An Unwanted but Long-Known Company: Post-Viral Symptoms in the Context of Past Pandemics in Switzerland (and Beyond)

Objectives: Some people do not fully recover from an acute viral infection and experience persistent symptoms or incomplete recovery for months or even years. This is not unique to the SARS-CoV-2 virus and history shows that post-viral conditions like post COVID-19 condition, also referred to as Long Covid, are not new. In particular, during and after pandemics caused by respiratory viruses in which large parts of the population were infected or exposed, professional and public attention was increased, not least because of the large number of people affected. Methods: Given the current relevance of the topic, this article aims to narratively review and summarize the literature on post-viral symptoms during past pandemics and to supplement and illustrate it with Swiss examples from the pandemics of 1890, 1918-1920 and later. Results: Post-viral diseases were an increasingly emphasised health topic during and after past pandemics triggered by respiratory infections over the last 150 years. Conclusion: In the next pandemic, it should not be surprising that post-viral conditions will again play a role, and pandemic plans should reflect this.

Health of singleton neonates in Switzerland through time and crises: a cross-sectional study at the population level, 2007-2022

BACKGROUND

Being exposed to crises during pregnancy can affect maternal health through stress exposure, which can in return impact neonatal health. We investigated temporal trends in neonatal outcomes in Switzerland between 2007 and 2022 and their variations depending on exposure to the economic crisis of 2008, the flu pandemic of 2009, heatwaves (2015 and 2018) and the COVID-19 pandemic.

METHODS

Using individual cross-sectional data encompassing all births occurring in Switzerland at the monthly level (2007-2022), we analysed changes in birth weight and in the rates of preterm birth (PTB) and stillbirth through time with generalized additive models. We assessed whether the intensity or length of crisis exposure was associated with variations in these outcomes. Furthermore, we explored effects of exposure depending on trimesters of pregnancy.

RESULTS

Over 1.2 million singleton births were included in our analyses. While birth weight and the rate of stillbirth have remained stable since 2007, the rate of PTB has declined by one percentage point. Exposure to the crises led to different results, but effect sizes were overall small. Exposure to COVID-19, irrespective of the pregnancy trimester, was associated with a higher birth weight (+12 grams [95% confidence interval (CI) 5.5 to 17.9 grams]). Being exposed to COVID-19 during the last trimester was associated with an increased risk of stillbirth (odds ratio 1.24 [95%CI 1.02 to 1.50]). Exposure to the 2008 economic crisis during pregnancy was not associated with any changes in neonatal health outcomes, while heatwave effect was difficult to interpret.

CONCLUSION

Overall, maternal and neonatal health demonstrated resilience to the economic crisis and to the COVID-19 pandemic in a high-income country like Switzerland. However, the effect of exposure to the COVID-19 pandemic is dual, and the negative impact of maternal infection on pregnancy is well-documented. Stress exposure and economic constraint may also have had adverse effects among the most vulnerable subgroups of Switzerland. To investigate better the impact of heatwave exposure on neonatal health, weekly or daily-level data is needed, instead of monthly-level data.

Worldwide trends in underweight and obesity from 1990 to 2022: a pooled analysis of 3663 population-representative studies with 222 million children, adolescents, and adults

BACKGROUND

Underweight and obesity are associated with adverse health outcomes throughout the life course. We estimated the individual and combined prevalence of underweight or thinness and obesity, and their changes, from 1990 to 2022 for adults and school-aged children and adolescents in 200 countries and territories.

METHODS

We used data from 3663 population-based studies with 222 million participants that measured height and weight in representative samples of the general population. We used a Bayesian hierarchical model to estimate trends in the prevalence of different BMI categories, separately for adults (age ≥20 years) and school-aged children and adolescents (age 5-19 years), from 1990 to 2022 for 200 countries and territories. For adults, we report the individual and combined prevalence of underweight (BMI <18·5 kg/m2) and obesity (BMI ≥30 kg/m2). For school-aged children and adolescents, we report thinness (BMI <2 SD below the median of the WHO growth reference) and obesity (BMI >2 SD above the median).

FINDINGS

From 1990 to 2022, the combined prevalence of underweight and obesity in adults decreased in 11 countries (6%) for women and 17 (9%) for men with a posterior probability of at least 0·80 that the observed changes were true decreases. The combined prevalence increased in 162 countries (81%) for women and 140 countries (70%) for men with a posterior probability of at least 0·80. In 2022, the combined prevalence of underweight and obesity was highest in island nations in the Caribbean and Polynesia and Micronesia, and countries in the Middle East and north Africa. Obesity prevalence was higher than underweight with posterior probability of at least 0·80 in 177 countries (89%) for women and 145 (73%) for men in 2022, whereas the converse was true in 16 countries (8%) for women, and 39 (20%) for men. From 1990 to 2022, the combined prevalence of thinness and obesity decreased among girls in five countries (3%) and among boys in 15 countries (8%) with a posterior probability of at least 0·80, and increased among girls in 140 countries (70%) and boys in 137 countries (69%) with a posterior probability of at least 0·80. The countries with highest combined prevalence of thinness and obesity in school-aged children and adolescents in 2022 were in Polynesia and Micronesia and the Caribbean for both sexes, and Chile and Qatar for boys. Combined prevalence was also high in some countries in south Asia, such as India and Pakistan, where thinness remained prevalent despite having declined. In 2022, obesity in school-aged children and adolescents was more prevalent than thinness with a posterior probability of at least 0·80 among girls in 133 countries (67%) and boys in 125 countries (63%), whereas the converse was true in 35 countries (18%) and 42 countries (21%), respectively. In almost all countries for both adults and school-aged children and adolescents, the increases in double burden were driven by increases in obesity, and decreases in double burden by declining underweight or thinness.

INTERPRETATION

The combined burden of underweight and obesity has increased in most countries, driven by an increase in obesity, while underweight and thinness remain prevalent in south Asia and parts of Africa. A healthy nutrition transition that enhances access to nutritious foods is needed to address the remaining burden of underweight while curbing and reversing the increase in obesity.

FUNDING

UK Medical Research Council, UK Research and Innovation (Research England), UK Research and Innovation (Innovate UK), and European Union.

Trends of physical fitness related to weight status: An analysis including over 412,000 Swiss young male conscripts from 2007 to 2022

Objective

The high prevalence of obesity among young adults in the civilian population pose challenges in recruiting physically fit soldiers. We assessed the trend of physical fitness related to weight status among Swiss male conscripts.

Methods

Cross-sectional data of medical examination data during mandatory conscription for the Swiss Armed Forces, 2007-2022 (N = 412,186). The conscription physical test (CPT) assessed five aspects of physical fitness, each aspect scoring 0-25, one component being an endurance test (ET). CPT and ET categories were defined as per military guidelines: "Insufficient", "Sufficient", "Good", "Very Good" and "Excellent". Weight status was based on body mass index (BMI).

Results

Conscripts with obesity (BMI ≥ 30 kg/m2) and overweight (BMI 25-29.99) had significantly (p < 0.001) lower CPT and ET scores compared to normal weight [multivariable-adjusted mean: 54.7 ± 0.1 and 66.5 ± 0.1, vs. 73.6 ± 0.1 for CPT; 8.8 ± 0.1 and 12.5 ± 0.1, vs. 15.3 ± 0.1 for ET] and a higher likelihood to be categorized as "Insufficient" [weighted relative-risk ratio and (95 %CI): 70.4 (63.7-77.7) and 2.35 (2.16-2.55) for CPT; 77.1 (71.0-83.7) and 3.05 (2.91-3.20) for ET] or "Sufficient" [7.67 (7.38-7.97) and 2.02 (1.99-2.06) for CPT; 8.93 (8.37-9.52) and 2.02 (1.98-2.06) for ET]. Compared to normal weight conscripts, the CPT and ET scores decreased over the conscription years for conscripts with obesity (multivariable-adjusted mean yearly change: -0.11 ± 0.02 for CPT; -0.032 ± 0.007 for ET) and overweight (-0.16 ± 0.01 for CPT and -0.044 ± 0.004 for ET).

Conclusion

Male Swiss conscripts with overweight and obesity have lower physical fitness than normal weight conscripts, and this condition tends to worsen over the conscription years.

Associations between 3D surface scanner derived anthropometric measurements and body composition in a cross-sectional study

BACKGROUND

3D laser-based photonic scanners are increasingly used in health studies to estimate body composition. However, too little is known about whether various 3D body scan measures estimate body composition better than single standard anthropometric measures, and which body scans best estimate it. Furthermore, little is known about differences by sex and age.

METHODS

105 men and 96 women aged between 18 and 90 years were analysed. Bioelectrical Impedance Analysis was used to estimate whole relative fat mass (RFM), visceral adipose tissue (VAT) and skeletal muscle mass index (SMI). An Anthroscan VITUSbodyscan was used to obtain 3D body scans (e.g. volumes, circumferences, lengths). To reduce the number of possible predictors that could predict RFM, VAT and SMI backward elimination was performed. With these selected predictors linear regression on the respective body compositions was performed and the explained variations were compared with models using standard anthropometric measurements (Body Mass Index (BMI), waist circumference (WC) and waist-to-height-ratio (WHtR)).

