Prenatal exposures and glucose metabolism in adulthood: are effects mediated through birth weight and adiposity?

Maternal hypertensive disorders during pregnancy and the risk of offspring diabetes mellitus in childhood, adolescence, and early adulthood: a nationwide population-based cohort study

BACKGROUND

Maternal hypertensive disorders during pregnancy (HDP) have been suggested to contribute to the development of offspring cardiovascular disease later in life, but empirical evidence remains inconsistent. This study was aimed to assess the association of maternal overall and type-specific HDPs with diabetes in offspring from childhood to early adulthood.

METHODS

Using Danish national health registers, a total of 2,448,753 individuals born in Denmark from 1978 to 2018 were included in this study. Maternal HDP included chronic hypertension, gestational hypertension, and preeclampsia. The outcome of interest was diabetes in offspring (including type 1, type 2, and gestational diabetes). The follow-up of offspring started at birth and ended at the first diagnosis of diabetes, emigration from Denmark, death, or time end on 31 December 2018, whichever came first. Cox proportional hazards regression was used to evaluate the hazard ratios (HRs) with 95% confidence intervals (CIs) of the association between maternal HDP and diabetes (including type 1, type 2, and gestational diabetes) in offspring from birth to young adulthood (up to 41 years), with the offspring's age as the time scale.

RESULTS

During a follow-up of up to 41 (median: 19.3) years, 1247 offspring born to mothers with HDP and 23,645 offspring born to mothers without HDP were diagnosed with diabetes. Compared with offspring born to mothers without HDP, those born to mothers with HDP had an increased risk for overall diabetes (HR=1.27, 95% CI=1.20-1.34), as well as for type 2 diabetes (HR=1.57, 95% CI=1.38-1.78) and gestational diabetes (HR=1.37, 95% CI=1.25-1.49). We did not observe obvious increased risk for type 1 diabetes (HR=1.08, 95% CI=0.98-1.18). Offspring of mothers with gestational hypertension (HR=1.37, 95% CI=1.00-1.88) or preeclampsia (HR=1.62, 95% CI=1.41-1.87) had higher risks of type 2 diabetes. The strongest association was observed for severe preeclampsia, with a 2-fold risk of type 2 diabetes (HR=2.00, 95% CI=1.42-2.82). The association between maternal HDP and type 1 diabetes did not reach statistical significance, except for maternal gestational hypertension (HR=1.41, 95%CI=1.17-1.71). In addition, we found that offspring born to mothers with any subtypes of maternal HDP had higher risk of gestational diabetes, and the corresponding HRs (95%CIs) for chronic hypertension, gestational hypertension, and preeclampsia were 1.60 (1.06-2.41), 1.29 (1.04-1.59), and 1.38 (1.24-1.53), respectively. We also observed stronger associations among offspring of mothers with HDP and comorbid diabetes (HR=4.64, 95%CI=3.85-5.60) than offspring of mothers with HDP or diabetes alone.

CONCLUSIONS

Offspring of mothers with HDP, especially mothers with comorbid diabetes, had an increased risk of diabetes later in their life. Our findings suggest that timely and effective prevention of HDP in women of childbearing age should be taken into consideration as diabetes prevention and control strategies for their generations.

Exposure to persistent organic pollutants alters the serum metabolome in non-obese diabetic mice

INTRODUCTION

Autoimmune disorders such as type 1 diabetes (T1D) are believed to be caused by the interplay between several genetic and environmental factors. Elucidation of the role of environmental factors in metabolic and immune dysfunction leading to autoimmune disease is not yet well characterized.

OBJECTIVES

Here we investigated the impact of exposure to a mixture of persistent organic pollutants (POPs) on the metabolome in non-obese diabetic (NOD) mice, an experimental model of T1D. The mixture contained organochlorides, organobromides, and per- and polyfluoroalkyl substances (PFAS).

METHODS

Analysis of molecular lipids (lipidomics) and bile acids in serum samples was performed by UPLC-Q-TOF/MS, while polar metabolites were analyzed by GC-Q-TOF/MS.

RESULTS

Experimental exposure to the POP mixture in these mice led to several metabolic changes, which were similar to those previously reported as associated with PFAS exposure, as well as risk of T1D in human studies. This included an increase in the levels of sugar derivatives, triacylglycerols and lithocholic acid, and a decrease in long chain fatty acids and several lipid classes, including phosphatidylcholines, lysophosphatidylcholines and sphingomyelins.

CONCLUSION

Taken together, our study demonstrates that exposure to POPs results in an altered metabolic signature previously associated with autoimmunity.

Maternal hypertensive disorders in pregnancy and early childhood cardiometabolic risk factors: The Generation R Study

The objective of this study was to determine the associations between hypertensive disorders of pregnancy and early childhood cardiometabolic risk factors in the offspring. Therefore, 7794 women from the Generation Rotterdam Study were included, an ongoing population-based prospective birth cohort. Women with a hypertensive disorder of pregnancy were classified as such when they were affected by pregnancy induced hypertension, pre-eclampsia or the haemolysis, elevated liver enzymes and low platelet count (HELLP) syndrome during pregnancy. Early childhood cardiometabolic risk factors were defined as the body mass index at the age of 2, 6, 12, 36 months and 6 years. Additionally, it included systolic blood pressure, diastolic blood pressure, total fat mass, cholesterol, triglycerides, insulin and clustering of cardiometabolic risk factors at 6 years of age. Sex-specific differences in the associations between hypertensive disorders and early childhood cardiometabolic risk factors were investigated. Maternal hypertensive disorders of pregnancy were inversely associated with childhood body mass index at 12 months (confounder model: -0.15 SD, 95% CI -0.27; -0.03) and childhood triglyceride at 6 years of age (confounder model: -0.28 SD, 95% CI -0.45; -0.10). For the association with triglycerides, this was only present in girls. Maternal hypertensive disorders of pregnancy were not associated with childhood body mass index at 2, 6 and 36 months. No associations were observed between maternal hypertensive disorders of pregnancy and systolic blood pressure, diastolic blood pressure, body mass index, fat mass index and cholesterol levels at 6 years of age. Our findings do not support an independent and consistent association between maternal hypertensive disorders of pregnancy and early childhood cardiometabolic risk factors in their offspring. However, this does not rule out possible longer term effects of maternal hypertensive disorders of pregnancy on offspring cardiometabolic health.

