Child-to-adult body size change and risk of type 2 diabetes and cardiovascular disease.

AIMS/HYPOTHESIS: Childhood overweight increases the risk of type 2 diabetes and cardiovascular disease in adulthood. However, the impact of childhood leanness on adult obesity and disease risk has been overlooked. We examined the independent and combined influences of child and adult body size on the risk of type 2 diabetes and cardiovascular disease. METHODS: Data from the UK Biobank on 364,695 individuals of European ancestry and free of type 2 diabetes and cardiovascular disease were divided into nine categories based on their self-reported body size at age 10 and measured BMI in adulthood. After a median follow-up of 12.8 years, 33,460 individuals had developed type 2 diabetes and/or cardiovascular disease. We used Cox regression models to assess the associations of body size categories with disease incidence. RESULTS: Individuals with low body size in childhood and high body size in adulthood had the highest risk of type 2 diabetes (HR 4.73; 95% CI 4.50, 4.99), compared to those with average body size in both childhood and adulthood. This was significantly higher than the risk in those with high body size in both childhood and adulthood (HR 4.05; 95% CI 3.84, 4.26). By contrast, cardiovascular disease risk was determined by adult body size, irrespective of childhood body size. CONCLUSIONS/INTERPRETATION: Low body size in childhood exacerbates the risk of type 2 diabetes associated with adult obesity but not the risk of cardiovascular disease. Thus, promoting healthy weight management from childhood to adulthood, among lean children, is crucial.

Integrating multiple lines of evidence to assess the effects of maternal BMI on pregnancy and perinatal outcomes.

BACKGROUND: Higher maternal pre-pregnancy body mass index (BMI) is associated with adverse pregnancy and perinatal outcomes. However, whether these associations are causal remains unclear. METHODS: We explored the relation of maternal pre-/early-pregnancy BMI with 20 pregnancy and perinatal outcomes by integrating evidence from three different approaches (i.e. multivariable regression, Mendelian randomisation, and paternal negative control analyses), including data from over 400,000 women. RESULTS: All three analytical approaches supported associations of higher maternal BMI with lower odds of maternal anaemia, delivering a small-for-gestational-age baby and initiating breastfeeding, but higher odds of hypertensive disorders of pregnancy, gestational hypertension, preeclampsia, gestational diabetes, pre-labour membrane rupture, induction of labour, caesarean section, large-for-gestational age, high birthweight, low Apgar score at 1 min, and neonatal intensive care unit admission. For example, higher maternal BMI was associated with higher risk of gestational hypertension in multivariable regression (OR = 1.67; 95% CI = 1.63, 1.70 per standard unit in BMI) and Mendelian randomisation (OR = 1.59; 95% CI = 1.38, 1.83), which was not seen for paternal BMI (OR = 1.01; 95% CI = 0.98, 1.04). Findings did not support a relation between maternal BMI and perinatal depression. For other outcomes, evidence was inconclusive due to inconsistencies across the applied approaches or substantial imprecision in effect estimates from Mendelian randomisation. CONCLUSIONS: Our findings support a causal role for maternal pre-/early-pregnancy BMI on 14 out of 20 adverse pregnancy and perinatal outcomes. Pre-conception interventions to support women maintaining a healthy BMI may reduce the burden of obstetric and neonatal complications. FUNDING: Medical Research Council, British Heart Foundation, European Research Council, National Institutes of Health, National Institute for Health Research, Research Council of Norway, Wellcome Trust.

Body weight in childhood, adolescence, and young adulthood in relation to later risk of disabilities and early retirement among Danish female nurses.

BACKGROUND: Obesity is now the most common health problem in the younger population in Western societies and obesity rates are higher in lower socioeconomic status (SES) groups. We investigated whether overweight in childhood, independently of overweight in adulthood, influenced adult employment status and later risk of having disabilities. Using data from the Danish Female Nurse Cohort study, we examined associations between overweight in childhood/adolescence, and young adulthood and disabilities and early retirement in later adulthood (>44 years) and whether it was influenced by menopausal age (

Childhood adversity trajectories and weight status in young adult men: a register-based study including 359,783 Danish men.