RESULTS

Among the models based on standard anthropometric measures, WC performed better than BMI and WHtR in estimating body composition in men and women. The explained variations in models including body scan variables are consistently higher than those from standard anthropometrics models, with an increase in explained variations between 5% (RFM for men) and 10% (SMI for men). Furthermore, the explained variation of body composition was additionally increased when age and lifestyle variables were added. For each of the body composition variables, the number of predictors differed between men and women, but included mostly volumes and circumferences in the central waist/chest/hip area and the thighs.

CONCLUSIONS

3D scan models performed better than standard anthropometric measures models to predict body composition. Therefore, it is an advantage for larger health studies to look at body composition more holistically using 3D full body surface scans.

Challenges and best practices for digital unstructured data enrichment in health research: A systematic narrative review

Digital data play an increasingly important role in advancing health research and care. However, most digital data in healthcare are in an unstructured and often not readily accessible format for research. Unstructured data are often found in a format that lacks standardization and needs significant preprocessing and feature extraction efforts. This poses challenges when combining such data with other data sources to enhance the existing knowledge base, which we refer to as digital unstructured data enrichment. Overcoming these methodological challenges requires significant resources and may limit the ability to fully leverage their potential for advancing health research and, ultimately, prevention, and patient care delivery. While prevalent challenges associated with unstructured data use in health research are widely reported across literature, a comprehensive interdisciplinary summary of such challenges and possible solutions to facilitate their use in combination with structured data sources is missing. In this study, we report findings from a systematic narrative review on the seven most prevalent challenge areas connected with the digital unstructured data enrichment in the fields of cardiology, neurology and mental health, along with possible solutions to address these challenges. Based on these findings, we developed a checklist that follows the standard data flow in health research studies. This checklist aims to provide initial systematic guidance to inform early planning and feasibility assessments for health research studies aiming combining unstructured data with existing data sources. Overall, the generality of reported unstructured data enrichment methods in the studies included in this review call for more systematic reporting of such methods to achieve greater reproducibility in future studies.

Health of neonates born in the maternity hospital in Bern, Switzerland, 1880-1900 and 1914-1922

The identification of factors impeding normal fetal development and growth is crucial for improving neonatal health. Historical studies are relevant because they show which parameters have influenced neonatal health in the past in order to better understand the present. We studied temporal changes of neonatal health outcomes (birth weight, gestational age, stillbirth rate) and the influence of different cofactors in two time periods. Moreover, we investigated particularly neonatal health in the wake of the 1918/19 influenza pandemic. Data were transcribed from the Bern Maternity Hospital and consists of two time periods: A) The years 1880, 1885, 1890, 1895 and 1900 (N = 1530, births' coverage 20%); B) The years 1914-1922 (N = 6924, births' coverage 40-50%). Linear regression models were used to estimate the effect of birth year on birth weight, and logistic regression models to estimate the effect of birth year and of the exposure to the pandemic on premature birth, stillborn and low birth weight (LBW). Mean birth weight increased only minimally between the two datasets; whereas, in the years 1914-1922, the preterm birth and stillbirth rates were markedly reduced compared with the years 1880-1900. Sex, parity, gestational age and maternal age were significantly associated with birth weight in both time periods. The probability of LBW was significantly increased in 1918 (OR 1.49 (95% CI 1.00-2.23)) and in 1919 (OR 1.55 (95% CI 1.02-2.36)) compared to 1914. Mothers who were heavily exposed to the influenza pandemic during pregnancy had a higher risk of stillbirth (OR 2.27 (95% CI 1.32-3.9)). This study demonstrated that factors influencing neonatal health are multifactorial but similar in both time periods. Moreover, the exposure to the 1918/19 pandemic was less associated with LBW and more associated with an increased risk of stillbirth. If this trend is confirmed by further studies, it could indicate some consistency across pandemics, as similar patterns have recently been shown for COVID-19.

From pandemic to endemic: Spatial-temporal patterns of influenza-like illness incidence in a Swiss canton, 1918-1924

In pandemics, past and present, there is no textbook definition of when a pandemic is over, and how and when exactly a respiratory virus transitions from pandemic to endemic spread. In this paper we have compared the 1918/19 influenza pandemic and the subsequent spread of seasonal flu until 1924. We analysed 14,125 reports of newly stated 32,198 influenza-like illnesses from the Swiss canton of Bern. We analysed the temporal and spatial spread at the level of 497 municipalities, 9 regions, and the entire canton. We calculated incidence rates per 1000 inhabitants of newly registered cases per calendar week. Further, we illustrated the incidences of each municipality for each wave (first wave in summer 1918, second wave in fall/winter 1918/19, the strong later wave in early 1920, as well as the two seasonal waves in 1922 and 1924) on a choropleth map. We performed a spatial hotspot analysis to identify spatial clusters in each wave, using the Gi* statistic. Furthermore, we applied a robust negative binomial regression to estimate the association between selected explanatory variables and incidence on the ecological level. We show that the pandemic transitioned to endemic spread in several waves (including another strong wave in February 1920) with lower incidence and rather local spread until 1924 at least. At the municipality and regional levels, there were different patterns of spread both between pandemic and seasonal waves. In the first pandemic wave in summer 1918 the probability of higher incidence was increased in municipalities with a higher proportion of factories (OR 2.60, 95%CI 1.42-4.96), as well as in municipalities that had access to a railway station (OR 1.50, 95%CI 1.16-1.96). In contrast, the strong fall/winter wave 1918 was very widespread throughout the canton. In general, municipalities at higher altitude showed lower incidence. Our study adds to the sparse literature on incidence in the 1918/19 pandemic and subsequent years. Before Covid-19, the last pandemic that occurred in several waves and then became endemic was the 1918-19 pandemic. Such scenarios from the past can inform pandemic planning and preparedness in future outbreaks.

Intergenerational transmission of height in a historical population: From taller mothers to larger offspring at birth (and as adults)

Changes in growth and height reflect changes in nutritional status and health. The systematic surveillance of growth can suggest areas for interventions. Moreover, phenotypic variation has a strong intergenerational component. There is a lack of historical family data that can be used to track the transmission of height over subsequent generations. Maternal height is a proxy for conditions experienced by one generation that relates to the health/growth of future generations. Cross-sectional/cohort studies have shown that shorter maternal height is closely associated with lower birth weight of offspring. We analyzed the maternal height and offspring weight at birth in the maternity hospital in Basel, Switzerland, from 1896 to 1939 (N = ∼12,000) using generalized additive models (GAMs). We observed that average height of the mothers increased by ∼4 cm across 60 birth years and that average birth weight of their children shows a similarly shaped and upward trend 28 years later. Our final model (adjusted for year, parity, sex of the child, gestational age, and maternal birth year) revealed a significant and almost linear association between maternal height and birth weight. Maternal height was the second most important variable modeling birth weight, after gestational age. In addition, we found a significant association between maternal height and aggregated average height of males from the same birth years at time of conscription, 19 years later. Our results have implications for public health: When (female/maternal) height increases due to improved nutritional status, size at birth-and subsequently also the height in adulthood of the next generation-increases as well. However, the directions of development in this regard may currently differ depending on the world region.

Reinfections and Cross-Protection in the 1918/19 Influenza Pandemic: Revisiting a Survey Among Male and Female Factory Workers

Objectives: The COVID-19 pandemic highlights questions regarding reinfections and immunity resulting from vaccination and/or previous illness. Studies addressing related questions for historical pandemics are limited. Methods: We revisit an unnoticed archival source on the 1918/19 influenza pandemic. We analysed individual responses to a medical survey completed by an entire factory workforce in Western Switzerland in 1919. Results: Among the total of n = 820 factory workers, 50.2% reported influenza-related illness during the pandemic, the majority of whom reported severe illness. Among male workers 47.4% reported an illness vs. 58.5% of female workers, although this might be explained by varied age distribution for each sex (median age was 31 years old for men, vs. 22 years old for females). Among those who reported illness, 15.3% reported reinfections. Reinfection rates increased across the three pandemic waves. The majority of subsequent infections were reported to be as severe as the first infection, if not more. Illness during the first wave, in the summer of 1918, was associated with a 35.9% (95%CI, 15.7-51.1) protective effect against reinfections during later waves. Conclusion: Our study draws attention to a forgotten constant between multi-wave pandemics triggered by respiratory viruses: Reinfection and cross-protection have been and continue to be a key topic for health authorities and physicians in pandemics, becoming increasingly important as the number of waves increases.

Diminishing benefits of urban living for children and adolescents' growth and development

Optimal growth and development in childhood and adolescence is crucial for lifelong health and well-being1-6. Here we used data from 2,325 population-based studies, with measurements of height and weight from 71 million participants, to report the height and body-mass index (BMI) of children and adolescents aged 5-19 years on the basis of rural and urban place of residence in 200 countries and territories from 1990 to 2020. In 1990, children and adolescents residing in cities were taller than their rural counterparts in all but a few high-income countries. By 2020, the urban height advantage became smaller in most countries, and in many high-income western countries it reversed into a small urban-based disadvantage. The exception was for boys in most countries in sub-Saharan Africa and in some countries in Oceania, south Asia and the region of central Asia, Middle East and north Africa. In these countries, successive cohorts of boys from rural places either did not gain height or possibly became shorter, and hence fell further behind their urban peers. The difference between the age-standardized mean BMI of children in urban and rural areas was <1.1 kg m-2 in the vast majority of countries. Within this small range, BMI increased slightly more in cities than in rural areas, except in south Asia, sub-Saharan Africa and some countries in central and eastern Europe. Our results show that in much of the world, the growth and developmental advantages of living in cities have diminished in the twenty-first century, whereas in much of sub-Saharan Africa they have amplified.

