tall because their neighbors are tall (community effect on growth). Psycho-biological effects seem to control growth and development within communities that go far beyond our current understanding of growth regulation.

Skeletal robustness and bone strength as measured by anthropometry and ultrasonography as a function of physical activity in young adults

During the last 10 years, skeletal robustness in children has generally decreased. The reasons for this phenomenon, as well as its outcomes, are undetermined so far.

LESSONS FROM HISTORY OF SOCIOECONOMIC IMPROVEMENTS: A NEW APPROACH TO TREATING MULTI-DRUG-RESISTANT TUBERCULOSIS

This study investigated the trends in tuberculosis mortality through time in Switzerland. Information on the decline in mortality before chemotherapies were introduced may be useful in developing countries where drug-resistant tuberculosis is now becoming a major problem. Swiss data were collected from historical records and comparative data were obtained from the literature for England and Wales, New York, Japan, Brazil and Sierra Leone. Logistic curves were fitted to examine the rate of decline before introduction of pharmacotherapies and these show that the decline would have continued without the introduction of chemical therapies, including antibiotics. In Switzerland, England and Wales and New York, the decline had occurred long before the introduction of specific anti-tuberculosis agents. In Brazil and Japan, chemical therapy was co-incident with the decline in tuberculosis mortality rates. Overall, it is suggested that the effective control of tuberculosis can be achieved through a combination of chemical interventions, conservative therapy (rest, good nutrition, ventilation, etc.) as well as public health interventions addressing hygiene, nutrition, reducing exposure to infections and educating the population about tuberculosis.

From left-skewness to symmetry: how body-height distribution among Swiss conscripts has changed shape since the late 19th century.

Abstract Background: It is generally accepted that height distribution in modern populations is nearly symmetrical. However, it may deviate from symmetry when nutritional status is inadequate. Aim and subjects: This study provides an analysis of changes in the shape of the height distributions among Swiss conscripts (n = 267 829) over the past 130 years based on a highly representative, standardized and unchanged data source. Results: The analysed distributions from the 1870s–1890s conscription years are markedly left-skewed (−0.76 to −0.82), with short and very short men significantly over-represented. Standard deviation is 7.7 cm. In particular, the left tails of the late-19th- and early-20th-century distributions are very heavy. In the first half of the 20th century the first signs of a diminution of the heavy left tail are observable, by the 1970s the phenomenon disappears and height distribution becomes symmetrical; standard deviation is now 6.5 cm. Conclusion: The relatively strong left-skewness during the late 19th and early 20th centuries may have been due to the interaction of a number of causes, chiefly malnutrition, a wider range in physical development at age 19 and widespread iodine deficiency.

From Undernutrition to Overnutrition: The Evolution of Overweight and Obesity among Young Men in Switzerland since the 19th Century

Objective: The global obesity epidemic continues, new approaches are needed to understand the causes. We analyzed data from an evolutionary perspective, stressing developmental plasticity. Methods: We present diachronical height, weight, and BMI data for 702,902 Swiss male conscripts aged 18-20 years, a representative, standardized and unchanged data source. Results: From 1875 to 1879, the height distribution was slightly left-skewed; 12.1% of the conscripts were underweight, overweight and obesity were rare. The BMI-to-height relationship was positive but not linear, and very short conscripts were particularly slim. Since the 1870s, Swiss conscripts became taller, a trend that markedly slowed in the 1990s. In contrast, weight increased in two distinct steps at the end of the 1980s and again after 2002. Since 2010, BMI did not increase but stabilized at a high level. Conclusions: The body of young men adapted differently to varying living conditions over time: First, less investment in height and weight under conditions of undernutrition and food uncertainty; second, more investment in height under more stable nutritional conditions; third, development of obesity during conditions of plateaued height growth, overnutrition, and decreasing physical activity. This example contributes to the evaluation of hypotheses on human developmental plasticity.

Body Height of Mummified Pharaohs Supports Historical Suggestions of Sibling Marriages

Body height is an important factor in reconstructing health conditions and it serves as an indicator of socio-economic status. Researchers rely on ancient data to analyze evolutionary aspects of human health and its interrelation with environmental influences. This study presents body height estimates from all periods of ancient Egyptian history and compares the general population with the existing mummies of the members of royal families. A sample of 259 adult Egyptian mummies originating from various collections and published sources with body lengths (long bone measures or/and overall measurements, CT data) were analyzed, and royal mummies were scored with respect to the level of consanguinity. Male royals were taller than males in the general ancient Egyptian population, while female royals were shorter than females in the general population. The body height variation of the royals is significantly reduced when compared with a pool of non-royal mummies. This provides evidence for inbreeding resulting from consanguineous marriages. However, there appears to be no correlation between the level of inbreeding and individual body height. The random sample of general population does not show signs of inbreeding. Due to the present lack of larger, technically and ethically challenging genetic studies, the selected non-invasive approach of body height is the most reliable indicator of sibling marriages of pharaohs based on direct physical evidence.

From growth in height to growth in breadth: the changing body shape of Swiss conscripts since the late 19th century and possible endocrine explanations.

Because Swiss conscription has been mandatory and standardized since 1875 and measurement procedures for height and weight have not changed, recruitment data (representative for 80-100% of the living young men) provide a solid foundation for a detailed study of changes of young men in Switzerland over the past 140 years. The average Swiss body height increased markedly by 15 cm between the 1870s and the 1970s (birth years). Improvements in living conditions are likely to have been among the main environmental determinants of this increase, but there are other likely candidates, all of which worked via the endocrine system. First, widespread iodine deficiency at the end of the 19th century helps to account for an overrepresentation of very short conscripts, for the low level of average height in Switzerland in general as well as for the tremendous regional variation in average height. Second, the doubling of annual per capita milk consumption between 1875 and 1900 was probably a key factor in the height increase, operating directly on IGF-1 concentration. Third, public-health measures, such as the iodine-deficiency prophylaxis via weekly iodine tablets for schoolchildren and via iodized table salt, introduced in the 1920s, may have been largely responsible for the dramatic increase in height during the interwar period. Since the 1970s (birth years), the positive height trend slowed down, body shape in Switzerland has evolved from growth in height to growth in breadth. Precisely how todays complex of genetic, epigenetic, environmental, and endocrine factors limiting height growth and promoting body breadth and excess weight operates has yet to be completely understood.

Edouard Mallet's early and almost forgotten study of the average height of Genevan conscripts in 1835

In 1835, Edouard Mallet published a notable but today nearly forgotten study of the average height of Genevan conscripts. His individual data included 3029 conscripts born between 1805 and 1814, examined and measured between 1826 and 1835. Mallets work was only the third auxological study to be based on a large sample of individual conscript data, the other two being those of Louis-René Villermé and Adolphe Quetelet, but as far as we know Mallets was the first to note the law of normal distribution. Like Villermé and Quetelet, Mallet explained urban/rural and international differences in average height strictly in terms of environmental and economic determinants. In the recent past, references to Mallets work have been rare, and limited to citations of his computed averages. We postulate that Mallet and his study deserve greater consideration for their contribution to the field of anthropometric history than they have yet received.