BACKGROUND: Childhood adversity has previously been associated with overweight and obesity in adult life, but there is a need for larger population-based studies using prospectively obtained adversity trajectories across childhood to confirm these associations. Moreover, childhood adversity may also be associated with underweight, which is less often studied. The aim of the current study is to investigate the association between childhood adversity trajectories from 0-15 years with weight categories in young adult men. METHODS: The Danish Life Course Cohort (DANLIFE) was linked with the Danish Conscription Registry resulting in a study sample of 359,783 men, who have been assigned to one of five previously identified adversity trajectories from 0-15 years: "low adversity", "early material deprivation", "persistent material deprivation", "loss or threat of loss", and "high adversity". Height and weight in young adulthood was assessed at a draft board examination at age 18-26 years. Associations of adversity trajectories and weight categories were investigated in multinomial regression models. RESULTS: Compared with the "low adversity" group, the four other adversity groups had higher risks of underweight, overweight, and obesity. The "high adversity" group showed the strongest associations with both underweight (1.44 (1.32, 1.58)) and obesity (1.50 (1.39, 1.61)) when adjusted for parental origin, birth year, age at draft board examination, and maternal age. CONCLUSION: Childhood adversity, experienced between 0 and 15 years of life, was associated with a higher risk of underweight, overweight, and obesity in young adulthood among men.

Maternal obesity, interpregnancy weight changes and congenital heart defects in the offspring: a nationwide cohort study.

OBJECTIVE: To evaluate the association between maternal BMI and congenital heart defects (CHDs) in the offspring when including live births, stillbirths, aborted and terminated pregnancies and to investigate if maternal interpregnancy weight changes between the first and second pregnancy influences the risk of foetal CHDs. METHODS: A nationwide cohort study of all singleton pregnancies in Denmark from 2008 to 2018. Data were retrieved from the Danish Foetal Medicine Database, which included both pre- and postnatal diagnoses of CHDs. Children or foetuses with chromosomal aberrations were excluded. Odds ratios were calculated with logistic regression models for CHDs overall, severe CHDs and five of the most prevalent subtypes of CHDs. RESULTS: Of the 547 105 pregnancies included in the cohort, 5 442 had CHDs (1.0%). Risk of CHDs became gradually higher with higher maternal BMI; for BMI 25-29.9 kg/m2, adjusted odds ratio (aOR) 1.17 (95% CI 1.10-1.26), for BMI 30-34.9 kg/m2, aOR 1.21 (95% CI 1.09-1.33), for BMI 35-39.9 kg/m2, aOR 1.29 (95% CI 1.11-1.50) and for BMI ≥ 40 kg/m2, aOR 1.85 (95% CI 1.54-2.21). Data was adjusted for maternal age, smoking status and year of estimated due date. The same pattern was seen for the subgroup of severe CHDs. Among the atrioventricular septal defects (n = 231), an association with maternal BMI ≥ 30 kg/m2 was seen, OR 1.67 (95% CI 1.13-2.44). 109 654 women were identified with their first and second pregnancies in the cohort. Interpregnancy BMI change was associated with the risk of CHDs in the second pregnancy (BMI 2 to < 4 kg/m2: aOR 1.29, 95% CI 1.09-1.53; BMI ≥ 4 kg/m2: aOR 1.36, 95% CI 1.08-1.68). CONCLUSION: The risk of foetal CHDs became gradually higher with higher maternal BMI and interpregnancy weight increases above 2 BMI units were also associated with a higher risk of CHDs.

Change in abdominal obesity after colon cancer surgery - effects of left-sided and right-sided colonic resection.