Short-termed changes in quantitative ultrasound estimated bone density among young men in an 18-weeks follow-up during their basic training for the Swiss Armed Forces

Background

Quantitative Ultrasound (QUS) methods have been widely used to assess estimated bone density. This study aimed to assess changes in estimated bone density in association with changes in body composition, physical activity, and anthropometry.

Methods

We examined changes in anthropometry, body composition, and physical activity associated with changes in estimated bone mineral density (measured using quantitative ultrasound with a heel ultrasound device indicating broadband ultrasound attenuation BUA and speed of sound SOS) in a follow-up sample of n = 73 young men at the beginning and again 18 weeks later at the end of basic military training.

Results

At the end of the basic training, the subjects were on average significantly heavier (+1.0%), slightly taller (+0.5%) and had a higher fat mass (+6.6%) and grip strength (+8.6%). A significant decrease in mean physical activity (-49.5%) and mean estimated bone density calculated with BUA (-7.5%) was observed in the paired t-test. The results of the multivariable linear regressions (backward selection) show that changes in skeletal muscle mass (delta = 2nd measurement minus 1st measurement) have negative and body weight (delta) have positive association with the speed of sound SOS (delta), while fat mass (delta) and physical activity (delta) had the strongest negative associations with estimated bone mineral density (delta). In particular, we found a negative association between fat mass (delta) and estimated bone mineral density (delta, estimated with BUA).

Conclusion

Our study suggests that estimated bone density from the calcaneus can change within a few months even in young and mostly healthy individuals, depending upon physical activity levels and other co-factors. Further studies including other troop types as control groups as well as on women should follow in order to investigate this public health relevant topic in more depth. To what extent the estimated bone density measurement with quantitative ultrasound is clinically relevant needs to be investigated in further studies.

Body height among adult male and female Swiss Health Survey participants in 2017: Trends by birth years and associations with self-reported health status and life satisfaction

•

Increase in average body height had slowed down from around the 1970s birth cohorts.

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Women and men with tertiary education levels were taller than participants holding other education levels.

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Taller participants were less overweighted and were more satisfied with their lives than shorter participants.

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Taller participants had better overall health than shorter participants.

•

Taller men were more likely to have lower back pain than shorter men.

The increase in adult height for 150 years is linked to overall improvements in nutrition, hygiene, and living standards. Height is positively associated with general health and success on various levels (e.g. quality of life, earnings or happiness). The aim of this study was to investigate whether different subgroups show different trends across birth cohorts. We wanted to know whether taller individuals considered themselves as healthier and their quality of life as better than shorter individuals.

We included 19,435 participants from the Swiss population-based Health Survey 2017. GAM were used to assess nonlinear associations between height and birth year. Multinomial logistic regression was used to predict probabilities of self-rated health in relation to height.

The increase in average height slows down from the 1970s birth cohorts. Participants with parents from Central/Northern/Western Europe (men 177.9 cm, women: 165.1 cm) or Eastern Europe (men 178.7 cm, women: 165.7 cm) were taller than participants with parents from South America (men 174.3 cm, women: 161. cm) and Asia (men 173.2 cm, women: 160.1 cm). Participants with tertiary education were taller than participants from education levels (mean difference men: 4.5 cm, women: 5.0 cm). Height was positively associated with self-declared aspects of health and life satisfaction.

These results support the conclusion that body height as a co-factor of health aspects should be considered in public health research. Although adult body height can no longer be influenced, nutritional status and thus also healthy growth can be influenced in childhood by public health programs, by eliminating social inequalities, and by strengthen healthy living conditions.

Body mass index in young men in Switzerland after the national shutdowns during the COVID-19 pandemic: Results from a cross-sectional monitoring study at the population level since 2010

BACKGROUND

Owing to the COVID-19 pandemic, the Swiss goverment imposed a shutdown twice, which may have changed diet and physical activity. Regarding the question of weight change during the pandemic, little information based on measured weight data is available. We aimed to investigate whether the body mass indices (BMIs) of young Swiss men after the two shutdowns in spring and fall 2020 differed from those of young men examined before the shutdowns.

METHODS

We analysed young Swiss men's BMIs taken during mandatory recruitment for the Swiss Armed Forces at the cross-sectional (not individual longitudinal) monitoring level and across weeks of conscription between January 2010 and July 2021 (n = 373,016). These data allow for continuous health monitoring of young men at almost the population level (coverage, >90%). For statistical modelling, we used the generalised additive model (GAM) framework.

RESULTS

We showed that the BMIs of the conscripts examined in the 15 weeks after the two shutdowns in spring and autumn 2020 were not or only slightly different from their baseline values. Sensitivity analyses revealed that this conclusion also holds if the BMI distribution or prevalence of excess weight is assessed. The GAM further showed the significant effects of individual and area-based measures of socioeconomic position and age on BMI.

CONCLUSION

Our results suggest that lifestyle changes during the pandemic in young men might have been too modest to be reflected in body weight. However, longitudinal data and/or data on women, children, or the elderly may lead to different conclusions.

Body height in adult women and men in a cross-sectional population-based survey in Geneva: temporal trends, association with general health status and height loss after age 50

OBJECTIVE

On the one hand, trends in average height in adulthood mirror changes in living standard and health status of a population and its subgroups; on the other hand, height in general, as well as the loss of height in older age in particular, are associated in different ways with outcomes for health. For these aspects, there is hardly any information for Switzerland based on representative and measured body height data.

DESIGN

Repeated cross-sectional survey study.

SETTING

Fully anonymised data from the representative population-based Geneva Bus Santé Study between 2005 and 2017 were analysed.

METHODS

Data from N=8686 study participants were used in the trend analysis. Height was measured and sociodemographic information and self-rated health was collected via questionnaires. Follow-up (mean: 7.1 years) measurements from N=2112 participants were available to assess height loss after age 50.

RESULTS

Women were, on average, 166.2 cm (SD 6.5) tall and men 179.2 cm (SD 6.5). Among men and women, higher socioeconomic status was associated with taller average height. The flattening of the increase in height from the 1970s birth years appears to begin earlier in the subgroup with the highest education level. The tallest average height was measured for men and women from Central and Northern Europe, the shortest for South America and Asia. The likelihood that participants rated their health as 'very good' increased with greater body height. The follow-up data show that men lost -0.11 cm per follow-up year (95% CI -0.12 to -0.10), women -0.17 cm (95% CI -0.18 to 0.15).

CONCLUSIONS

The association of height and health status is currently understudied. Monitoring changes in average body height may indicate disparities in different subgroups of populations. Based on our study and a growing literature, we think that the multifaceted role of body height should be better considered in clinical practice.

Associations between hydration status, body composition, sociodemographic and lifestyle factors in the general population: a cross-sectional study

Background

Whole-body hydration status is associated with several health outcomes, such as dehydration, edema and hypertension, but little is known about the nonclinical determinants. Therefore, we studied the associations of sex, age, body composition, nutrition, and physical activity on several body hydration measures.

Methods

We assessed sociodemographic variables, dietary habits, and physical activity by questionnaire and body composition by bioelectric impedance analysis (BIA). We compared determinants between the sexes and calculated associations between determinants and BIVA hydration measures by multivariable linear regressions.

Results

A total of 242 adults from the general population (age 18–94, 47% women) were included. Women were younger, smaller, lighter, and had a smaller BMI (kg/m²) than men (p < 0.05). Women had less muscle mass, less visceral fat mass and less extracellular and intracellular water than men (p < 0.001). Women showed less intracellular water per extracellular water than men, while men showed higher phase angle values than women (both p < 0.001). Men had a stronger association of hydration measures with physical activity than women. Both sexes showed a decrease in hydration measures with age.

Conclusions

Sex, age, body composition, and physical activity influence body hydration. There seem to be differences in body water regulation between the sexes. Especially interesting are factors susceptible to preventive measures such as physical activity.

The role of body height as a co-factor of excess weight in Switzerland

Object

Excess weight (Body Mass Index [BMI] ≥25.0 kg/m²) is a major health issue worldwide, including in Switzerland. For high‐income countries, little attention has been paid to body height in context of excess weight. The aim of this study is to assess the importance of body height as a co‐factor for excess weight in multiple large nationwide data sets.

Data and methods

In this comparative study, we included the largest nationwide and population‐based studies in the fields of public health, nutrition and economics for Switzerland, as well as data of the medical examination during conscription for the Swiss Armed Forces, which contained information on BMI and, if possible, waist‐to‐height‐ratio (WHtR) and waist‐to‐hip‐ratio (WHR).

Results

The multinomial logistic regressions show that the probability of belonging to the excess weight category (BMI ≥25.0 kg/m²) decreased with increasing height in both sexes inall contemporary data sets. This negative association was shown to be constant, only among conscripts measured in the 1870s the association was positive, when increasing height was associated with a higher BMI. The negative association not only emerge in BMI, but also in WHtR and WHR.

Conclusion

Our results emphasize the importance of body height as a co‐factor of excess weight, suggesting a clear negative association between height and BMI, WHtR and WHR. Evidence indicates that both early‐life environmental exposures and alleles associated with height may contribute to these associations. This knowledge could serve as further starting points for prevention programs in the field of public health.

Historically High Excess Mortality During the COVID-19 Pandemic in Switzerland, Sweden, and Spain

BACKGROUND

Excess mortality quantifies the overall mortality impact of a pandemic. Mortality data have been accessible for many countries in recent decades, but few continuous data have been available for longer periods.