Decreased Lymphangiogenic Activities and Genes Expression of Cord Blood Lymphatic Endothelial Progenitor Cells (VEGFR3+/Pod+/CD11b+ Cells) in Patient with Preeclampsia

The abnormal development or disruption of the lymphatic vasculature has been implicated in metabolic and hypertensive diseases. Recent evidence suggests that the offspring exposed to preeclampsia (PE) in utero are at higher risk of long-term health problems, such as cardiovascular and metabolic diseases in adulthood, owing to in utero fetal programming. We aimed to investigate lymphangiogenic activities in the lymphatic endothelial progenitor cells (LEPCs) of the offspring of PE. Human umbilical cord blood LEPCs from pregnant women with severe PE (n = 10) and gestationally matched normal pregnancies (n = 10) were purified with anti-vascular endothelial growth factor receptor 3 (VEGFR3)/podoplanin/CD11b microbeads using a magnetic cell sorter device. LEPCs from PE displayed significantly delayed differentiation and reduced formation of lymphatic endothelial cell (LEC) colonies compared with the LEPCs from normal pregnancies. LECs differentiated from PE-derived LEPCs exhibited decreased tube formation, migration, proliferation, adhesion, wound healing, and 3D-sprouting activities as well as increased lymphatic permeability through the disorganization of VE-cadherin junctions, compared with the normal pregnancy-derived LECs. In vivo, LEPCs from PE showed significantly reduced lymphatic vessel formation compared to the LEPCs of the normal pregnancy. Gene expression analysis revealed that compared to the normal pregnancy-derived LECs, the PE-derived LECs showed a significant decrease in the expression of pro-lymphangiogenic genes (GREM1, EPHB3, VEGFA, AMOT, THSD7A, ANGPTL4, SEMA5A, FGF2, and GBX2). Collectively, our findings demonstrate, for the first time, that LEPCs from PE have reduced lymphangiogenic activities in vitro and in vivo and show the decreased expression of pro-lymphangiogenic genes. This study opens a new avenue for investigation of the molecular mechanism of LEPC differentiation and lymphangiogenesis in the offspring of PE and subsequently may impact the treatment of long-term health problems such as cardiovascular and metabolic disorders of offspring with abnormal development of lymphatic vasculature.

Replacing smoking with vaping during pregnancy: Impacts on metabolic health in mice

Smoking is a significant risk factor for the development of metabolic diseases. Due to social pressures to quit smoking, many pregnant women are vaping as an alternative nicotine source. However, the metabolic consequences of replacing tobacco cigarettes with e-cigarettes during pregnancy are unknown. Therefore, in the mothers and their offspring, we investigated the metabolic and hepatic impacts of replacing cigarette smoke with e-vapour during pregnancy. Female BALB/c mice were either air-exposed or cigarette smoke-exposed (SE) from six weeks before pregnancy until lactation. At mating, a subset of the SE mice were instead exposed to e-vapour. Markers of glucose and lipid metabolism were measured in the livers and plasma, from the mothers and their male offspring (13 weeks). In the SE mothers, plasma insulin levels were reduced, leading to downstream increases in hepatic gluconeogenesis and plasma non-esterified fatty acids (NEFA). In the e-vapour replacement mothers, these changes were not as significant. In the SE offspring, there was impaired glucose tolerance, and increased plasma NEFA and liver triglyceride concentrations. E-vapour replacement restored lipid homeostasis but did not improve glucose tolerance. Therefore, in a murine model, low dose e-cigarette replacement during pregnancy is less toxic than cigarette smoke.

Impact of parental smoking on adipokine profiles and cardiometabolic risk factors in Chinese children

BACKGROUND AND AIMS

The mechanisms by which passive smoking leads to cardiometabolic risks, and the tissues involved still require elucidation. We aimed to evaluate the association of parental smoking exposure (PSE) with the secretion of adipocyte-derived hormones and cardiometabolic risk factors in Chinese children.

METHODS

We included 3150 school children aged 6-18 years from the Beijing Child and Adolescent Metabolic Syndrome (BCAMS) study. Data on PSE and potential confounders were collected. Six adipokines related to insulin resistance and metabolic syndrome (MetS) were measured.

RESULTS

PSE was reported in nearly two-thirds of the children. After adjusting for covariates, including age, sex, pubertal stages, lifestyle factors, and family history, PSE was independently associated with increases of 39.2% in leptin and 3.9% in retinol binding protein-4 and decreases of 11.4% in fibroblast growth factor 21 and 4.6% in adiponectin levels (p < 0.05 for all), plus risks for central obesity (OR 1.59, 95% CI 1.33-1.90), elevated blood pressure (1.22, 1.02-1.46) and MetS (1.43, 1.11-1.85). However, the associations of PSE with hypertension and MetS were abolished when adjusted for adiposity parameters or the above-mentioned adipokine profiles.

CONCLUSIONS

PSE was associated with dysregulation of adipokine levels, which might mediate the development of MetS in early life.

Childhood maltreatment and biomarkers for cardiometabolic disease in mid-adulthood in a prospective British birth cohort: associations and potential explanations

OBJECTIVES

Research on associations between childhood maltreatment and adult cardiometabolic disease risk is sparse. We aimed to investigate associations between different forms of child maltreatment and mid-adult cardiometabolic markers and whether potential intermediaries could account for the associations observed.

SETTING

1958 British birth cohort.

PARTICIPANTS

Approximately 9000 cohort members with data on cardiometabolic markers.

OUTCOMES

Adult (45y) cardiometabolic markers (blood pressure, lipids and glycated haemoglobin [HbA1c]).

RESULTS

Seventeen per cent of participants were identified as neglected; 6.1%, 1.6% and 10.0% were identified as experiencing physical, sexual and psychological abuse, respectively. Childhood neglect and physical abuse were associated with high body mass index (BMI) and large waist circumference when adjusting for early-life covariates. For neglect, the adjusted odds ratio (AOR) was 1.16 (95% CI: 1.02 to 1.32) and 1.15 (1.02 to 1.30) for general and central obesity, respectively, and for physical abuse, the respective AOR was 1.36 (1.13 to 1.64) and 1.38 (1.16 to 1.65). Neglect was also associated with raised triglycerides by 3.9 (0.3 to 7.5)% and HbA1c by 1.2 (0.4 to 2.0)%, and among females, lower high-density lipoprotein cholesterol (HDL-c) by 0.05 (0.01 to 0.08)mmol/L after adjustment. For physical abuse, the AOR was 1.25 (1.00 to 1.56) for high low-density lipoprotein cholesterol, HbA1c was raised by 2.5 (0.7 to 4.3)% (in males) and HDL-c was lower by 0.06 (0.01 to 0.12)mmol/L (in females). Associations for sexual abuse were similar to those for physical abuse but 95% CIs were wide. For psychological abuse, the AOR for elevated triglycerides was 1.21 (1.02 to 1.44) and HDL-c was lower by 0.04 (0.01 to 0.07)mmol/L. Maltreatments were not associated with raised blood pressure. In analyses of potential intermediary factors, several associations attenuated after adjustment for adult lifestyles (mainly smoking and alcohol consumption rather than physical activity) and child-to-adult BMI.