BACKGROUND: Excess abdominal visceral adipose tissue (VAT) is associated with metabolic diseases and poor survival in colon cancer (CC). We assessed the impact of different types of CC surgery on changes in abdominal fat depots. MATERIAL AND METHODS: Computed tomography (CT)-scans performed preoperative and 3 years after CC surgery were analyzed at L3-level for VAT, subcutaneous adipose tissue (SAT) and total adipose tissue (TAT) areas. We assessed changes in VAT, SAT, TAT and VAT/SAT ratio after 3 years and compared the changes between patients who had undergone left-sided and right-sided colonic resection in the total population and in men and women separately. RESULTS: A total of 134 patients with stage I-III CC undergoing cancer surgery were included. Patients who had undergone left-sided colonic resection had after 3 years follow-up a 5% (95% CI: 2-9%, p < 0.01) increase in abdominal VAT, a 4% (95% CI: 2-6%, p < 0.001) increase in SAT and a 5% increase (95% CI: 2-7%, p < 0.01) in TAT. Patients who had undergone right-sided colonic resection had no change in VAT, but a 6% (95% CI: 4-9%, p < 0.001) increase in SAT and a 4% (95% CI: 1-7%, p < 0.01) increase in TAT after 3 years. Stratified by sex, only males undergoing left-sided colonic resection had a significant VAT increase of 6% (95% CI: 2-10%, p < 0.01) after 3 years. CONCLUSION: After 3 years follow-up survivors of CC accumulated abdominal adipose tissue. Notably, those who underwent left-sided colonic resection had increased VAT and SAT, whereas those who underwent right-sided colonic resection demonstrated solely increased SAT.

Changes in weight status during the COVID-19 pandemic: impact of educational level and mental health.

BACKGROUND: The COVID-19 pandemic has resulted in a disruption of daily routines and changes in health behaviors leading to widespread concerns about unfavorable changes in weight status and a potential increase in the prevalence of obesity. This study examined the long-term impact of the COVID-19 pandemic on changes in weight status and its possible dependency on educational level and mental health. METHODS: The study utilizes the Danish Health and Well-being Survey with repeated self-reported information on weight status collected before the COVID-19 pandemic (autumn of 2019) and twice during the pandemic (autumns of 2020 and 2021). Information on educational level was derived from registers, whereas mental health was measured using validated scales. Generalized estimating equations were performed to investigate changes in mean weight and body mass index (BMI) category (BMI < 30 to BMI ≥ 30) between 2019 and 2021 and to investigate potential differences in changes in weight status by pre-pandemic educational level and mental health. RESULTS: Mean weight significantly increased by 0.34 kg [95% confidence interval (CI): 0.16-0.51] in 2020 and by 0.46 kg (95% CI: 0.26-0.66) in 2021 compared with pre-pandemic weight status. The increase was greater among individuals with lower educational levels and poorer mental health. There were no significant changes in BMI category during the pandemic. CONCLUSION: The results showed a significant increase in mean weight among the Danish population, particularly among individuals with lower educational levels and poorer mental health, but without detectable differences in obesity, supporting a long-term but minor impact of the COVID-19 pandemic on weight status.

Gestational age at birth and body size from infancy through adolescence: An individual participant data meta-analysis on 253,810 singletons in 16 birth cohort studies.