OBJECTIVE

To assess the historical dimension of the COVID-19 pandemic in 2020 for 3 countries with reliable death count data over an uninterrupted span of more than 100 years.

DESIGN

Observational study.

SETTING

Switzerland, Sweden, and Spain, which were militarily neutral and not involved in combat during either world war and have not been affected by significant changes in their territory since the end of the 19th century.

PARTICIPANTS

Complete populations of these 3 countries.

MEASUREMENTS

Continuous series of recorded deaths (from all causes) by month from the earliest available year (1877 for Switzerland, 1851 for Sweden, and 1908 for Spain) were jointly modeled with annual age group-specific death and total population counts using negative binomial and multinomial models, which accounted for temporal trends and seasonal variability of prepandemic years. The aim was to estimate the expected number of deaths in a pandemic year for a nonpandemic scenario and the difference in observed and expected deaths aggregated over the year.

RESULTS

In 2020, the number of excess deaths recorded per 100 000 persons was 100 (95% credible interval [CrI], 60 to 135) for Switzerland, 75 (CrI, 40 to 105) for Sweden, and 155 (CrI, 110 to 195) for Spain. In 1918, excess mortality was 6 to 7 times higher. In all 3 countries, the peaks of monthly excess mortality in 2020 were greater than most monthly excess mortality since 1918, including many peaks due to seasonal influenza and heat waves during that period.

LIMITATION

Historical vital statistics might be affected by minor completeness issues before the beginning of the 20th century.

CONCLUSION

In 2020, the COVID-19 pandemic led to the second-largest infection-related mortality disaster in Switzerland, Sweden, and Spain since the beginning of the 20th century.

PRIMARY FUNDING SOURCE

Foundation for Research in Science and the Humanities at the University of Zurich, Swiss National Science Foundation, and National Institute of Allergy and Infectious Diseases.

Impact of omega-3 fatty acid DHA and EPA supplementation in pregnant or breast-feeding women on cognitive performance of children: systematic review and meta-analysis

INTRODUCTION

The omega-3 long-chain polyunsaturated fatty acids docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) are important for brain development and cognitive performance. Because they are semi-essential fatty acids, they must be obtained from food. However, the dietary reference intakes of DHA and EPA have not yet been established. In women, a low DHA and/or EPA serum level during pregnancy or breastfeeding might negatively affect their children. For this study, we conducted a systematic review and meta-analysis of randomized control trials on the association between the consumption of fish oil supplements in pregnant and/or breastfeeding women and the cognitive performance of their children.

METHODS

The PubMed, Embase, and Central literature databases were systematically searched. We included and extracted relevant studies in duplicate and assessed study quality. Cognitive outcomes were grouped according to published criteria and according to time elapsed after the intervention. We performed fixed-effects meta-analyses for each cognitive outcome and for birth weight. We assessed potential confounding with meta-regressions and sensitivity analyses.

RESULTS

A total of 11 trials were included. No significant association was found between DHA/EPA supplementation and any of the assessed cognitive parameters or birth weight.

DISCUSSION

Our results confirm previous reviews on the studied topic. Reasons for inconclusive results may be small sample sizes for each assessed category, questionable quality of included studies, and the difficulty of reliably measuring cognitive performance in small children. Blood levels of omega-3 long-chain polyunsaturated fatty acids were mostly not comparable. Furthermore, the influence of genetic and environmental factors could not be assessed. Studies in this field should address such shortcomings.

National guidelines on nutrient reference values for the healthy adult population and for pregnant or lactating women are based on heterogeneous sources of evidence: review of guidelines

Many countries provide dietary guidelines for health practitioners and/or the general population. However, there is no general, international guideline serving as a template for national dietary guidelines, and there is little to no consensus regarding reference values for different nutrients. The present review compared 27 national dietary guidelines for healthy adults as well as for pregnant and/or breastfeeding women, and analysed their quality and the evidence behind their recommendations. The guidelines were evaluated for their quality using the instrument Agree II, and found to be heterogeneous (overall quality score 14%-100%) and often insufficient (quality score < 50%) due to missing information about their methodology and sources of evidence. We analysed the evidence (number of studies, study types and publication years) of reference values of a number of nutrients using the five guidelines that provided the highest scores in the Agree II assessment. The reference values varied among guidelines, were rarely based on up-to-date meta-analyses, and were often based on insufficiently reported evidence (22/27 guidelines with quality score < 50%). We recommend systematic reviews of high quality studies to formulate future guidelines, and to use guidelines on how to write guidelines.

Management of Home Parenteral Nutrition: Complications and Survival

BACKGROUND AND AIMS

Parenteral nutrition (PN) has become an efficient, safe, and convenient treatment over years for patients suffering from intestinal failure. Home PN (HPN) enables the patients to have a high quality of life in their own environment. The therapy management however implies many restrictions and potentially severe lethal complications. Prevention and therapy of the latter are therefore of utmost importance. This study aims to assess and characterize the situation of patients with HPN focusing on prevalence of catheter-related complications and mortality.

METHODS

Swiss multicentre prospective observational study collecting demographic, anthropometric, and catheter-related data by means of questionnaires every sixth month from 2017 to 2019 (24 months), focusing on survival and complications. Data were analysed using descriptive statistics. Logistic regression models were fitted to investigate association between infection and potential co-factors.

RESULTS

Seventy adult patients (50% women) on HPN were included (≈5 patients/million adult inhabitants/year). The most common underlying diseases were cancer (23%), bariatric surgery (11%), and Crohn's disease (10%). The most prevalent indication was short bowel syndrome (30%). During the study period, 47% of the patients were weaned off PN; mortality rate reached 7% for a median treatment duration of 1.31 years. The rate of catheter-related infection was 0.66/1,000 catheter-days (0.28/catheter-year) while the rate of central venous thrombosis was 0.13/1,000 catheter-days (0.05/catheter-year).

CONCLUSION

This prospective study gives a comprehensive overview of the adult Swiss HPN patient population. The collected data are prerequisite for evaluation, comparison, and improvement of recommendations to ensure best treatment quality and safety.

Public Health Interventions, Epidemic Growth, and Regional Variation of the 1918 Influenza Pandemic Outbreak in a Swiss Canton and Its Greater Regions

Public health interventions implemented during the coronavirus disease 2019 (COVID-19) pandemic are based on experience gained from past pandemics. The 1918 influenza pandemic is the most extensively researched historical influenza outbreak. All 9335 reports available in the State Archives on 121 152 cases of influenza-like illness from the canton of Bern from 473 of 497 municipalities (95.2%) were collected; the cases were registered between 30 June 1918 and 30 June 1919. The overall incidence rates of newly registered cases per week for the 9 greater regions of Bern for both the first and second waves of the pandemic were calculated. Relative incidence rate ratios (RIRRs) were calculated to estimate the change in the slope of incidence curves associated with public health interventions. During the first wave, school closures (RIRR, 0.16 [95% CI, 0.15 to 0.17]) and restrictions of mass gatherings (RIRR, 0.57 [CI, 0.54 to 0.61]) were associated with a deceleration of epidemic growth. During the second wave, in autumn 1918, cantonal authorities initially reacted hesitantly and delegated the responsibility to enact interventions to municipal authorities, which was associated with a lack of containment of the second wave. A premature relaxation of restrictions on mass gatherings was associated with a resurgence of the epidemic (RIRR, 1.18 [CI, 1.12 to 1.25]). Strikingly similar patterns were found in the management of the COVID-19 outbreak in Switzerland, with a considerably higher amplitude and prolonged duration of the second wave and much higher associated rates of hospitalization and mortality.

Heterogeneous contributions of change in population distribution of body mass index to change in obesity and underweight

From 1985 to 2016, the prevalence of underweight decreased, and that of obesity and severe obesity increased, in most regions, with significant variation in the magnitude of these changes across regions. We investigated how much change in mean body mass index (BMI) explains changes in the prevalence of underweight, obesity, and severe obesity in different regions using data from 2896 population-based studies with 187 million participants. Changes in the prevalence of underweight and total obesity, and to a lesser extent severe obesity, are largely driven by shifts in the distribution of BMI, with smaller contributions from changes in the shape of the distribution. In East and Southeast Asia and sub-Saharan Africa, the underweight tail of the BMI distribution was left behind as the distribution shifted. There is a need for policies that address all forms of malnutrition by making healthy foods accessible and affordable, while restricting unhealthy foods through fiscal and regulatory restrictions.

Ultraprocessed Food Consumption is Strongly and Dose-Dependently Associated with Excess Body Weight in Swiss Women

OBJECTIVE

This study investigated the association between ultraprocessed food consumption and excess body weight in a Swiss nationally representative study.

METHODS

Data stem from the cross-sectional Swiss National Nutrition Survey menuCH (n = 2,057). Dietary information was collected with 24-hour dietary recalls, and food items were categorized into non-ultraprocessed or ultraprocessed using the NOVA food classification system. The following three excess body weight indicators were considered: BMI, waist circumference (WC), and a BMI-WC composite outcome. Multinomial logistic regression models stratified by sex were fitted.

RESULTS

Women in the highest quintile of ultraprocessed food weight proportion had significantly higher odds of having obesity (odds ratio [OR] 3.01, 95% CI: 1.48-6.11), having abdominal obesity (OR 2.69, 95% CI: 1.43-5.05), and being in the highest category of the BMI-WC composite outcome (OR 3.28, 95% CI: 1.59-6.77). No relevant associations were observed in men.