CONCLUSIONS

Childhood maltreatments, particularly neglect and physical abuse, were associated with greater adiposity and poorer lipid and HbA1c profiles decades later in adulthood. Associations were modest but independent of early-life factors linked to these outcomes. Findings implicate adult lifestyles as an important intermediary between child maltreatment and outcomes.

Smoking during pregnancy increases chemerin expression in neonatal tissue

NEW FINDINGS

What is the central question of this study? Is chemerin, an adipokine implicated in obesity, increased in neonates following in utero cigarette smoke exposure. What is the main finding and its importance? Chemerin mRNA expression was increased and chemerin DNA methylation was decreased in babies born to mothers who smoked during pregnancy. These data provide a potential mechanism that may be mediating the increased obesity risk in individuals that are born to mothers who smoked during pregnancy.

ABSTRACT

It has been shown that in utero tobacco exposure increases offspring risk for obesity, but the mechanisms responsible for this increased risk are not well understood. Chemerin is an adipokine that regulates adipocyte differentiation. This chemokine is elevated in obese individuals and with smoke exposure, but its levels have not been measured in neonates exposed to cigarette smoke in utero. We examined chemerin gene expression [n = 31 non-smoker (NS) and 15 smoker (S)] and DNA methylation (n = 28 NS and n = 11 S) in skin collected from babies born to mothers who smoked during pregnancy as compared to non-smoking controls. Quality RNA and DNA were isolated from foreskin tissue following circumcision, and chemerin gene expression and DNA methylation were assessed. Further, in a second cohort, we utilized primary dermal foreskin fibroblasts as a functional measure of adipogenesis in living cells (n = 11 NS and n = 8 S). Cells were stimulated with an adipogenic cocktail, mRNA was isolated from cells after 14 days, and chemerin gene expression assessed via real-time PCR. Chemerin mRNA was elevated in both whole tissue (NS: 2409.20 ± 555.28 counts and S: 2966.72 ± 636.84 counts; P < 0.01) and primary fibroblasts (NS: 1.12 ± <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mn>0.55</mml:mn> <mml:mspace/> <mml:msup><mml:mn>2</mml:mn> <mml:mrow><mml:mi>Δ</mml:mi> <mml:mi>Δ</mml:mi> <mml:msub><mml:mi>C</mml:mi> <mml:mi>T</mml:mi></mml:msub> </mml:mrow> </mml:msup> </mml:mrow> </mml:math> and S: 2.13 ± <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mn>1.34</mml:mn> <mml:mspace/> <mml:msup><mml:mn>2</mml:mn> <mml:mrow><mml:mi>Δ</mml:mi> <mml:mi>Δ</mml:mi> <mml:msub><mml:mi>C</mml:mi> <mml:mi>T</mml:mi></mml:msub> </mml:mrow> </mml:msup> </mml:mrow> </mml:math> ; P = 0.04) collected from infants born to smoking mothers. Chemerin DNA methylation was reduced in whole tissue of offspring born to smokers (NS: 4.18 ± 1.28 and S: 3.07 ± 1.31%; P = 0.02), which may contribute to the increased gene expression. Neonates born to mothers who smoke during pregnancy exhibit distinct changes in chemerin gene expression in response to in utero tobacco smoke exposure which are regulated in part by epigenetic alterations.

Maternal pre-eclampsia and long-term offspring health: Is there a shadow cast?

Pre-eclampsia is a common pregnancy disorder with important short-term complications for mother and baby. Evidence suggests pre-eclampsia also has implications for the mother beyond pregnancy, as well as long-term effects on offspring health. Limited research has linked pre-eclampsia with changes in offspring blood pressure, BMI, and stroke risk. Underpinning mechanisms are poorly understood, but developmental programming may be involved. Research in this area has been hindered by difficulties in defining pre-eclampsia and problems with study design. Further targeted evaluation through to adulthood is required to determine the long-term impact of pre-eclampsia on offspring disease risk and how this develops.

The impact of pre and perinatal lifestyle factors on child long term health and social outcomes: a systematic review

To understand the full extent of the impact of a trial, it is important to consider the long-term consequences of outcomes beyond the trial follow-up period, especially for early year's interventions. A systematic review of the literature associated with the long-term consequences of four key outcomes from the Building Blocks trial, specifically, low birth weight, smoking during pregnancy, interval to subsequent pregnancy and A&E attendance or inpatient admission was conducted. These factors were guided by the funders, the Department of Health, as being of particular interest in the UK context. Relevant studies were identified from a number of sources including large databases, reference checking and citation searching. The search yielded 3665 papers, 43 of which were considered appropriate for inclusion. Of these, 29 were relating to smoking during pregnancy, 13 to low birth weight, 0 to A&E attendances during early childhood and 1 to short (< 2 years) interval to subsequent pregnancy. Consistent associations were found between maternal smoking during pregnancy and the effects this has on children's health, educational attainment and likelihood of engaging in problem behaviour and criminal activity in later life. Low birth weight was also found to impact on children's long-term health and cognitive development. Subsequent pregnancies within two years of the previous birth were linked with increased likelihood of pre-term birth and neonatal death. Only minimal evidence was identified regarding the consequences of a short interval to second pregnancy and of child A&E and outpatient attendances. Given that these outcomes have been identified by the UK Department of Health as of particular interest for UK benefit, investment of research in these areas is recommended to establish a clearer picture of both short and long-term consequences.

Developmental Origins of Health Span and Life Span: A Mini-Review

BACKGROUND

A vast body of research has demonstrated that disease susceptibility and offspring health can be influenced by perinatal factors, which include both paternal and maternal behavior and environment. Offspring disease risk has the potential to affect the health span and life span of offspring.

KEY FINDINGS

Various maternal factors, such as environmental toxicant exposure, diet, stress, exercise, age at conception, and longevity have the potential to influence age-associated diseases such as cardiovascular disease, obesity, diabetes, and cancer risk in offspring. Paternal factors such as diet, age at conception, and longevity can potentially impact offspring health span and life span-reducing traits as well.

