The association between being breastfed in infancy and risks of cancer in adulthood-a UK Biobank study.

Background: Being breastfed has established benefits for infant health, but its long-term effects on adult diseases, including cancer, remain underexplored. We examined associations between being breastfed in infancy and the risks of common cancers.

Methods: Data from 339,115 participants (191,117 women) enrolled in the UK Biobank with self-reported breastfeeding data were linked to national cancer registries.

Developmental origins of exceptional health and survival: A four-generation family cohort study.

Background: Previous researched has demonstrated potent health and survival advantages across three-generations in longevity-enriched families. However, the survival advantage associated with familial longevity may manifest earlier in life than previously thought.

Methods: We conducted a matched cohort study comparing early health trajectories in third-generation grandchildren (n = 5,637) and fourth-generation great-grandchildren (n = 14,908) of longevity-enriched sibships to demographically matched births (n = 41,090) in Denmark between 1973 and 2018.

Early life body size and puberty markers as predictors of breast cancer risk later in life: A neural network analysis.

Background: The early life factors of birthweight, child weight, height, body mass index (BMI) and pubertal timing are associated with risks of breast cancer. However, the predictive value of these factors in relation to breast cancer is largely unknown. Therefore, using a machine learning approach, we examined whether birthweight, childhood weights, heights, BMIs, and pubertal timing individually and in combination were predictive of breast cancer.

Trajectories of body mass index across the lifecourse and associations with post-menopausal breast cancer by estrogen receptor status.

Background: Associations between a high body mass index (BMI) at single timepoints during child- and adulthood and risks of post-menopausal breast cancer are well-established, but associations with BMI across the lifecourse remains largely unknown. Therefore, we examined whether lifecourse BMI trajectories were associated with risks of post-menopausal breast cancer overall and by estrogen receptor (ER) status.

Methods: We included 6698 Danish women born 1930-1946.

Heritability and circulating concentrations of pregnancy-associated plasma protein-A and stanniocalcin-2 in elderly monozygotic and dizygotic twins.

Introduction: Pregnancy-associated plasma protein-A (PAPP-A) is an IGF-activating enzyme suggested to influence aging-related diseases. However, knowledge on serum PAPP-A concentration and regulation in elderly subjects is limited. Therefore, we measured serum PAPP-A in elderly same-sex monozygotic (MZ) and dizygotic (DZ) twins, as this allowed us to describe the age-relationship of PAPP-A, and to test the hypothesis that serum PAPP-A concentrations are genetically determined.

Association of Trauma With Long-Term Risk of Death and Immune-Mediated or Cancer Disease in Same-Sex Twins.

Importance: Immediate consequences of trauma include a rapid and immense activation of the immune system, whereas long-term outcomes include premature death, physical disability, and reduced workability.

Objective: To investigate if moderate to severe trauma is associated with long-term increased risk of death or immune-mediated or cancer disease.

Design, Setting, And Participants: This registry-based, matched, co-twin control cohort study linked the Danish Twin Registry and the Danish National Patient Registry to identify twin pairs in which 1 twin had been exposed to severe trauma and the other twin had not from 1994 to 2018.

The association between skeletal lesions and tuberculosis in a pre-antibiotic South African sample.

Objective: This study assessed the sensitivity and specificity of skeletal lesions to accurately diagnose TB in a pre-antibiotic South African skeletal sample.

Materials: A total of 435 skeletons of individuals who died before 1950 from the Raymond A. Dart Collection of Human Skeletons.

Birthweight, childhood body size, and timing of puberty and risks of breast cancer by menopausal status and tumor receptor subtypes.

Background: Associations of birthweight, childhood body size and pubertal timing with breast cancer risks by menopausal status and tumor receptor subtypes are inconclusive. Thus, we investigated these associations in a population-based cohort of Danish women.

Methods: We studied 162,419 women born between 1930 and 1996 from the Copenhagen School Health Records Register.