CONCLUSIONS

Ultraprocessed food weight proportion was strongly and dose-dependently associated with excess body weight in women but not in men. Further studies are required to elucidate potential mechanisms behind this association. Increasing evidence of the detrimental effect of ultraprocessed food consumption on health stresses the need to consider these products in future public health strategies.

COVID-19 sequelae in adults aged less than 50 years: A systematic review

BACKGROUND

There is emerging evidence of long-term sequelae in a considerable proportion of COVID-19 patients after recovery and the spectrum and severity of such sequelae should be systematically reviewed. This review aims to evaluate the available evidence of all intermediate and long-term COVID-19 sequelae affecting formerly healthy adults.

METHODS

A systematic literature search of Embase, WHO, Scopus, Pubmed, Litcovid, bioRxiv and medRxiv was conducted with a cutoff date of the 17th September 2020 according to PRISMA guidelines and registered in PROSPERO (CRD42020208725). Search terms included "COVID-19", "coronavirus disease 2019", "SARS-CoV-2", "sequelae" and "consequence*". Publications on adult participants, with a confirmed SARS-CoV-2 infection were included. Elderly (>50 years old) and children (<18 years old) were excluded. Bias assessment was performed using a modified Newcastle-Ottawa Scale.

RESULTS

A total of 31 papers were included. Study types included prospective and retrospective cohort studies, cross-sectional studies and case reports. Sequelae persistence since infection spanned 14 days to three months. Sequelae included persistent fatigue (39-73% of assessed persons), breathlessness (39-74%), decrease in quality of life (44-69%), impaired pulmonary function, abnormal CT findings including pulmonary fibrosis (39-83%), evidence of peri-/perimyo-/myocarditis (3-26%), changes in microstructural and functional brain integrity with persistent neurological symptoms (55%), increased incidence of psychiatric diagnoses (5.8% versus 2.5-3.4% in controls), incomplete recovery of olfactory and gustatory dysfunction (33-36% of evaluated persons).

CONCLUSIONS

A variety of organ systems are affected by COVID-19 in the intermediate and longer-term after recovery. Main sequelae include post-infectious fatigue, persistent reduced lung function and carditis. Careful follow-up post COVID 19 is indicated to assess and mitigate possible organ damage and preserve life quality.

Clash of the pandemics - At least 150'000 adults in Switzerland suffer from obesity grades 2 or 3 and are thus at elevated risk for severe COVID-19

Background: Grade 2 and 3 obesity, alongside with other relevant risk factors, are substantially and independently associated with adverse outcomes of coronavirus disease 2019 (COVID-19). However, for Switzerland, due to the lack of synthesis studies, it is currently unknown how many people are affected by obesity at all. This knowledge may help to better estimate the relevance and size of this group at elevated risk, which could be incorporated into strategies to protect risk groups during the still unfolding COVID-19 pandemic. This study aimed to provide a first overall estimation of how many people in Switzerland are currently affected by grade 2 or 3 obesity. Methods: Five representative national population-based studies were accessed which were conducted between 2012 and 2017 and which include data on height and weight of adult men and women in Switzerland. Results: In Switzerland in 2012-2017, among the 11.20% adults who were obese (body mass index (BMI) ≥30.0kg/m2), 1.76% (95% CI 1.50-2.02) suffered from grade 2 obesity (BMI 35.0-39.9 kg/m2), and 0.58% (95% CI 0.50-0.66) from grade severe 3 obesity (BMI ≥40.0 kg/m2). Converted into estimated absolute population numbers, this corresponds to a total of approximately n=154,515 people who suffer from grade 2 or 3 obesity (n=116,216 and n=38,298, respectively). Conclusions: This risk group includes many younger people in Switzerland. The number of people with obesity-related risk becomes 3.8 to 13.6 times higher if grade 1 obesity and overweight people are also included in this risk group, for which there are arguments arising in the latest literature. In general, this large group at risk for severe COVID-19 should be given more attention and support. If it is confirmed that obesity plays a major role in severe COVID-19 courses, then every kilo of body weight that is not gained or that is lost in lockdown counts.

Height and body-mass index trajectories of school-aged children and adolescents from 1985 to 2019 in 200 countries and territories: a pooled analysis of 2181 population-based studies with 65 million participants

BACKGROUND

Comparable global data on health and nutrition of school-aged children and adolescents are scarce. We aimed to estimate age trajectories and time trends in mean height and mean body-mass index (BMI), which measures weight gain beyond what is expected from height gain, for school-aged children and adolescents.

METHODS

For this pooled analysis, we used a database of cardiometabolic risk factors collated by the Non-Communicable Disease Risk Factor Collaboration. We applied a Bayesian hierarchical model to estimate trends from 1985 to 2019 in mean height and mean BMI in 1-year age groups for ages 5-19 years. The model allowed for non-linear changes over time in mean height and mean BMI and for non-linear changes with age of children and adolescents, including periods of rapid growth during adolescence.

FINDINGS

We pooled data from 2181 population-based studies, with measurements of height and weight in 65 million participants in 200 countries and territories. In 2019, we estimated a difference of 20 cm or higher in mean height of 19-year-old adolescents between countries with the tallest populations (the Netherlands, Montenegro, Estonia, and Bosnia and Herzegovina for boys; and the Netherlands, Montenegro, Denmark, and Iceland for girls) and those with the shortest populations (Timor-Leste, Laos, Solomon Islands, and Papua New Guinea for boys; and Guatemala, Bangladesh, Nepal, and Timor-Leste for girls). In the same year, the difference between the highest mean BMI (in Pacific island countries, Kuwait, Bahrain, The Bahamas, Chile, the USA, and New Zealand for both boys and girls and in South Africa for girls) and lowest mean BMI (in India, Bangladesh, Timor-Leste, Ethiopia, and Chad for boys and girls; and in Japan and Romania for girls) was approximately 9-10 kg/m2. In some countries, children aged 5 years started with healthier height or BMI than the global median and, in some cases, as healthy as the best performing countries, but they became progressively less healthy compared with their comparators as they grew older by not growing as tall (eg, boys in Austria and Barbados, and girls in Belgium and Puerto Rico) or gaining too much weight for their height (eg, girls and boys in Kuwait, Bahrain, Fiji, Jamaica, and Mexico; and girls in South Africa and New Zealand). In other countries, growing children overtook the height of their comparators (eg, Latvia, Czech Republic, Morocco, and Iran) or curbed their weight gain (eg, Italy, France, and Croatia) in late childhood and adolescence. When changes in both height and BMI were considered, girls in South Korea, Vietnam, Saudi Arabia, Turkey, and some central Asian countries (eg, Armenia and Azerbaijan), and boys in central and western Europe (eg, Portugal, Denmark, Poland, and Montenegro) had the healthiest changes in anthropometric status over the past 3·5 decades because, compared with children and adolescents in other countries, they had a much larger gain in height than they did in BMI. The unhealthiest changes-gaining too little height, too much weight for their height compared with children in other countries, or both-occurred in many countries in sub-Saharan Africa, New Zealand, and the USA for boys and girls; in Malaysia and some Pacific island nations for boys; and in Mexico for girls.

INTERPRETATION

The height and BMI trajectories over age and time of school-aged children and adolescents are highly variable across countries, which indicates heterogeneous nutritional quality and lifelong health advantages and risks.

FUNDING

Wellcome Trust, AstraZeneca Young Health Programme, EU.

Filling the weight gap: Estimating body weight and BMI using height, chest and upper arm circumference of Swiss conscripts in the first half of the 20th century

We estimate weight and BMI values based on height, chest circumference, and mid upper arm circumference measures of Swiss conscripts in the city of Zurich for each year between 1904 and 1932. Height, chest circumference, and mid upper arm circumference were measured each year from 1904 to 1951. Body weight is available from 1933 to 1951. We used prediction equations from the literature, and also developed our own equations, which we tested and validated on the dataset from 1933 to 1951. We used a representative sample of usually 19-year-old Swiss males (N = 88,792, coverage > 88 %). There was an increase in average height and chest circumference between 1904 and 1951. During both world wars, chest circumference, mid upper arm circumference, weight, and BMI decreased, while height stagnated. Overall mean weight and BMI increased from 1904 to 1951, but decreased during the Great Depression. After World War II, weight quickly returned to the pre-war and pre-Great Depression level, while BMI had not reached the 1933 level by 1951. Average weights of the lower and middle socioeconomic groups were catching up with average weight of the upper socioeconomic group from 1904 to 1951. The convergence in height is less pronounced. Finally, we show that it is possible to accurately predict mean weight and BMI from other anthropometric measurements. We suggest that our estimation approach could be replicated for other historical populations to obtain more information on how nutritional status changed over time.

Residential Altitude Associates With Endurance but Not Muscle Power in Young Swiss Men

Introduction

Physical fitness benefits health. However, there is a research gap on how physical fitness, particularly aerobic endurance capacity and muscle power, is influenced by residential altitude, blood parameters, weight, and other cofactors in a population living at low to moderate altitudes (300–2100 masl).

Materials and Methods

We explored how endurance and muscle power performance changes with residential altitude, Body Mass Index (BMI), hemoglobin and creatinine levels among 108,677 Swiss men aged 18–22 years (covering >90% of Swiss birth cohorts) conscripted to the Swiss Armed Forces between 2007 and 2012. The test battery included a blood test of about 65%, a physical evaluation of about 85%, and the BMI of all conscripts.