PRACTICAL IMPLICATIONS

Continued research could go a long way toward defining mechanisms of the developmental origins of life span and health span, and eventually establishing regimens to avoid negative developmental influences and to encourage positive interventions to potentially increase life span and improve health span in offspring.

Smoking and the risk of type 2 diabetes

Despite accumulating evidence demonstrating strong epidemiologic and mechanistic associations between cigarette smoking, hyperglycemia, and the development of type 2 diabetes, tobacco abuse has not been uniformly recognized as a modifiable risk factor in diabetes prevention or screening strategies. In this review, we highlight population-based studies that have linked cigarette smoking with an increased risk of type 2 diabetes and summarize clinical and preclinical studies offering insight into mechanisms through which cigarette smoking and nicotine exposure impact body composition, insulin sensitivity, and pancreatic β cell function. Key questions for future studies are identified and strategies for smoking cessation as a means to decrease diabetes risk are discussed.

Gestational hypertension is associated with increased risk of type 2 diabetes in adult offspring: the Helsinki Birth Cohort Study

BACKGROUND

Women with hypertensive disorders in pregnancy are at an increased risk of cardiovascular disease and type 2 diabetes later in life. Offspring born from these hypertensive pregnancies have increased levels of cardiovascular risk factors; whether they are at an increased risk of type 2 diabetes is not known.

OBJECTIVE

The objective of the investigation was to study the risk of type 2 diabetes in the adult offspring exposed to maternal preeclampsia or gestational hypertension in utero.

STUDY DESIGN

We studied 5335 members of the Helsinki Birth Cohort Study, who were born between 1934 and 1944 and who lived in Finland in 1995 when the National Medication Purchase Register was initiated. We ascertained gestational hypertension and preeclampsia according to modern criteria by using maternal and birth records. We defined type 2 diabetes through purchases of antidiabetic medication recorded in the comprehensive National Medication Purchase Register, excluding the 31 subjects who had purchased only insulin. We used Cox regression to assess hazard ratios for type 2 diabetes.

RESULTS

A total of 590 men (21.6%) and 433 women (16.9%) had purchased medication for diabetes. The hazard ratio for type 2 diabetes for offspring exposed to any maternal hypertension in pregnancy was 1.13 (95% confidence interval, 1.00-1.29; n = 1780). For maternal gestational hypertension, it was 1.15 (95% confidence interval, 1.00-1.33; n = 1336) and for preeclampsia 0.98 (95% confidence interval, 0.71-1.34; n = 231). For type 2 diabetes with first medication purchase before 62 years, the corresponding hazard ratios were 1.25 (95% confidence interval, 1.04-1.51); 1.28 (95% confidence interval, 1.05-1.58), and 1.18 (95% confidence interval, 0.75-1.84). The hazard ratios were similar when adjusted for birthweight SD score for gestation, length of gestation, maternal body mass index in late pregnancy, height, age, and parity and for childhood or adult socioeconomic position. An increased risk of type 2 diabetes was also associated with low birthweight SD score, independent of the association with gestational hypertension.

CONCLUSION

Offspring exposed to maternal gestational hypertension in utero have an increased risk of type 2 diabetes in late adult life. This finding underlines the role of the whole spectrum of hypertensive disorders of pregnancy as risk factors of offspring disease throughout life. It also reinforces previous suggestions that adult health care providers should incorporate birth histories when evaluating an individual's risk to develop type 2 diabetes.

Relative efficiency of joint-model and full-conditional-specification multiple imputation when conditional models are compatible: The general location model

Estimating the parameters of a regression model of interest is complicated by missing data on the variables in that model. Multiple imputation is commonly used to handle these missing data. Joint model multiple imputation and full-conditional specification multiple imputation are known to yield imputed data with the same asymptotic distribution when the conditional models of full-conditional specification are compatible with that joint model. We show that this asymptotic equivalence of imputation distributions does not imply that joint model multiple imputation and full-conditional specification multiple imputation will also yield asymptotically equally efficient inference about the parameters of the model of interest, nor that they will be equally robust to misspecification of the joint model. When the conditional models used by full-conditional specification multiple imputation are linear, logistic and multinomial regressions, these are compatible with a restricted general location joint model. We show that multiple imputation using the restricted general location joint model can be substantially more asymptotically efficient than full-conditional specification multiple imputation, but this typically requires very strong associations between variables. When associations are weaker, the efficiency gain is small. Moreover, full-conditional specification multiple imputation is shown to be potentially much more robust than joint model multiple imputation using the restricted general location model to mispecification of that model when there is substantial missingness in the outcome variable.

Early-life exposure to substance abuse and risk of type 2 diabetes in adulthood

Type 2 diabetes (T2D) is a chronic non-communicable disease that is driven by insulin resistance as a result of increasing obesity and decreasing activity levels that occur with increasing age. This disease generally develops after the age of 40, but it is now increasingly diagnosed in children and young adults. Increasing evidence, however, suggests that T2D can originate during early development. It has been repeatedly found that malnutrition during the gestational period can result in intrauterine growth restriction and low birth weight, which in combination with postnatal catch-up growth may subsequently lead to the development of T2D. There is ample evidence that T2D may also be programmed by maternal substance abuse (the harmful use of psychoactive substances such as illicit drugs or alcohol) during pregnancy and/or lactation. The research activity in this field is currently mainly focused on the childhood health problems following prenatal exposures to substance abuse. The delayed programming effects on adult-onset disorders, including metabolic syndrome and T2D, however, have been reported only rarely. This review provides animal and human evidence that early-life exposure to substance abuse, including alcohol, nicotine, and cocaine, may program not only childhood health outcomes but also life-long metabolic health status, including risk of T2D and related conditions.