BACKGROUND: Preterm birth is the leading cause of perinatal morbidity and mortality and is associated with adverse developmental and long-term health outcomes, including several cardiometabolic risk factors and outcomes. However, evidence about the association of preterm birth with later body size derives mainly from studies using birth weight as a proxy of prematurity rather than an actual length of gestation. We investigated the association of gestational age (GA) at birth with body size from infancy through adolescence. METHODS AND FINDINGS: We conducted a two-stage individual participant data (IPD) meta-analysis using data from 253,810 mother-child dyads from 16 general population-based cohort studies in Europe (Denmark, Finland, France, Italy, Norway, Portugal, Spain, the Netherlands, United Kingdom), North America (Canada), and Australasia (Australia) to estimate the association of GA with body mass index (BMI) and overweight (including obesity) adjusted for the following maternal characteristics as potential confounders: education, height, prepregnancy BMI, ethnic background, parity, smoking during pregnancy, age at child's birth, gestational diabetes and hypertension, and preeclampsia. Pregnancy and birth cohort studies from the LifeCycle and the EUCAN-Connect projects were invited and were eligible for inclusion if they had information on GA and minimum one measurement of BMI between infancy and adolescence. Using a federated analytical tool (DataSHIELD), we fitted linear and logistic regression models in each cohort separately with a complete-case approach and combined the regression estimates and standard errors through random-effects study-level meta-analysis providing an overall effect estimate at early infancy (>0.0 to 0.5 years), late infancy (>0.5 to 2.0 years), early childhood (>2.0 to 5.0 years), mid-childhood (>5.0 to 9.0 years), late childhood (>9.0 to 14.0 years), and adolescence (>14.0 to 19.0 years). GA was positively associated with BMI in the first decade of life, with the greatest increase in mean BMI z-score during early infancy (0.02, 95% confidence interval (CI): 0.00; 0.05, p < 0.05) per week of increase in GA, while in adolescence, preterm individuals reached similar levels of BMI (0.00, 95% CI: -0.01; 0.01, p 0.9) as term counterparts. The association between GA and overweight revealed a similar pattern of association with an increase in odds ratio (OR) of overweight from late infancy through mid-childhood (OR 1.01 to 1.02) per week increase in GA. By adolescence, however, GA was slightly negatively associated with the risk of overweight (OR 0.98 [95% CI: 0.97; 1.00], p 0.1) per week of increase in GA. Although based on only four cohorts (n = 32,089) that reached the age of adolescence, data suggest that individuals born very preterm may be at increased odds of overweight (OR 1.46 [95% CI: 1.03; 2.08], p < 0.05) compared with term counterparts. Findings were consistent across cohorts and sensitivity analyses despite considerable heterogeneity in cohort characteristics. However, residual confounding may be a limitation in this study, while findings may be less generalisable to settings in low- and middle-income countries. CONCLUSIONS: This study based on data from infancy through adolescence from 16 cohort studies found that GA may be important for body size in infancy, but the strength of association attenuates consistently with age. By adolescence, preterm individuals have on average a similar mean BMI to peers born at term.

Correction: Gestational age at birth and body size from infancy through adolescence: An individual participant data meta-analysis on 253,810 singletons in 16 birth cohort studies.

[This corrects the article DOI: 10.1371/journal.pmed.1004036.].

Birth weight, childhood body mass index, and risk of diverticular disease in adulthood.

OBJECTIVE: Adult overweight is associated with increased risk of diverticular disease (DD). We investigated associations between birthweight and childhood body mass index (BMI) and DD. METHODS: Cohort study of 346,586 persons born during 1930-1996 with records in the Copenhagen School Health Records Register. Data included birthweight, and height and weight from ages 7 through 13. We used Cox proportional hazard regression to examine associations between birthweight and BMI z-scores and DD registered in the Danish National Patient Registry. Due to non-proportionality, we followed participants from age 18-49 and from age 50. RESULTS: During follow-up, 5459 (3.2%) women and 4429 (2.5%) men had DD. For low and high BMI in childhood, we observed a higher risk of DD before age 50. Among women with z-scores <0 at age 13, the hazard ratio (HR) was 1.16 [95% confidence interval (CI): 0.98-1.39] per one-point lower z-score. For z-scores ≥0 at age 13, the HR was 1.30 (95% CI: 1.11-1.51) per one-point higher z-score. Among men with z-scores <0 at age 13, the HR was 1.02 (95% CI: 0.85-1.22). For z-scores ≥0 at age 13, the HR was 1.54 (95% CI: 1.34-1.78). Z-scores ≥0 were not associated with DD after age 50. Among women only, birthweight was inversely associated with DD before age 50 [HR = 0.90 (95% CI: 0.83-0.99) per 500 g higher birthweight]. CONCLUSION: BMI z-scores below and above zero in childhood were associated with higher risk of DD before age 50. In addition, we observed lower risk of DD among women, the higher their birthweight.

Early childhood adversity and body mass index in childhood and adolescence: linking registry data on adversities with school health records of 53,401 children from Copenhagen.