Results

Residential altitude was significantly associated with endurance (p < 0.001) but not with muscle power performance (p = 0.858) after adjusting for all available cofactors. Higher BMI showed the greatest negative association with both endurance and muscle power performance. For muscle power performance, the association with creatinine levels was significant. Elevated C-reactive protein (CRP) and hemoglobin levels were stronger contributors in explaining endurance than muscle power performance.

Conclusion

We found a significant association between low to moderate residential altitude and aerobic endurance capacity even after adjustment for hemoglobin, creatinine, BMI and sociodemographic factors. Non-assessed factors such as vitamin D levels, air pollution, and lifestyle aspects may explain the presented remaining association partially and could also be associated with residential altitude. Monitoring the health and fitness of young people and their determinants is important and of practical concern for disease prevention and public health implications.

Impact of World War 1 on placenta weight, birth weight and other anthropometric parameters of neonatal health

BACKGROUND

Wars do not only affect combatant countries, populations in neutral zones can be afflicted by circumjacent conflicts as well, posing a great health burden on mothers and newborns. As neonatal health remains an ongoing cause for concern, identifying determinants that impede fetal growth is crucial. Under this pretext, the study aimed to analyze the impact of World War 1 in the neutral city of Basel on neonatal health by assessing changes in anthropometric parameters.

METHODS

A retrospective analysis of yearly cross sections of term births in the maternity hospital of Basel from 1912 to 1923 was conducted (n = 3718). We tested adjusted anthropometry for time trends in comparison to a pre-war baseline, including birth weight, placenta weight, birth length, ponderal index and gestational age. Interrelations of placenta weights and birth weights were examined separately through birth weight to placenta weight (BW/PW) ratios and residuals of placenta weight to birth weight regressions.

RESULTS

Birth weights, placenta weights and residuals were at their lowest in 1918/19, a trend not reflected in BW/PW ratios. Birth lengths remained low while ponderal indexes declined during the entire period of war, gestational age remained rather stable.

DISCUSSION

1918/19 were the pinnacle years for the population of Basel, who were suffering from general detrimental economic conditions, a food supply crisis and an outbreak of the Spanish Flu. These adverse circumstances coincided with low birth and placenta weights, residuals depicting the correlation of birth weights to placental weights more closely than bw/pw ratios.

Multiple measures derived from 3D photonic body scans improve predictions of fat and muscle mass in young Swiss men

INTRODUCTION

Digital tools like 3D laser-based photonic scanners, which can assess external anthropometric measurements for population based studies, and predict body composition, are gaining in importance. Here we focus on a) systematic deviation between manually determined and scanned standard measurements, b) differences regarding the strength of association between these standard measurements and body composition, and c) improving these predictions of body composition by considering additional scan measurements.

METHODS

We analysed 104 men aged 19-23. Bioelectrical Impedance Analysis was used to estimate whole body fat mass, visceral fat mass and skeletal muscle mass (SMM). For the 3D body scans, an Anthroscan VITUSbodyscan was used to automatically obtain 90 body shape measurements. Manual anthropometric measurements (height, weight, waist circumference) were also taken.

RESULTS

Scanned and manually measured height, waist circumference, waist-to-height-ratio, and BMI were strongly correlated (Spearman Rho>0.96), however we also found systematic differences. When these variables were used to predict body fat or muscle mass, explained variation and prediction standard errors were similar between scanned and manual measurements. The univariable predictions performed well for both visceral fat (r2 up to 0.92) and absolute fat mass (AFM, r2 up to 0.87) but not for SMM (r2 up to 0.54). Of the 90 body scanner measures used in the multivariable prediction models, belly circumference and middle hip circumference were the most important predictors of body fat content. Stepwise forward model selection using the AIC criterion showed that the best predictive power (r2 up to 0.99) was achieved with models including 49 scanner measurements.

CONCLUSION

The use of a 3D full body scanner produced results that strongly correlate to manually measured anthropometric measures. Predictions were improved substantially by including multiple measurements, which can only be obtained with a 3D body scanner, in the models.

Fish consumption is associated with school performance in children in a non-linear way: Results from the German cohort study KiGGS

Introduction

How the long-chain fatty acids docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) in the diet permitted human brain evolution, and how much our brains need today to function optimally are still hot topics for debate. DHA and EPA are considered as semi-essential because only insufficient amounts can be produced from other nutrients, such that they must be ingested with the diet. However, the Dietary Reference Intake of DHA and EPA, or of fish containing these fatty acids, has not yet been established. Eating fish is often recommended and generally considered beneficial for health and cognitive development in children and adolescents. For this study, data from a large cohort study were analysed to assess the association between fish consumption and cognitive school performance in children and adolescents.

Methods

Data from the German cohort of children and adolescent health KiGGS, which was conducted 2003-06 and included more than 17 000 children, were analysed. Ordered logistic regressions were performed to test for associations between fish intake and school performance. Potential confounders were included in the models.

Results

A statistically significant association was found between an intake of 8 g of fish per day and the probability of increasing the final grade in German [odds ratio (OR) 1.193, 95% confidence interval (CI) 1.049-1.358] and mathematics (OR 1.16, 95% CI 1.022-1.317) by one point, compared to no or very limited fish consumption. For the outcome German, higher levels of fish intake also showed a positive effect. These relationships were not linear but tended to decrease again at higher doses of fish.

Discussion

Our result confirms previous reports of a positive association between fish intake and school performance. Interestingly, this relationship was not linear but tended to decrease again in the highest categories of fish intake. We hypothesize that mercury or other pollutants in the fish could be detrimental at high levels. As only half of all children met the minimal fish intake recommendations, fish consumption should be promoted more strongly in children to meet the minimal requirements of long-chain polyunsaturated fatty acids.

Lay Summary

Polyunsaturated fatty acids like DHA and EPA that are present in fish are essential for a healthy human brain development. We found a U-shaped association between fish intake and school performance in children. We hypothesize that mercury or other pollutants in the fish could be detrimental at high intake levels.

Body height and waist circumference of young Swiss men as assessed by 3D laser-based photonic scans and by manual anthropometric measurements

Overweight and obesity are considered among the major health concerns worldwide. The body mass index is a frequently used measure for overweight and obesity and is associated with common non-communicable diseases such as diabetes type II, cardiovascular diseases and certain cancers. However, the body mass index does not account for the distribution of body fat and relative fat to muscle mass. 3D laser-based photonic full body scans provide detailed information on various body circumferences, surfaces, and volumes as well as body height and weight (using an integrated scale). In the literature, body scans showed good feasibility, reliability, and validity, while also demonstrating a good correlation with health parameters linked to the metabolic syndrome. However, systematic differences between body scan derived measurements and manual measurements remain an issue. This study aimed to assess these systematic differences for body height, waist circumference, and body mass index using cross-sectional data from a homogenous sample of 52 young Swiss male volunteers. In addition to 3D laser-based photonic full body scans and correlative manual measurements, body fat distribution was assessed through bioelectrical impedance analysis. Overall, an excellent correlation was found between measurements of waist circumference and body mass index, and good correlation between body mass index and total fat mass, as well as between waist circumference and visceral fat mass as assessed by bioelectrical impedance analysis. Volunteers were shorter in height measured by body scan when compared to manual measurements. This systematic difference became smaller when volunteers stood in the scanner in a completely upright position with their feet together. Waist circumference was slightly smaller for manual measurements than for body scan derived values. This systematic difference was larger in overweight volunteers compared to leaner volunteers.

Influence of network properties on a migration induced secular height trend by Monte Carlo simulation

Background: Recent research reported height biased migration of taller individuals and a Monte Carlo simulation showed that such preferential migration of taller individuals into network hubs can induce a secular trend of height. In the simulation model taller agents in the hubs raise the overall height of all individuals in the network by a community effect. However, it could be seen that the actual network structure influences the strength of this effect. In this paper the background and the influence of the network structure on the strength of the secular trend by migration is investigated. Material and methods: Three principal network types are analyzed: networks derived from street connections in Switzerland, more regular fishing net like networks and randomly generated ones. Our networks have between 10 and 152 nodes and between 20 and 307 edges connecting the nodes. Depending on the network size between 5.000 and 90.000 agents with an average height of 170cm (SD 6.5cm) are initially released into the network. In each iteration new agents are regenerated based on the actual average body height of the previous iteration and, to a certain proportion, corrected by body heights in the neighboring nodes. After generating new agents, a certain number of them migrated into neighbor nodes, the model let preferentially taller agents migrate into network hubs. Migration is balanced by back migration of the same number of agents from nodes with high centrality measures to less connected nodes. The latter is random as well, but not biased by the agents height. Furthermore the distribution of agents per node and their correlation to the centrality of the nodes is varied in a systematic manner. After 100 iterations, the secular trend, i.e. the gain in body height for the different networks, is investigated in relation to the network properties. Results: We observe an increase of average agent body height after 100 iterations if height biased migration is enabled. The increase rate depends on the height of the neighboring factor, the population distribution, the relationship between population in the nodes and their centrality as well as on the network topology. Networks with uniform like distributions of the agents in the nodes, uncorrelated associations between node centrality and agent number per node, as well as very heterogeneous networks with very different node centralities lead to biggest gains in average body height. Conclusion: Our simulations show, that height biased migration into network hubs can possibly contribute to the secular trend of height increase in the human population. The strength of this "tall by migration" event depends on the actual properties of the underlying network. There is a possible significance of this mechanism for social networks, when hubs are represented by individuals and edges as their personal relationships. However, the required high number of iterations to achieve significant effects in more natural network structures in our models requires further studies to test the relevance and real effect sizes in real world scenarios.