The impact of prenatal parental tobacco smoking on risk of diabetes mellitus in middle-aged women

Growing evidence indicates that parental smoking is associated with risk of offspring obesity. The purpose of this study was to identify whether parental tobacco smoking during gestation was associated with risk of diabetes mellitus. This is a prospective study of 44- to 54-year-old daughters (n = 1801) born in the Child Health and Development Studies pregnancy cohort between 1959 and 1967. Their mothers resided near Oakland California, were members of the Kaiser Foundation Health Plan and reported parental tobacco smoking during an early pregnancy interview. Daughters reported physician diagnoses of diabetes mellitus and provided blood samples for hemoglobin A1C measurement. Prenatal maternal smoking had a stronger association with daughters' diabetes mellitus risk than prenatal paternal smoking, and the former persisted after adjustment for parental race, diabetes and employment (aRR = 2.4 [95% confidence intervals 1.4-4.1] P < 0.01 and aRR = 1.7 [95% confidence intervals 1.0-3.0] P = 0.05, respectively). Estimates of the effect of parental smoking were unchanged when further adjusted by daughters' birth weight or current body mass index (BMI). Maternal smoking was also significantly associated with self-reported type 2 diabetes diagnosis (2.3 [95% confidence intervals 1.0-5.0] P < 0.05). Having parents who smoked during pregnancy was associated with an increased risk of diabetes mellitus among adult daughters, independent of known risk factors, providing further evidence that prenatal environmental chemical exposures independent of birth weight and current BMI may contribute to adult diabetes mellitus. While other studies seek to confirm our results, caution toward tobacco smoking by or proximal to pregnant women is warranted in diabetes mellitus prevention efforts.

Stress and type 2 diabetes: a review of how stress contributes to the development of type 2 diabetes

Current policy and research around type 2 diabetes (T2D) interventions largely invoke a behavioral model. We suggest that activation of the physiologic stress response (PSR) from chronic exposure to stressors, low socioeconomic status (SES), severe mental health problems, or aggressive behavior increases the risk of T2D. This article is a comprehensive review of the literature on the link between T2D and psychosocial factors focusing on prospective studies of the risk for developing diabetes. The review found an increased risk for T2D in people: exposed to stressful working conditions or traumatic events; with depression; with personality traits or mental health problems that put them in conflict with others; of low SES, either currently or in childhood; and in racial/ethnic minority populations, independent of current SES. This review suggests that T2D prevention research would be more effective if (a) the PSR to psychosocial factors (especially social disparities) was recognized and (b) intervention programs evaluated reduction in social disparities as part of a comprehensive approach.

Fetal exposure to parental smoking and the risk of type 2 diabetes in adult women

OBJECTIVE

We evaluated the associations of both maternal and paternal smoking during pregnancy with the risk of type 2 diabetes in daughters and explored whether any association was explained by weight at birth or BMI throughout life.

RESEARCH DESIGN AND METHODS

We used data from 34,453 participants of the Nurses' Health Study II. We used Cox proportional hazards models to examine the associations of maternal and paternal smoking during pregnancy with incidence of type 2 diabetes in daughters between 1989 and 2009.

RESULTS

Maternal smoking during the first trimester only was associated with the risk of type 2 diabetes in the offspring, independent of confounders, birth weight, and later-life BMI (fully adjusted hazard ratio 1.34 [95% CI 1.01, 1.76]). In the age-adjusted models, both continued maternal smoking during pregnancy and paternal smoking tended to be associated with an increased risk of type 2 diabetes in daughters. Perinatal and adult life variables did not explain these associations, but additional adjustment for current BMI fully attenuated the effect estimates.

CONCLUSIONS

The associations of maternal and paternal smoking during pregnancy with the risk of type 2 diabetes in daughters were largely explained by BMI throughout the life course. Further studies are needed to explore the role of first-trimester-only maternal smoking on insulin resistance in the offspring. Also, similar effect estimates for maternal and paternal smoking suggest that the associations reflect shared family-based or lifestyle-related factors.

Intrauterine nutrition: long-term consequences for vascular health

There is a growing body of evidence that improper intrauterine nutrition may negatively influence vascular health in later life. Maternal malnutrition may result in intrauterine growth retardation and, in turn, metabolic disorders such as insulin resistance, diabetes, hypertension, and dyslipidemia, and also enhanced risk of atherosclerosis and cardiovascular death in the offspring. Energy and/or protein restriction is the most critical determinant for fetal programming. However, it has also been proposed that intrauterine n-3 fatty acid deficiency may be linked to later higher blood pressure levels and reduced insulin sensitivity. Moreover, it has been shown that inadequate supply of micronutrients such as folate, vitamin B12, vitamin A, iron, magnesium, zinc, and calcium may contribute to impaired vascular health in the progeny. In addition, hypertensive disorders of pregnancy that are linked to impaired placental blood flow and suboptimal fetal nutrition may also contribute to intrauterine growth retardation and aggravated cardiovascular risk in the offspring. On the other hand, maternal overnutrition, which often contributes to obesity and/or diabetes, may result in macrosomia and enhanced cardiometabolic risk in the offspring. Progeny of obese and/or diabetic mothers are relatively more prone to develop obesity, insulin resistance, diabetes, and hypertension. It was demonstrated that they may have permanently enhanced appetites. Their atheromatous lesions are usually more pronounced. It seems that, particularly, a maternal high-fat/junk food diet may be detrimental for vascular health in the offspring. Fetal exposure to excessive levels of saturated fatty and/or n-6 fatty acids, sucrose, fructose and salt, as well as a maternal high glycemic index diet, may also contribute to later enhanced cardiometabolic risk.

Parental smoking during pregnancy and offspring cardio-metabolic risk factors at ages 17 and 32

OBJECTIVE

To examine the association of maternal and/or paternal smoking during pregnancy with offspring cardio-metabolic risk (CMR) factors at adolescence and early adulthood, taking into account socio-demographic, medical and lifestyle characteristics of parents and offspring, as well as offspring common genetic variation.

METHODS

We used a population-based cohort of all 17 003 births in Jerusalem during 1974-76, with available archival data on parental and birth characteristics. Measurements at age 17 were assessed at military induction examinations for 11 530 offspring. 1440 offspring from the original 1974-1976 birth cohort were sampled using a stratified sampling approach, and were interviewed and examined at age 32. Parental smoking during pregnancy (i.e. maternal, paternal and any parent) was primarily defined dichotomously (any number of cigarettes smoked daily by mother or father during pregnancy vs. non-smokers). Additionally, smoking was assessed by quantity of cigarettes smoked daily. Linear regression models were used to evaluate the associations of parental smoking during pregnancy with various offspring CMR factors, after controlling for potential confounders and for genetic variation in candidate genes.

RESULTS

Prevalence of exposure to parental smoking in-utero (i.e. smoking of any parent) was 53.2% and 48.4% among the 17 years old and 32 years old samples, respectively. At age 17, smoking of at least one parent during pregnancy was significantly associated with weight (B = 1.39), height (B = 0.59), BMI (B = 0.32) and pulse rate (B = -0.78) (p-values < 0.001). At age 32, parental smoking, adjusted for covariates, was associated with 2.22 kg higher mean offspring weight, 0.95 cm higher mean offspring height, 0.57 kg/m(2) higher BMI, and 1.46 cm higher waist-circumference (p-values ≤ 0.02). Similar results, reflecting a dose response, were observed when maternal and paternal smokings were assessed by number of cigarettes smoked daily.

