Duration and intensity of lactation and maternal risk of subsequent incident coronary artery disease and stroke-a prospective cohort study.

Background: Although lactation may reduce maternal risk of breast cancer, other potential long-term health benefits of lactation for mothers are largely unknown.

Objectives: We examined whether the durations of predominant and any lactation were associated with maternal risks of coronary artery disease (CAD) and stroke.

Methods: In this prospective cohort study, we followed up 6857 mothers from the Copenhagen Perinatal Cohort who gave birth during 1959-1961 at median age 24 y (IQR, 20-30 y).

Associations between hospitalized infections in the first 24 months of life and risk of cancer in early-mid adulthood.

Background: It is increasingly recognized that early life factors play a role in the rising prevalence of cancer in young adult life. Acute childhood infections may protect against development of cancer, but evidence is limited. We investigated whether infection-related hospital contacts during the first 24 months of life were associated with the risk of cancer in early-mid adult life in a large population-based Danish cohort.

Associations of early life body size and pubertal timing with breast density and postmenopausal breast cancer risk: A mediation analysis.

Purpose: Whether breast density mediates associations between early life body size and pubertal timing with postmenopausal breast cancer is underexplored.

Methods: We studied 33,939 Danish women attending the Capital Mammography Screening Program at ages 50-69 years. Early life anthropometry and pubertal timing information came from the Copenhagen School Health Records Register.

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.

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.

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.

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).

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.

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).

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.

[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.

Ethnic Inequalities in Overweight and Obesity Prevalence among Copenhagen Schoolchildren from 2002 to 2007.

Background: The stabilization in levels of childhood overweight has masked increasing gaps among different ethnic and socioeconomic groups in several countries.

Objective: To examine if levels and trends in childhood overweight and obesity differed by ethnicity and socioeconomic areas in Copenhagen schoolchildren.

Methods: From measured heights and weights of 32,951 children 5-8 and 14-16 years of age, the prevalence of overweight (including obesity) and obesity were estimated using International Obesity Task Force criteria.