OBJECTIVE: We examined whether childhood adversity experienced in early childhood (0-5 years) is related to body mass index (BMI) in childhood (6-7 years) and adolescence (12-15 years). METHODS: This study combined data from the nationwide register-based DANLIFE study on childhood adversities with data on height and weight of school children in Copenhagen. Data were available for 53,401 children born in Denmark between 1980 and 1996. Children were divided into groups of early childhood adversity by applying group-based multi-trajectory modelling using their yearly count of childhood adversity in three dimensions (i.e., material deprivation, loss or threat of loss, and family dynamics) from 0-5 years. Direct and total associations between the early childhood adversity groups and BMI z-scores in childhood and adolescence were estimated using sex-stratified structural equation models. RESULTS: Five exclusive and exhaustive groups of early childhood adversity were identified, which were characterized by low adversity (51%), moderate material deprivation (30%), high material deprivation (14%), loss or threat of loss (3%) and high adversity (2%). Boys and girls exposed to moderate or high material deprivation and loss or threat of loss had a slightly higher BMI z-score, especially in adolescence, compared with those in the low adversity group, with the strongest association found for girls in the loss or threat of loss group (b (95% CI) = 0.18 (0.10, 0.26)). Additionally, boys in the high adversity group had a slightly lower BMI z-score in childhood than boys in the low adversity group (b (95% CI) = -0.12 (-0.22, -0.02)). CONCLUSIONS: Whereas associations with BMI were found for children and adolescents exposed to material deprivation, loss or threat of loss, and high adversity, the effect sizes were generally small. Contrary to prevailing hypotheses, weight changes in childhood is probably not a major explanatory mechanism linking early childhood adversity with later-life morbidity.

Sequencing and de novo assembly of 150 genomes from Denmark as a population reference.

Hundreds of thousands of human genomes are now being sequenced to characterize genetic variation and use this information to augment association mapping studies of complex disorders and other phenotypic traits. Genetic variation is identified mainly by mapping short reads to the reference genome or by performing local assembly. However, these approaches are biased against discovery of structural variants and variation in the more complex parts of the genome. Hence, large-scale de novo assembly is needed. Here we show that it is possible to construct excellent de novo assemblies from high-coverage sequencing with mate-pair libraries extending up to 20 kilobases. We report de novo assemblies of 150 individuals (50 trios) from the GenomeDenmark project. The quality of these assemblies is similar to those obtained using the more expensive long-read technology. We use the assemblies to identify a rich set of structural variants including many novel insertions and demonstrate how this variant catalogue enables further deciphering of known association mapping signals. We leverage the assemblies to provide 100 completely resolved major histocompatibility complex haplotypes and to resolve major parts of the Y chromosome. Our study provides a regional reference genome that we expect will improve the power of future association mapping studies and hence pave the way for precision medicine initiatives, which now are being launched in many countries including Denmark.

Changes in adult obesity prevalence in Denmark, 1987-2021: age-period-cohort analysis of nationally representative data.

BACKGROUND: During the last decades, the prevalence of obesity [body mass index (BMI): weight/height2), ≥30.00 kg/m2] among adults has increased considerably. We examined whether this increase in a high-income, welfare state, like Denmark was driven by age, period or cohort effects, which would inform preventive strategies aiming at reducing the prevalence. METHODS: We used data from the National Representative Health and Morbidity Studies, which are representative surveys of the Danish adult population (age 16 years and above), conducted in 1987, 1994, 2000, 2005, 2010, 2013, 2017 and 2021 (N = 91 684). Participants reported height and weight, from which BMI was calculated after correction for systematic bias in self-reported data and non-response. Age, survey year and birth cohorts were mutually adjusted and adjusted for sex in generalized linear models. RESULTS: The obesity prevalence increased from 6.1% in 1987 to 18.4% in 2021, similarly in men (18.8%) and women (18.0%) and in all age groups. Age had an inverted u-shaped effect on the prevalence. Compared with individuals aged 16-24 years, the highest rate of obesity was seen for the age group 55-64 years [rate ratio 3.27, 95% confidence interval (CI): 2.58; 4.14]. The increasing rate for each recent survey year over time was compatible with a period effect without any birth cohort effects. The rate for obesity in 2021 was 4.16 in 1987 vs. 1987 (95% CI: 3.10; 5.59). CONCLUSIONS: Obesity prevalence in Denmark increased steadily during the period 1987 through 2021, primarily driven by secular changes over time across all ages and birth cohorts.