CONCLUSIONS

This prospective study demonstrates a potential long-term adverse effect of parental smoking during pregnancy on offspring health and calls for increasing efforts to promote smoking cessation of both parents before pregnancy.

Maternal smoking during pregnancy and daughters' risk of gestational diabetes and obesity

AIMS/HYPOTHESIS

The primary aim of the study was to investigate the risk of developing gestational diabetes in women who were exposed to tobacco smoke in utero. Secondary aims were to assess the risk of obesity and non-gestational diabetes.

METHODS

Data were retrieved from the Medical Birth Register of Sweden for women who were born in 1982 (when smoking data were first registered) or later and who had given birth to at least one child; 80,189 pregnancies were included. The associations between in utero smoking exposure (three categories: non-smokers, 1-9 cigarettes/day [moderately exposed] and >9 cigarettes/day [heavily exposed]) and subsequent gestational diabetes (n = 291), non-gestational diabetes (n = 280) and obesity (n = 7,300) were assessed.

RESULTS

The adjusted ORs (aORs) of gestational diabetes were increased among women who were moderately (1.62, 95% CI 1.24, 2.13) and heavily (1.52, 95% CI 1.12, 2.06) exposed. The corresponding aORs of obesity were 1.36 (95% CI 1.28, 1.44) and 1.58 (95% CI 1.48, 1.68), respectively. A reduced OR for non-gestational diabetes was seen in the offspring of heavy smokers (aOR 0.66, 95% CI 0.45, 0.96).

CONCLUSIONS/INTERPRETATION

Women exposed to smoking during fetal life were at higher risk of developing gestational diabetes and obesity.

Long-term health consequences of early-life exposure to substance abuse: an epigenetic perspective

A growing body of evidence highlights the importance of the nutritional or other environmental stimuli during critical periods of development in the long-term programming of organ systems and homeostatic pathways of the organism. The adverse influences early in development and particularly during intrauterine life have been shown to programme the risks for adverse health outcomes in adult life. The mechanisms underlying developmental programming remain still unclear. However, increasing evidence has been accumulated indicating the important role of epigenetic regulation including DNA methylation, histone modifications and non-coding RNAs in the developmental programming of late-onset pathologies, including cancer, neurodegenerative diseases, and type 2 diabetes. The maternal substance abuse during pregnancy, including smoking, drinking and psychoactive drug intake, is one of the important factors determining the process of developmental programming in modern human beings. The impact of prenatal drug/substance exposure on infant and early childhood development is currently in the main focus. The long-term programming effects of such exposures on aging and associated pathologies, however, have been reported only rarely. The purpose of this review is to provide a summary of recent research findings which indicate that maternal substance abuse during pregnancy and/or neonatal period can programme not only a child's health status, but also can cause long-term or even life-long health outcomes via mechanisms of epigenetic memory.

Evaluation of the association between maternal smoking, childhood obesity, and metabolic disorders: a national toxicology program workshop review

BACKGROUND

An emerging literature suggests that environmental chemicals may play a role in the development of childhood obesity and metabolic disorders, especially when exposure occurs early in life.

OBJECTIVE

Here we assess the association between these health outcomes and exposure to maternal smoking during pregnancy as part of a broader effort to develop a research agenda to better understand the role of environmental chemicals as potential risk factors for obesity and metabolic disorders.

METHODS

PubMed was searched up to 8 March 2012 for epidemiological and experimental animal studies related to maternal smoking or nicotine exposure during pregnancy and childhood obesity or metabolic disorders at any age. A total of 101 studies-83 in humans and 18 in animals-were identified as the primary literature.

DISCUSSION

Current epidemiological data support a positive association between maternal smoking and increased risk of obesity or overweight in offspring. The data strongly suggest a causal relation, although the possibility that the association is attributable to unmeasured residual confounding cannot be completely ruled out. This conclusion is supported by findings from laboratory animals exposed to nicotine during development. The existing literature on human exposures does not support an association between maternal smoking during pregnancy and type 1 diabetes in offspring. Too few human studies have assessed outcomes related to type 2 diabetes or metabolic syndrome to reach conclusions based on patterns of findings. There may be a number of mechanistic pathways important for the development of aberrant metabolic outcomes following perinatal exposure to cigarette smoke, which remain largely unexplored.

CONCLUSIONS

From a toxicological perspective, the linkages between maternal smoking during pregnancy and childhood overweight/obesity provide proof-of-concept of how early-life exposure to an environmental toxicant can be a risk factor for childhood obesity.

Early markers of adult obesity: a review

The purpose of this review was to evaluate factors in early childhood (≤5 years of age) that are the most significant predictors of the development of obesity in adulthood. Factors of interest included exposures/insults in the prenatal period, infancy and early childhood, as well as other socio-demographic variables such as socioeconomic status (SES) or birth place that could impact all three time periods. An extensive electronic and systematic search initially resulted in 8,880 citations, after duplicates were removed. Specific inclusion and exclusion criteria were set, and following two screening processes, 135 studies were retained for detailed abstraction and analysis. A total of 42 variables were associated with obesity in adulthood; however, of these, only seven variables may be considered as potential early markers of obesity based on the reported associations. Possible early markers of obesity included maternal smoking and maternal weight gain during pregnancy. Probable early markers of obesity included maternal body mass index, childhood growth patterns (early rapid growth and early adiposity rebound), childhood obesity and father's employment (a proxy measure for SES in many studies). Health promotion programmes/agencies should consider these factors as reasonable targets to reduce the risk of adult obesity.

In utero exposure to maternal tobacco smoke and subsequent obesity, hypertension, and gestational diabetes among women in the MoBa cohort

BACKGROUND

Environmental factors influencing the developmental origins of health and disease need to be identified and investigated. In utero exposure to tobacco smoke has been associated with obesity and a small increase in blood pressure in children; however, whether there is a corresponding increased risk of conditions such as diabetes and hypertension during adulthood remains unclear.

OBJECTIVE

Our goal was to assess the association of self-reported in utero exposure to tobacco smoke with the prevalence of obesity, hypertension, type 2 diabetes mellitus (T2DM), and gestational diabetes mellitus (GDM) in women 14-47 years of age.