Mindful eating and common diet programs lower body weight similarly: Systematic review and meta-analysis

Common strategies for reducing body weight rely on limiting energy intake and restricting food choices. However, these strategies have often been proven ineffective in achieving long-term and sustainable weight reduction. More recently, mindful eating as an alternative weight management strategy has gained increasing attention, yet systematic reviews on intuitive or mindful eating published so far present contradictory results. We performed a systematic review and meta-analysis on randomized controlled trials on weight loss programs based on mindful or intuitive eating. We analyzed results using meta-regressions. We included a total of 10 studies and found a significant weight loss effect of mindful/intuitive eating strategies compared with nonintervention controls (-0.348 kg, 95% CI: -0.591 to -0.105, P = 0.005). However, there was no difference compared with conventional diet programs (P = 0.99). Reduction of BMI (-0.137 kg/m² , 95% CI: -0.365 to 0.091, P = 0.240) or waist circumference (-0.358 cm, 95% CI: -0.916 to 0.200, P = 0.209) were not statistically significant. Mindful/intuitive eating could be a practical approach to weight control. Limitations of this study include the unbalanced sex, origin, place of residence of the participants, and the short duration of interventions. Future research should aim at investigating long-term effects and include a more heterogeneous study population.

Changes in Biological Pathways During 6,000 Years of Civilization in Europe

The beginning of civilization was a turning point in human evolution. With increasing separation from the natural environment, mankind stimulated new adaptive reactions in response to new environmental factors. In this paper, we describe direct signs of these reactions in the European population during the past 6,000 years. By comparing whole-genome data between Late Neolithic/Bronze Age individuals and modern Europeans, we revealed biological pathways that are significantly differently enriched in nonsynonymous single nucleotide polymorphisms in these two groups and which therefore could be shaped by cultural practices during the past six millennia. They include metabolic transformations, immune response, signal transduction, physical activity, sensory perception, reproduction, and cognitive functions. We demonstrated that these processes were influenced by different types of natural selection. We believe that our study opens new perspectives for more detailed investigations about when and how civilization has been modifying human genomes.

Have Swiss adult males and females stopped growing taller? Evidence from the population-based nutrition survey menuCH, 2014/2015

Data from the National Nutrition Survey for adults (menuCH) allow for the assessment of recent trends in measured height by year of birth for adult men and women from a population-based sample. The aim of the present study was to test if - similarly to conscripts and schoolchildren - the Swiss adult population stopped growing taller in recent birth cohorts, and if so, when the change occurred. We found that - when self-reported - height was overestimated on average by about 1 cm in both men and women, with an increasing tendency with older age and with shorter height. Average measured height increased by 4.5-5.0 cm for adult men and women between the birth years 1937-1949 and 1990-1995. However, this increase was not linear, and starting with the 1970s birth years, average height plateaued on a level of about 178 cm for men and 166 cm for women. Being born outside of Switzerland or adjustment for potential shrinkage with increasing age did not change this temporal pattern. We also found shorter average height among participants from the Italian part of Switzerland and those with lower educational level. It remains unclear if the phenomenon of stabilisation affects all subgroups of the Swiss population. Future studies should combine a larger number of population-based surveys to enhance the sample size, for example, for people with a migration background or with different educational levels. Continuing growth monitoring needs to be performed to assess if environmental and demographic changes with an impact on body growth (adverse trends in nutrition, increasing social inequality in health, ethnic composition of the population) positively or negatively influence future trends in average height.

Spatial Association of Food Sales in Supermarkets with the Mean BMI of Young Men: An Ecological Study

Supermarket food sales data might serve as a simple indicator of population-level dietary habits that influence the prevalence of excess weight in local environments. To test this possibility, we investigated how variation in store-level food sales composition across Switzerland is associated with the mean Body Mass Index (BMI) of young men (Swiss Army conscripts) living near the stores. We obtained data on annual food sales (2011) for 553 stores from the largest supermarket chain in Switzerland, identified foods commonly regarded as “healthy” or “unhealthy” based on nutrient content, and determined their contribution to each store’s total sales (Swiss francs). We found that the sales percentages of both “healthy” and “unhealthy” food types varied by 2- to 3-fold among stores. Their balance ranged from −15.3% to 18.0% of total sales; it was positively associated with area-based socioeconomic position (r = 0.63) and negatively associated with the mean BMI of young men in the area (r = −0.42). Thus, even though we compared supermarkets from a single chain, different shopping behaviors of customers caused stores in privileged areas to sell relatively more healthy food. Knowledge about such patterns could help in designing in-store interventions for healthier nutrition and monitoring their effects over time.

Development of physical fitness performance in young Swiss men from 2006 to 2015

From 1980 to 2000, physical fitness decreased and body mass index (BMI) increased in the population of many industrialized countries. Little is known about these trends after the year 2000. This study aimed to investigate physical fitness performance, physical activity (PA) behavior, and BMI of young, male Swiss adults between 2006 and 2015. For this purpose, results from the Swiss Armed Forces mandatory recruitment were used. A total of 306 746 male conscripts provided complete fitness test data, mean ± SD (range from 5th to 95th percentile): 20 ± 1 (18‐21) years, 178 ± 7 (168‐189) cm; 74 ± 13 (58‐97) kg, predicted maximal oxygen consumption of 49.9 ± 4.6 (41.8‐56.9) mL/kg/min (Conconi test), 125 ± 58 (43‐232) seconds in trunk muscle strength test (prone bridge), 2.31 ± 0.24 (1.90‐2.66) m in standing long jump, 6.46 ± 0.73 (5.30‐7.70) m in seated shot put (2 kg medical‐ball shot) and 45.6 ± 12.2 (29.9‐66.7) seconds in one‐leg standing test (sum of both legs; eyes closed after 10 seconds and head tilted back after 20 seconds). In the investigated population, 73.8% fulfilled basic PA recommendations, 46.2% were classified as regularly vigorously active. Performances in aerobic endurance and muscle power did not show secular changes over time. However, core stability performance and PA behavior increased, while balance ability decreased over this 10‐year period. Average BMI increased by 2.0% between 2006 and 2010 and did not change thereafter. Male Swiss adults are at least as physically fit as they were a decade ago. The secular trends of decreasing physical performances and increasing BMI have stopped, and self‐reported sport participation and leisure time PA have been increased in the observed population over the last 10 years.

Associations between anthropometric indices, blood pressure and physical fitness performance in young Swiss men: a cross-sectional study

OBJECTIVES

To assess the benefit of waist circumference (WC) measurements during routine conscription medical examination in two military conscription centres in Switzerland. We compared the prevalence of overweight and obesity assessed by body mass index (BMI) with the prevalence of elevated disease risks assessed by WC and waist-to-height ratio (WHtR). We investigated how these measures were associated with systolic blood pressure, physical fitness performance and socioeconomic determinants.

DESIGN

Cross-sectional survey.

SETTING

Two Swiss conscription centres in 2016.

PARTICIPANTS

1548 Swiss male conscripts, 18-22 years old.

MAIN OUTCOME

Prevalences of elevated WC, WHtR and BMI values according to WHO categories. Secondary outcomes include systolic blood pressure, physical fitness performance and endurance performance.

RESULTS

Using BMI cut-points, 25.0% of all conscripts were overweight or obese. When applying WC cut-points, 9.2% had an increased disease risk, while 14.8% of the conscripts were at risk using WHtR cut-points. In the BMI range of 25.0-27.4 kg/m², 3.6% showed an increased disease risk when using WC and 24.6% when using WHtR cut-points. Of the conscripts with a BMI of 27.5-29.9 kg/m², 72.4% had an increased disease risk using WHtR, and 42.5% when using WC cut-points. Determinants of elevated BMI, WC and WHtR were low occupational status, rural residential area, older age and location in central and Northwest Switzerland. Systolic blood pressure increased with increasing BMI, WC and WHtR. Physical fitness and endurance test performances decreased with increasing BMI, WC and WHtR.

CONCLUSION

In addition to BMI, WC and WHtR add relevant information to the health assessment of young men. However, the prevalence of overweight/increased health risk differed when using BMI, WC or WHtR. Further studies should include measures of body composition to test whether these differences arise from muscular young men within the overweight BMI range, who had a normal WC.