Do gene-environment interactions have implications for the precision prevention of type 2 diabetes?

The past decades have seen a rapid global rise in the incidence of type 2 diabetes. This surge has been driven by diabetogenic environmental changes that may act together with a genetic predisposition to type 2 diabetes. It is possible that there is a synergistic gene-environment interaction, where the effects of the diabetogenic environment depend on the genetic predisposition to type 2 diabetes. Randomised trials have shown that it is possible to delay, or even prevent the development of type 2 diabetes in individuals at elevated risk through behavioural modification, focusing on weight loss, physical activity and diet. There is wide heterogeneity between individuals regarding the effectiveness of these interventions, which could, in part, be due to genetic differences. However, the studies of gene-environment interactions performed thus far suggest that behavioural modifications appear equally effective in reducing the incidence of type 2 diabetes from the stage of impaired glucose tolerance, regardless of the known underlying genetic predisposition. Recent studies suggest that there may be several subtypes of type 2 diabetes, which give new opportunities for gaining insight into gene-environment interactions. At present, the role of gene-environment interactions in the development of type 2 diabetes remains unclear. With many puzzle pieces missing in the general picture of type 2 diabetes development, the available evidence of gene-environment interactions is not ready for translation to individualised type 2 diabetes prevention based on genetic profiling.

Lipolysis defect in people with obesity who undergo metabolic surgery.

OBJECTIVE: Cross-sectional studies demonstrate that catecholamine stimulation of fat cell lipolysis is blunted in obesity. We investigated whether this defect persists after substantial weight loss has been induced by metabolic surgery, and whether it is related to the outcome. DESIGN/METHODS: Patients with obesity not able to successfully reduce body weight by conventional means (n = 126) were investigated before and 5 years after Roux-en-Y gastric bypass surgery (RYGB). They were compared with propensity-score matched subjects selected from a control group (n = 1017), and with the entire group after adjustment for age, sex, body mass index (BMI), fat cell volume and other clinical parameters. Catecholamine-stimulated lipolysis (glycerol release) was investigated in isolated fat cells using noradrenaline (natural hormone) or isoprenaline (synthetic beta-adrenoceptor agonist). RESULTS: Following RYGB, BMI was reduced from 39.9 (37.5-43.5) (median and interquartile range) to 29.5 (26.7-31.9) kg/m2 (p < 0.0001). The post-RYGB patients had about 50% lower lipolysis rates compared with the matched and total series of controls (p < 0.0005). Nordrenaline activation of lipolysis at baseline was associated with the RYGB effect; those with high lipolysis activation (upper tertile) lost 30%-45% more in body weight, BMI or fat mass than those with low (bottom tertile) initial lipolysis activation (p < 0.0007). CONCLUSION: Patients with obesity requiring metabolic surgery have impaired ability of catecholamines to stimulate lipolysis, which remains despite long-term normalization of body weight by RYGB. Furthermore, preoperative variations in the ability of catecholamines to activate lipolysis may predict the long-term reduction in body weight and fat mass.

Maternal anxiety during pregnancy and newborn epigenome-wide DNA methylation.

