Seasonal variations in growth and body composition of 8–11-y-old Danish children

Dalskov, Stine-Mathilde; Ritz, Christian; Larnkjær, Anni; Damsgaard, Camilla T.; Petersen, Randi; Sørensen, Louise Bergmann; Hjorth, Mads F.; Ong, Ken K.; Astrup, Arne; Mølgaard, Christian; Michaelsen, Kim F.

doi:10.1038/pr.2015.206

Cited by 21 publications

(16 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…One test for the physiological relevance of the seasonal changes is to ask whether the coordinated effector hormone peak in winter/spring correlates with a time of high setpoint for reproduction, metabolism, stress adaptation, and growth in humans. This relates favorably to observations on a winter-spring peak of human growth rate (Gelander, Karlberg & Albertsson, 1994;Land et al, 2005;Dalskov et al, 2016), cognitive functions (Meyer et al, 2016), immune functions (Dopico et al, 2015) and sperm quality (De Giorgi et al, 2015; Levitas 2013). Human fecundity also peaks in winter-spring in Israel and other countries in similar clines (Roenneberg and Aschof, 1990), and shifts to later in the year at higher latitudes.…”

Section: Discussionsupporting

confidence: 78%

Human hormone seasonality

Tendler

Bär

Mendelsohn-Cohen

et al. 2020

Preprint

View full text Add to dashboard Cite

Hormones control the major biological functions of stress response, growth, metabolism and reproduction. In animals these hormones show pronounced seasonality, with different set-points for different seasons. In humans, the seasonality of these hormones remains unclear, due to a lack of datasets large enough to discern common patterns and cover all hormones. Here, we analyze an Israeli health record on 46 million person-years, including millions of hormone blood tests. We find clear seasonal patterns: the effector hormones peak in winter-spring, whereas most of their upstream regulating pituitary hormones peak only months later, in summer. This delay of months is unexpected because known delays in the hormone circuits last hours. We explain the precise delays and amplitudes by proposing and testing a mechanism for the circannual clock: the gland masses grow with a timescale of months due to trophic effects of the hormones, generating a feedback circuit with a natural frequency of about a year that can entrain to the seasons. Thus, humans may show coordinated seasonal set-points with a winter-spring peak in the growth, stress, metabolism and reproduction axes.

show abstract

Section: Discussionsupporting

confidence: 78%

Human hormone seasonality

Tendler

Bär

Mendelsohn-Cohen

et al. 2020

Preprint

View full text Add to dashboard Cite

show abstract

“…This pattern was not readily apparent in prior studies where few BMI measures were available . It differed somewhat from recent studies in southern Wisconsin and Denmark, where BMI increases appeared flatter or nearer to linear during the school months. We also observed an unexpected mid‐winter nadir in BMI z‐scores.…”

Section: Discussioncontrasting

confidence: 92%

Circannual growth in Wisconsin children and adolescents: Identifying optimal periods of obesity prevention

et al. 2019

View full text Add to dashboard Cite

Summary Background Recent studies suggest kids tend to gain the most weight in summer, but schools are chastised for supporting obesogenic environments. Conclusions on circannual weight gain are hampered by infrequent body mass index (BMI) measurements, and guidance is limited on the optimal timeframe for paediatric weight interventions. Objectives This study characterized circannual trends in BMI in Wisconsin children and adolescents and identified sociodemographic differences in excess weight gain. Methods An observational study was used to pool data from 2010 to 2015 to examine circannual BMI z‐score trends for Marshfield Clinic patients age 3 to 17 years. Daily 0.20, 0.50, and 0.80 quantiles of BMI z‐score were estimated, stratified by gender, race, and age. Results BMI z‐scores increased July to September, followed by a decrease in October to December, and another increase to decrease cycle beginning in February. For adolescents, the summer increase in BMI was greater among those in the upper BMI z‐score quantile relative to those in the lower quantile (+0.15 units vs +0.04 units). This pattern was opposite in children. Conclusions BMI increased most rapidly in late summer. This growth persisted through autumn in adolescents who were larger, suggesting weight management support may be beneficial for kids who are overweight at the start of the school year.

show abstract

“…It is generally accepted that height velocity in childhood is greatest during the summer, and slightest during the winter [232223]. There are also reports that height velocity in Japanese children was greater in summer than in winter [2425].…”

Section: Discussionmentioning

confidence: 99%

Chronobiological Hypothesis about the Association Between Height Growth Seasonality and Geographical Differences in Body Height According to Effective Day Length

Yokoya

Higuchi

2016

J Circadian Rhythms

View full text Add to dashboard Cite

Studies on growth hormone therapy in children have shown that height velocity is greater in summer than in winter and that this difference increases with latitude. It is hypothesized that summer daylight is a causative factor and that geographical distribution of body height will approximate the distribution of summer day length over time. This is an ecological analysis of prefecture-level data on the height of Japanese youth. Mesh climatic data of effective day length were collated. While height velocity was greatest during the summer, the height of Japanese youth was strongly and negatively correlated with the distribution of winter effective day length. Therefore, it is anticipated that summer height velocity is greater according to winter day length (dark period). This may be due to epigenetic modifications, involving reversible DNA methylation and thyroid hormone regulation found in the reproductive system of seasonal breeding vertebrates. If the function is applicable to humans, summer height growth may quantitatively increase with winter day length, and height growth seasonality can be explained by thyroid hormone activities that-induced by DNA methylation-change depending on the seasonal difference in day length. Moreover, geographical differences in body height may be caused by geographical differences in effective day length, which could influence melatonin secretion among subjects who spend a significant time indoors.

show abstract

Seasonal variations in growth and body composition of 8–11-y-old Danish children

Cited by 21 publications

References 33 publications

Human hormone seasonality

Human hormone seasonality

Circannual growth in Wisconsin children and adolescents: Identifying optimal periods of obesity prevention

Chronobiological Hypothesis about the Association Between Height Growth Seasonality and Geographical Differences in Body Height According to Effective Day Length

Contact Info

Product

Resources

About