Ladies first: Female and male adult height in Switzerland, 1770-1930

When investigating the well-being of a society, the living conditions of females are of special importance, not only due to the immediate impact for those directly involved, but also because of the potential intergenerational effects. Studying the dimorphism in the mean height helps to depict variation in the basic biological sex difference due to gender-related factors that potentially determine net nutrition. To expand knowledge of diachronic development in Swiss well-being conditions we investigate changes in the height of adult females born 1770-1930, and compare the series with data on contemporary males from the same sources: We employ a sample of N = 21'028 women and N = 21'329 men from passport-, convict-, maternity hospital-, and voluntary World War II army auxiliary records. The secular height trend is found both in males, from the 1870s/1880s, and in females starting with the 1840s/1850s birth cohorts. During the decades under study, mean height increased from 157 cm to 164 cm in female and 167 cm to 172 cm in male passport applicants, 154 cm to 159 cm in female and 167 cm to 169 cm in male convicts, 159 cm to 163 cm in female auxiliaries, and 155 cm to 159 cm in females giving birth in the maternity hospital of Basel. Because females seem to have started the secular trend in height earlier than their male contemporaries, the height dimorphism decreased during the second half of the 19th century. Differences between socio-economic status (SES) and data sources are found in both females and males: Women with low SES were significantly shorter than those of the other SES groups in all sources (on average 1.40 cm, p-values between 0.00 and 0.03). In men we found individuals of upper SES to be significantly taller (on average 1.96 cm, p-value = 0.00-0.10). Concerning differences between the sources, overall, passport applicants were the tallest for men as well as women; in females the individuals measured at the maternity hospital and in prison were the shortest. The variances across the datasets highlight the importance of considering different sources to depict average living conditions. Noteworthy is the finding that the diverse sources under study all show the same trajectory of increasing mean height over the course of the 19th century. In the long run, the improving net nutritional status of Swiss females may have been one of the contributors behind the general rise in well-being of the country's population from the later 19th century onwards.

Increasing variability of body mass and health correlates in Swiss conscripts, a possible role of relaxed natural selection?

BACKGROUND AND OBJECTIVES

The body mass index (BMI) is an established anthropometric index for the development of obesity-related conditions. However, little is known about the distribution of BMI within a population, especially about this distribution's temporal change. Here, we analysed changes in the distribution of height, weight and BMI over the past 140 years based on data of Swiss conscripts and tested for correlations between anthropometric data and standard blood parameters.

METHODS

Height and weight were measured in 59 504 young Swiss males aged 18-19 years during conscription in 1875-79, 1932-36, 1994 and 2010-12. For 65% of conscripts in 2010-12, results of standard blood analysis were available. We calculated descriptive statistics of the distribution of height, weight and BMI over the four time periods and tested for associations between BMI and metabolic parameters.

RESULTS

Average and median body height, body weight and BMI increased over time. Height did no longer increase between 1994 and 2010-12, while weight and BMI still increased over these two decades. Variability ranges of weight and BMI increased over time, while variation of body height remained constant. Elevated levels of metabolic and inflammatory blood parameters were found at both ends of BMI distribution.

CONCLUSIONS AND IMPLICATIONS

Both overweight and underweight subgroups showed similar changes in inflammation parameters, pointing toward related metabolic deficiencies in both conditions. In addition to environmental influences, our results indicate a potential role of relaxed natural selection on genes affecting metabolism and body composition.

Worldwide trends in body-mass index, underweight, overweight, and obesity from 1975 to 2016: a pooled analysis of 2416 population-based measurement studies in 128·9 million children, adolescents, and adults

BACKGROUND

Underweight, overweight, and obesity in childhood and adolescence are associated with adverse health consequences throughout the life-course. Our aim was to estimate worldwide trends in mean body-mass index (BMI) and a comprehensive set of BMI categories that cover underweight to obesity in children and adolescents, and to compare trends with those of adults.

METHODS

We pooled 2416 population-based studies with measurements of height and weight on 128·9 million participants aged 5 years and older, including 31·5 million aged 5-19 years. We used a Bayesian hierarchical model to estimate trends from 1975 to 2016 in 200 countries for mean BMI and for prevalence of BMI in the following categories for children and adolescents aged 5-19 years: more than 2 SD below the median of the WHO growth reference for children and adolescents (referred to as moderate and severe underweight hereafter), 2 SD to more than 1 SD below the median (mild underweight), 1 SD below the median to 1 SD above the median (healthy weight), more than 1 SD to 2 SD above the median (overweight but not obese), and more than 2 SD above the median (obesity).

FINDINGS

Regional change in age-standardised mean BMI in girls from 1975 to 2016 ranged from virtually no change (-0·01 kg/m2 per decade; 95% credible interval -0·42 to 0·39, posterior probability [PP] of the observed decrease being a true decrease=0·5098) in eastern Europe to an increase of 1·00 kg/m2 per decade (0·69-1·35, PP>0·9999) in central Latin America and an increase of 0·95 kg/m2 per decade (0·64-1·25, PP>0·9999) in Polynesia and Micronesia. The range for boys was from a non-significant increase of 0·09 kg/m2 per decade (-0·33 to 0·49, PP=0·6926) in eastern Europe to an increase of 0·77 kg/m2 per decade (0·50-1·06, PP>0·9999) in Polynesia and Micronesia. Trends in mean BMI have recently flattened in northwestern Europe and the high-income English-speaking and Asia-Pacific regions for both sexes, southwestern Europe for boys, and central and Andean Latin America for girls. By contrast, the rise in BMI has accelerated in east and south Asia for both sexes, and southeast Asia for boys. Global age-standardised prevalence of obesity increased from 0·7% (0·4-1·2) in 1975 to 5·6% (4·8-6·5) in 2016 in girls, and from 0·9% (0·5-1·3) in 1975 to 7·8% (6·7-9·1) in 2016 in boys; the prevalence of moderate and severe underweight decreased from 9·2% (6·0-12·9) in 1975 to 8·4% (6·8-10·1) in 2016 in girls and from 14·8% (10·4-19·5) in 1975 to 12·4% (10·3-14·5) in 2016 in boys. Prevalence of moderate and severe underweight was highest in India, at 22·7% (16·7-29·6) among girls and 30·7% (23·5-38·0) among boys. Prevalence of obesity was more than 30% in girls in Nauru, the Cook Islands, and Palau; and boys in the Cook Islands, Nauru, Palau, Niue, and American Samoa in 2016. Prevalence of obesity was about 20% or more in several countries in Polynesia and Micronesia, the Middle East and north Africa, the Caribbean, and the USA. In 2016, 75 (44-117) million girls and 117 (70-178) million boys worldwide were moderately or severely underweight. In the same year, 50 (24-89) million girls and 74 (39-125) million boys worldwide were obese.

INTERPRETATION

The rising trends in children's and adolescents' BMI have plateaued in many high-income countries, albeit at high levels, but have accelerated in parts of Asia, with trends no longer correlated with those of adults.

FUNDING

Wellcome Trust, AstraZeneca Young Health Programme.

Individual development and potential determinants of excess weight in children and adolescents: a longitudinal study

OBJECTIVES

Excess body weight is a major public health concern already at a young age. The aim of this study was to track weight status among pupils aged 6-14 years in the City of Zurich, to examine the association between sociodemographic and environmental factors and excess weight at school entry and excess weight gain thereafter.

DESIGN

Longitudinal study.

SETTING

Data were from the medical examinations routinely performed at public schools in Zurich, the largest city in Switzerland. Weight and height were measured in kindergarten (mean age: 5.9 years), grade 1 (7.2 years), grade 4 (10.1 years) and grade 8 (14.2 years).

PARTICIPANTS

The study included 7145 children who enrolled in kindergarten in 2003/04 or 2004/05 and had more than one measurement of weight and height.

OUTCOME MEASURES

Body weight and height were measured by physicians or nurses during the medical examinations at schools. For each measurement point, body mass index (BMI) was calculated and converted to the age- and sex-specific BMI z-scores and BMI percentiles. The stability of children's weight status categories, sociodemographic and environmental factors associated with excess weight gain and with overweight/obesity at school entry were investigated using multiple linear and logistic regression models.

RESULTS

The prevalence of overweight/obesity increased between kindergarten and grade 8 (from 17.6 to 26.0%). Overall, 86.2% of the children remained in the same weight category; 10.8% shifted to a higher and 3% to a lower category. There was a strong correlation between migration background and overweight/obesity at school entry (odds ratios between 1.62 and 3.42, all p <0.05). In addition, boys with Southern/Eastern European background (+2.29 BMI percentile, p = 0.023) and girls in lower level school type (+12.98 BMI percentile, p <0.001) had the highest risk for excess weight gain over a school period.

CONCLUSIONS

Overweight/obesity developed prior to school entry and mostly persisted through childhood. In order to better exploit obesity prevention potential, measures to prevent the development of the excess weight need to be implemented at a very early stage in life.

Body height and mortality - mortality follow-up of four Swiss surveys

BACKGROUND

Adult body height is largely determined by genetics, but also by dietary factors, which in turn depend on socioeconomic status and lifestyle. We examined the association between adult body height and mortality in Switzerland, a country with three main language regions with different cultural background.

METHODS

We included 16,831 men and 18,654 women, who participated in Swiss population-based health surveys conducted 1977-1993 and who were followed up until end of 2008. Multivariable Cox proportional hazards models were computed to examine the association of body height with overall, cardiovascular, and cancer mortality.

RESULTS

We observed a positive association between adult body height and all-cause mortality in women (HR=1.34, 95% CI 1.10-1.62, tallest vs. average women). In men, mortality risk decreased with increasing height, with shortest men tending to have higher (1.06, 0.94-1.19) and tallest men a lower (0.94, 0.77-1.14) risk compared with men of average height (p-trend 0.0001). Body height was associated with cancer mortality in women, such that tallest women had a higher risk of dying from cancer than women of average height (1.37, 1.02-1.84), but there was no such association in men (0.95, 0.69-1.30). In both sexes, height was not associated with cardiovascular mortality in a statistically significant manner.

CONCLUSION

Our study does not support an inverse association of body height with all-cause mortality. On the contrary, our data suggests a higher overall risk in taller women, mainly driven by a positive association between body height and cancer mortality.