Maternal anxiety during pregnancy is associated with adverse foetal, neonatal, and child outcomes, but biological mechanisms remain unclear. Altered foetal DNA methylation (DNAm) has been proposed as a potential underlying mechanism. In the current study, we performed a meta-analysis to examine the associations between maternal anxiety, measured prospectively during pregnancy, and genome-wide DNAm from umbilical cord blood. Sixteen non-overlapping cohorts from 12 independent longitudinal studies of the Pregnancy And Childhood Epigenetics Consortium participated, resulting in a combined dataset of 7243 mother-child dyads. We examined prenatal anxiety in relation to genome-wide DNAm and differentially methylated regions. We observed no association between the general symptoms of anxiety during pregnancy or pregnancy-related anxiety, and DNAm at any of the CpG sites, after multiple-testing correction. Furthermore, we identify no differentially methylated regions associated with maternal anxiety. At the cohort-level, of the 21 associations observed in individual cohorts, none replicated consistently in the other cohorts. In conclusion, contrary to some previous studies proposing cord blood DNAm as a promising potential mechanism explaining the link between maternal anxiety during pregnancy and adverse outcomes in offspring, we found no consistent evidence for any robust associations between maternal anxiety and DNAm in cord blood. Larger studies and analysis of DNAm in other tissues may be needed to establish subtle or subgroup-specific associations between maternal anxiety and the foetal epigenome.

Epidemiology of Obesity.

Obesity is in theory defined on the basis of the excess health risk caused by adiposity exceeding the size normally found in the population, but for practical reasons, the World Health Organization (WHO) has defined obesity as a body mass index (weight (kg)/height (m)2) of 30 or above for adults. WHO considers the steep increases in prevalence of obesity in all age groups, especially since the 1970s as a global obesity epidemic. Today, approximately 650 million adult people and approximately 340 million children and adolescence (5-19 years) suffer from obesity. It is generally more prevalent among women and older age groups than among men and younger age groups. Beyond the necessity of availability of food, evidence about causes of obesity is still very limited. However, studies have shown that obesity 'runs in families', where both genetics and environmental, and especially social, factors play important roles. Obesity is associated with an increased risk of many adverse medical, mental and social consequences, including a strong relation to type 2 diabetes. Type 2 diabetes and related metabolic syndrome and diseases are major contributors to the excess morbidity and mortality associated with obesity.

Maternal weight change from prepregnancy to 18 months postpartum and subsequent risk of hypertension and cardiovascular disease in Danish women: A cohort study.

BACKGROUND: One-fourth of women experience substantially higher weight years after childbirth. We examined weight change from prepregnancy to 18 months postpartum according to subsequent maternal risk of hypertension and cardiovascular disease (CVD). METHODS AND FINDINGS: We conducted a cohort study of 47,966 women with a live-born singleton within the Danish National Birth Cohort (DNBC; 1997-2002). Interviews during pregnancy and 6 and 18 months postpartum provided information on height, gestational weight gain (GWG), postpartum weights, and maternal characteristics. Information on pregnancy complications, incident hypertension, and CVD was obtained from the National Patient Register. Using Cox regression, we estimated adjusted hazard ratios (HRs; 95% confidence interval [CI]) for hypertension and CVD through 16 years of follow-up. During this period, 2,011 women were diagnosed at the hospital with hypertension and 1,321 with CVD. The women were on average 32.3 years old (range 18.0-49.2) at start of follow-up, 73% had a prepregnancy BMI <25, and 27% a prepregnancy BMI ≥25. Compared with a stable weight (±1 BMI unit), weight gains from prepregnancy to 18 months postpartum of >1-2 and >2 BMI units were associated with 25% (10%-42%), P = 0.001 and 31% (14%-52%), P < 0.001 higher risks of hypertension, respectively. These risks were similar whether weight gain presented postpartum weight retention or a new gain from 6 months to 18 months postpartum and whether GWG was below, within, or above the recommendations. For CVD, findings differed according to prepregnancy BMI. In women with normal-/underweight, weight gain >2 BMI units and weight loss >1 BMI unit were associated with 48% (17%-87%), P = 0.001 and 28% (6%-55%), P = 0.01 higher risks of CVD, respectively. Further, weight loss >1 BMI unit combined with a GWG below recommended was associated with a 70% (24%-135%), P = 0.001 higher risk of CVD. No such increased risks were observed among women with overweight/obesity (interaction by prepregnancy BMI, P = 0.01, 0.03, and 0.03, respectively). The limitations of this observational study include potential confounding by prepregnancy metabolic health and self-reported maternal weights, which may lead to some misclassification. CONCLUSIONS: Postpartum weight retention/new gain in all mothers and postpartum weight loss in mothers with normal-/underweight may be associated with later adverse cardiovascular health.