Reassessing the evidence of a survival advantage in Type 2 diabetes treated with metformin compared with controls without diabetes: a retrospective cohort study.

Background: Previous research has suggested that individuals with Type 2 diabetes and initiated on metformin monotherapy present with a survival advantage compared with the general population without diabetes. This finding has generated considerable interest in the prophylactic use of metformin against age-related morbidity.

Methods: Utilizing Danish National Health Registers, we assessed differences in survival associated with metformin monotherapy for Type 2 diabetes compared with no diagnosis of diabetes in both singleton and discordant twin populations between 1996 and 2012.

Early life body size, pubertal timing, and risks of benign breast disease in a large cohort of Danish female adolescents and women.

A high childhood body mass index (BMI) may be protective against benign breast disease (BBD), but little is known about the effects of other early life body size measures. Thus, we examined associations between birthweight, childhood BMI, height, and pubertal timing and BBD risks. We included 171,272 girls, born from 1930 to 1996, from the Copenhagen School Health Records Register, which contains information on birthweight, childhood anthropometry (7-13 years), age at onset of the growth spurt (OGS), and peak height velocity (PHV).

Genetic contribution to the etiology of Achilles tendon rupture. A Danish nationwide register study of twins.

Background: It is unknown if genetics contribute to the etiology of acute Achilles tendon rupture (ATR). The aims of the present study were, 1) To calculate the concordance rate for monozygotic (MZ) twins and same-sex dizygotic (SSDZ) twins and 2) to estimate the heritability of ATR.

Methods: The study was performed as a registry study using the Danish Twin Registry and the Danish National Patient Registry.

Associations of maternal birth weight, childhood height, BMI, and change in height and BMI from childhood to pregnancy with risks of preterm delivery.

Background: It remains unknown whether maternal early life body size and changes in height and BMI from childhood to pregnancy are associated with risks of having a preterm delivery.

Objectives: We investigated whether a woman's birth weight, childhood height, BMI, and changes in height and BMI from childhood to pregnancy were associated with preterm delivery.

Methods: We studied 47,947 nulliparous women born from 1940 to 1996 who were included in the Copenhagen School Health Records Register with information on birth weight and childhood heights and weights at ages 7 and/or 13 years.

Leprosy in medieval Denmark: Exploring life histories through a multi-tissue and multi-isotopic approach.

Objectives: By focusing on two Danish leprosaria (Naestved and Odense; 13th-16th c. CE) and using diet and origin as proxies, we follow a multi-isotopic approach to reconstruct life histories of patients and investigate how leprosy affected both institutionalized individuals and the medieval Danish community as a whole.

Materials And Methods: We combine archaeology, historical sources, biological anthropology, isotopic analyses (δ C, δ N, δ S, Sr/ Sr) and radiocarbon dating, and further analyze bones with different turnover rates (ribs and long bones).

Birthweight, Childhood Body Mass Index, Height and Growth, and Risk of Polycystic Ovary Syndrome.

Introduction: Adult obesity is linked with polycystic ovary syndrome (PCOS), but the importance of body size at ages before PCOS is diagnosed is unknown.

Objective: To investigate associations between a woman's own birthweight, childhood body mass index (BMI), height and growth patterns in relation to her risk of PCOS.

Methods: We included 65,665 girls from the Copenhagen School Health Records Register, born in the period 1960-1996, with information on birthweight and measured weight and height at the ages of 7-13 years.

Risk of gestational diabetes mellitus in nulliparous women - Associations with early life body size and change in body mass index from childhood to adulthood.

Aims: We examined whether a woman's birthweight, childhood height, body mass index (BMI), and BMI changes from childhood to pregnancy were associated with risks of gestational diabetes mellitus (GDM).

Methods: We studied 13,031 women from the Copenhagen School Health Records Register born 1959-1996 with birthweight and measured anthropometric information at ages 7 and/or 13. The diagnosis of GDM (n = 255) was obtained from a national health register.

Associations of childhood BMI and change in BMI from childhood to adulthood with risks of hypertensive disorders in pregnancy.