METHODS

We conducted a cross-sectional analysis of the Norwegian Mother and Child Cohort Study, which enrolled pregnant women in Norway from 1999 thorough 2008. Exposure to tobacco smoke in utero (yes vs. no) was ascertained on the baseline questionnaire (obtained at ~ 17 weeks' gestation); the outcomes were ascertained from the Medical Birth Registry of Norway and the questionnaire. Our analysis included 74,023 women.

RESULTS

Women exposed to tobacco smoke in utero had 1.53 times the odds of obesity [95% confidence interval (CI): 1.45, 1.61] relative to those unexposed, after adjusting for age, education, and personal smoking. After further adjustment for body mass index, the odds ratio for hypertension was 1.68 (95% CI: 1.19, 2.39); for T2DM 1.14 (95% CI: 0.79, 1.65); and for GDM 1.32 (95% CI: 1.10, 1.58) among exposed compared with unexposed.

CONCLUSIONS

Exposure to tobacco smoke in utero was associated with obesity, hypertension, and GDM in adult women. The possibility that the associations were attributable to unmeasured confounding cannot be excluded.

Combining multiple imputation and inverse-probability weighting

Two approaches commonly used to deal with missing data are multiple imputation (MI) and inverse-probability weighting (IPW). IPW is also used to adjust for unequal sampling fractions. MI is generally more efficient than IPW but more complex. Whereas IPW requires only a model for the probability that an individual has complete data (a univariate outcome), MI needs a model for the joint distribution of the missing data (a multivariate outcome) given the observed data. Inadequacies in either model may lead to important bias if large amounts of data are missing. A third approach combines MI and IPW to give a doubly robust estimator. A fourth approach (IPW/MI) combines MI and IPW but, unlike doubly robust methods, imputes only isolated missing values and uses weights to account for remaining larger blocks of unimputed missing data, such as would arise, e.g., in a cohort study subject to sample attrition, and/or unequal sampling fractions. In this article, we examine the performance, in terms of bias and efficiency, of IPW/MI relative to MI and IPW alone and investigate whether the Rubin's rules variance estimator is valid for IPW/MI. We prove that the Rubin's rules variance estimator is valid for IPW/MI for linear regression with an imputed outcome, we present simulations supporting the use of this variance estimator in more general settings, and we demonstrate that IPW/MI can have advantages over alternatives. IPW/MI is applied to data from the National Child Development Study.

Early markers of adult obesity: a review

The purpose of this review was to evaluate factors in early childhood (≤5 years of age) that are the most significant predictors of the development of obesity in adulthood. Factors of interest included exposures/insults in the prenatal period, infancy and early childhood, as well as other socio-demographic variables such as socioeconomic status (SES) or birth place that could impact all three time periods. An extensive electronic and systematic search initially resulted in 8,880 citations, after duplicates were removed. Specific inclusion and exclusion criteria were set, and following two screening processes, 135 studies were retained for detailed abstraction and analysis. A total of 42 variables were associated with obesity in adulthood; however, of these, only seven variables may be considered as potential early markers of obesity based on the reported associations. Possible early markers of obesity included maternal smoking and maternal weight gain during pregnancy. Probable early markers of obesity included maternal body mass index, childhood growth patterns (early rapid growth and early adiposity rebound), childhood obesity and father's employment (a proxy measure for SES in many studies). Health promotion programmes/agencies should consider these factors as reasonable targets to reduce the risk of adult obesity.

Changes in BMI, duration of overweight and obesity, and glucose metabolism: 45 years of follow-up of a birth cohort

OBJECTIVE

Long-term implications of childhood obesity and BMI change over the life course for risk of type 2 diabetes remain uncertain. The objective was to establish whether there are effects on adult glucose metabolism of 1) sensitive periods of BMI gain or 2) long duration of overweight and obesity.

RESEARCH DESIGN AND METHODS

Participants in the 1958 British birth cohort with child to adult BMI and glycosylated hemoglobin (HbA(1c)) at 45 years (n = 7,855).

RESULTS

Prevalence of type 2 diabetes or HbA(1c) ≥7 was 2%. BMI gains in child- and adulthood were associated with higher HbA(1c): for every SD of 5-year BMI increase from 0 to 7 years, there was a 75% (95% CI 1.42-2.16) increased risk of HbA(1c) ≥7, increasing to a 4.7-fold (3.12-7.00) risk for the interval 23-33 years. Associations for BMI gain in adulthood were related to attained BMI but were independent for the longer period birth (or 7 years) to 45 years. Duration of obesity was also associated with HbA(1c); compared with the never obese, those with childhood onset had a 23.9-fold risk (13.5-42.1) of HbA(1c) ≥7%; odds ratios were 16.0 (10.6-24.2) and 2.99 (1.77-5.03), respectively, for young and midadulthood onset. Similar trends by onset age were found in mean HbA(1c) levels and for onset of overweight. Those with the earliest age of onset had higher BMI and waist circumference at 45 years, which markedly explained the associations for onset age and HbA(1c).

CONCLUSIONS

Excessive BMI gain across the life span and earlier onset of overweight/obesity are associated with impaired glucose metabolism, in part through attained adult BMI.

Prepregnancy body mass index, smoking during pregnancy, and infant birth weight

PURPOSE

Smoking during pregnancy is strongly associated with increased risk of small for gestational age (SGA) and low birth weight, whereas elevated prepregnancy body mass index (BMI) is associated with a decreased risk of SGA and greater birth weight. We investigated the combined effect of prenatal smoking and prepregnancy BMI on risk of SGA and on birth weight.

METHODS

A total of 34,928 singleton, term pregnancies in residents of New York City between 1995 and 2003 were evaluated in multivariable regression models of birth weight and risk of SGA.

RESULTS

Increasing prepregnancy BMI reduced the risk of SGA and increased birth weight. The effect of prenatal smoking on birth weight and SGA diminished in women as their prepregnancy BMI increased, such that prenatal smoking did not significantly impact the risk of SGA among women who were overweight or obese before pregnancy. Prenatal smoking decreased mean birth weight by 187 g (95% confidence interval [CI] -337, -37) among underweight women, by 129 g(95% CI -170, -87) among normal weight women, by 46 g (95% CI -113, +20) among overweight women, and by 75 g (95% CI -162, +11) among obese women.

CONCLUSIONS

This study suggests that the effect of smoking during pregnancy on SGA and birth weight is present in underweight and normal weight women but markedly reduced among obese and overweight women.