Change in Overweight from Childhood to Early Adulthood and Risk of Type 2 Diabetes.

BACKGROUND: Childhood overweight is associated with an increased risk of type 2 diabetes in adulthood. We investigated whether remission of overweight before early adulthood reduces this risk. METHODS: We conducted a study involving 62,565 Danish men whose weights and heights had been measured at 7 and 13 years of age and in early adulthood (17 to 26 years of age). Overweight was defined in accordance with Centers for Disease Control and Prevention criteria. Data on type 2 diabetes status (at age ≥30 years, 6710 persons) were obtained from a national health registry. RESULTS: Overweight at 7 years of age (3373 of 62,565 men; 5.4%), 13 years of age (3418 of 62,565; 5.5%), or early adulthood (5108 of 62,565; 8.2%) was positively associated with the risk of type 2 diabetes; associations were stronger at older ages at overweight and at younger ages at diagnosis of type 2 diabetes. Men who had had remission of overweight before the age of 13 years had a risk of having type 2 diabetes diagnosed at 30 to 60 years of age that was similar to that among men who had never been overweight (hazard ratio, 0.96; 95% confidence interval [CI], 0.75 to 1.21). As compared with men who had never been overweight, men who had been overweight at 7 and 13 years of age but not during early adulthood had a higher risk of type 2 diabetes (hazard ratio, 1.47; 95% CI, 1.10 to 1.98), but their risk was lower than that among men with persistent overweight (hazard ratio [persistently overweight vs. never overweight], 4.14; 95% CI, 3.57 to 4.79). An increase in body-mass index between 7 years of age and early adulthood was associated with an increased risk of type 2 diabetes, even among men whose weight had been normal at 7 years of age. CONCLUSIONS: Childhood overweight at 7 years of age was associated with increased risks of adult type 2 diabetes only if it continued until puberty or later ages. (Funded by the European Union.).

Two genetic analyses to elucidate causality between body mass index and personality.

BACKGROUND/OBJECTIVES: Many personality traits correlate with BMI, but the existence and direction of causal links between them are unclear. If personality influences BMI, knowing this causal direction could inform weight management strategies. Knowing that BMI instead influences personality would contribute to a better understanding of the mechanisms of personality development and the possible psychological effects of weight change. We tested the existence and direction of causal links between BMI and personality. SUBJECTS/METHODS: We employed two genetically informed methods. In Mendelian randomization, allele scores were calculated to summarize genetic propensity for the personality traits neuroticism, worry, and depressive affect and used to predict BMI in an independent sample (N = 3 541). Similarly, an allele score for BMI was used to predict eating-specific and domain-general phenotypic personality scores (PPSs; aggregate scores of personality traits weighted by BMI). In a direction of causation (DoC) analysis, twin data from five countries (N = 5424) were used to assess the fit of four alternative models: PPSs influencing BMI, BMI influencing PPSs, reciprocal causation, and no causation. RESULTS: In Mendelian randomization, the allele score for BMI predicted domain-general (ß = 0.05; 95% CI: 0.02, 0.08; P = 0.003) and eating-specific PPS (ß = 0.06; 95% CI: 0.03, 0.09; P < 0.001). The allele score for worry also predicted BMI (ß = -0.05; 95% CI: -0.08, -0.02; P < 0.001), while those for neuroticism and depressive affect did not (P ≥ 0.459). In DoC, BMI similarly predicted domain-general (ß = 0.21; 95% CI:, 0.18, 0.24; P < 0.001) and eating-specific personality traits (ß = 0.19; 95% CI:, 0.16, 0.22; P < 0.001), suggesting causality from BMI to personality traits. In exploratory analyses, links between BMI and domain-general personality traits appeared reciprocal for higher-weight individuals (BMI > ~25). CONCLUSIONS: Although both genetic analyses suggested an influence of BMI on personality traits, it is not yet known if weight management interventions could influence personality. Personality traits may influence BMI in turn, but effects in this direction appeared weaker.