Background: Maternal overweight (including obesity) is an established risk factor for gestational hypertension and pre-eclampsia. However, it is largely unknown whether body size before adulthood relates to these diseases.

Objectives: We examined whether childhood BMI (in kg/m2) and changes in BMI from childhood to adulthood were associated with gestational hypertension and pre-eclampsia.

Birthweight, childhood overweight, height and growth and adult cancer risks: a review of studies using the Copenhagen School Health Records Register.

Background: Most identified risk factors for cancer primarily occur in adulthood. As cancers generally have long latency periods, it is possible that risk factors acting earlier in life and accumulation of risks across the life course are important. Thus, focusing only on adult overweight as a modifiable risk factor may overlook childhood as an important aetiologic time window when body size is relevant for future cancer risks.

Changes and correlations in height from 7 to 69 years of age across the birth years of 1930 to 1989.

Objectives: The aims of this study were to describe changes in height during childhood and to investigate potential changes in the proportion of children attaining final height in childhood and in correlations between child and adult height across birth cohorts.

Methods: We included 363 059 children (179 906 girls) from the Copenhagen School Health Records Register, who were born between 1930 and 1989, with height measurements at ages 7, 10, or 13 years. Linkages to data resources containing adult height values between ages 18 and 69 years were possible for a subpopulation of 96 133 individuals (23 051 women).

Clonal hematopoiesis in elderly twins: concordance, discordance, and mortality.

Clonal hematopoiesis (CH) of indeterminate potential (CHIP) is defined by mutations in myeloid cancer-associated genes with a variant allele frequency of at least 2%. Recent studies have suggested a possible genetic predisposition to CH. To further explore this phenomenon, we conducted a population-based study of 594 twins from 299 pairs aged 73 to 94 years, all with >20 years' follow-up.

The Danish Twin Registry: An Updated Overview.

The Danish Twin Registry (DTR) was established in the 1950s, when twins born from 1870 to 1910 were ascertained, and has since been extended to include twins from birth cohorts until 2009. The DTR currently comprises of more than 175,000 twins from the 140 birth cohorts. This makes the DTR the oldest nationwide twin register and among the largest in the world.

Breastfeeding duration in infancy and adult risks of type 2 diabetes in a high-income country.

Observed associations between breastfeeding and reduced risk of type 2 diabetes in adulthood may be confounded. We examined if the duration of breastfeeding in infancy was associated with the risk of type 2 diabetes in adulthood after adjustment for a range of prenatal and postnatal risk factors. We prospectively followed 6,044 individuals from the Copenhagen Perinatal Cohort born 1959-1961.

Impact of urbanization on tuberculosis and leprosy prevalence in medieval Denmark.

The consequences of urbanization, such as increased exposure to pathogens, have long been considered detrimental to human health. During the first half of the Danish medieval period, towns were established and throughout the period population increased. The following study analyzes the relationship between urbanization and disease frequency - specifically leprosy and tuberculosis - in four skeletal samples from medieval Denmark using a paleoepidemiological approach.

Inter-laboratory testing of the effect of DNA blocking reagent G2 on DNA extraction from low-biomass clay samples.

Here we show that a commercial blocking reagent (G2) based on modified eukaryotic DNA significantly improved DNA extraction efficiency. We subjected G2 to an inter-laboratory testing, where DNA was extracted from the same clay subsoil using the same batch of kits. The inter-laboratory extraction campaign revealed large variation among the participating laboratories, but the reagent increased the number of PCR-amplified16S rRNA genes recovered from biomass naturally present in the soils by one log unit.

[The implications of using different body mass index references in children and adolescents].

To classify children as overweight or obese, their body mass index (BMI) must be compared with a growth reference and be accompanied by a clinical assessment. In Denmark, there is a lack of consensus on which BMI reference to use; a mix of national and international references are used in clinics, hospitals and research institutions. In this article, the implications of using different references are illustrated with Danish data.