Review of inverse probability weighting for dealing with missing data

The simplest approach to dealing with missing data is to restrict the analysis to complete cases, i.e. individuals with no missing values. This can induce bias, however. Inverse probability weighting (IPW) is a commonly used method to correct this bias. It is also used to adjust for unequal sampling fractions in sample surveys. This article is a review of the use of IPW in epidemiological research. We describe how the bias in the complete-case analysis arises and how IPW can remove it. IPW is compared with multiple imputation (MI) and we explain why, despite MI generally being more efficient, IPW may sometimes be preferred. We discuss the choice of missingness model and methods such as weight truncation, weight stabilisation and augmented IPW. The use of IPW is illustrated on data from the 1958 British Birth Cohort.

In utero exposure to maternal smoking and women's risk of fetal loss in the Norwegian Mother and Child Cohort (MoBa)

BACKGROUND

Whether in utero exposure to tobacco smoke increases a woman's risk of fetal loss later in life is unknown, though data on childhood exposure suggest an association may exist. This study evaluated the association between in utero exposure to tobacco smoke and fetal loss in the Norwegian Mother and Child Cohort Study (MoBa), which enrolled ∼40% of the pregnant women in Norway from 1999 to 2008.

METHODS

Information on exposure to tobacco smoke in utero, the woman's own smoking behavior during pregnancy and other factors was obtained by a questionnaire completed at ∼17 weeks of gestation. Subsequent late miscarriage (fetal death <20 weeks) and stillbirth (fetal death ≥ 20 weeks) were ascertained from the Norwegian Medical Birth Registry. This analysis included 76 357 pregnancies (MoBa data set version 4.301) delivered by the end of 2008; 59 late miscarriages and 270 stillbirths occurred. Cox proportional hazards models were fit for each outcome and for all fetal deaths combined.

RESULTS

The adjusted hazard ratio (HR) of late miscarriage was 1.23 [95% confidence interval (CI), 0.72-2.12] in women with exposure to maternal tobacco smoke in utero when compared with non-exposed women. The corresponding adjusted HR for stillbirths was 1.11 (95% CI, 0.85-1.44) and for all fetal deaths combined, it was 1.12 (95% CI, 0.89-1.43).

CONCLUSIONS

The relatively wide CI around the HR for miscarriage reflected the limited power to detect an association, due to enrollment around 17 weeks of gestation. However, for in utero exposure to tobacco smoke and risk of stillbirth later in life, where the study power was adequate, our data provided little support for an association.

Maternal smoking in pregnancy, adult adiposity and other risk factors for cardiovascular disease

OBJECTIVE

To establish whether maternal smoking in pregnancy is associated with risk factors for cardiovascular disease (CVD) in mid-adulthood and whether associations are explained by postnatal influences.

METHODS

Participants were 8815 men and women in the 1958 British birth cohort, with data on CVD risk factors measured at 45 y. Maternal smoking was recorded at birth.

RESULTS

Offspring of smokers had a higher adult BMI, waist circumference, blood pressure, HbA1c and triglycerides on average than offspring of non-smokers; females had lower HDL cholesterol levels. Total cholesterol was unrelated to maternal smoking. Associations were abolished after adjustment for postnatal influences across life, except for BMI and waist circumference: offspring of smokers had a BMI greater by 0.83 kg/m(2) on average than offspring of non-smokers and a 1.8 cm larger waist circumference. Mean BMI and waist circumference increased with number of cigarettes that the mother smoked, but were not elevated in offspring whose mother had quit smoking before or early in pregnancy.

CONCLUSIONS

Adults exposed to tobacco in utero had a more adverse CVD risk profile in mid-adulthood which appeared to reflect a lifetime accumulation of postnatal influences; whereas their higher BMI and central adiposity may be due in part to intrauterine mechanisms.

Protocol of the baseline assessment for the Environments for Healthy Living (EHL) Wales cohort study

BACKGROUND

Health is a result of influences operating at multiple levels. For example, inadequate housing, poor educational attainment, and reduced access to health care are clustered together, and are all associated with reduced health. Policies which try to change individual people's behaviour have limited effect when people have little control over their environment. However, structural environmental change and an understanding of the way that influences interact with each other, has the potential to facilitate healthy choices irrespective of personal resources. The aim of Environments for Healthy Living (EHL) is to investigate the impact of gestational and postnatal environments on health, and to examine where structural change can be brought about to optimise health outcomes. The baseline assessment will focus on birth outcomes and maternal and infant health.

METHODS/DESIGN

EHL is a longitudinal birth cohort study. We aim to recruit 1000 pregnant women in the period April 2010 to March 2013. We will examine the impact of the gestational environment (maternal health) and the postnatal environment (housing and neighbourhood conditions) on subsequent health outcomes for the infants born to these women. Data collection will commence during the participants' pregnancy, from approximately 20 weeks gestation. Participants will complete a questionnaire, undergo anthropometric measurements, wear an accelerometer, compile a food diary, and have environmental measures taken within their home. They will also be asked to consent to having a sample of umbilical cord blood taken following delivery of their baby. These data will be complemented by routinely collected electronic data such as health records from GP surgeries, hospital admissions, and child health and development records. Thereafter, participants will be visited annually for follow-up of subsequent exposures and child health outcomes.

DISCUSSION

The baseline assessment of EHL will provide information concerning the impact of gestational and postnatal environments on birth outcomes and maternal and infant health. The findings can be used to inform the development of complex interventions targeted at structural, environmental factors, intended to reduce ill-health. Long-term follow-up of the cohort will focus on relationships between environmental exposures and the later development of adverse health outcomes, including obesity and diabetes.

Risks and management of obesity in pregnancy: current controversies

PURPOSE OF REVIEW

To explore recent developments in obesity-related topics of interest and importance to obstetricians. Specifically addressed are the impact of gestational weight gain on perinatal risk, the increased risk of congenital anomalies in offspring, developmental origins of health and disease in offspring, and reproductive issues following bariatric surgery.

RECENT FINDINGS

Limiting maternal weight gain in obese women to less than 15 lb may favorably attenuate perinatal risk (macrosomia, cesarean delivery, preeclampsia) but increase risk for small-for-gestational-age newborns. Obese women are at significantly increased risk for offspring to develop open neural tube defects and congenital heart disease as well as other anomalies. Impaired sonographic visualization in this population may impede prenatal diagnosis of these serious birth defects. Intrauterine nutritional overabundance may cue adaptive fetal responses predisposing to childhood and adult obesity as well as the metabolic syndrome. Bariatric surgery, the only effective treatment for morbid obesity, causes lifelong physiologic and anatomic changes associated with significant reproductive implications. Procedures can predispose to caloric and micronutrient deficiencies, improved fertility and fecundity, and late surgical complications. Pregnancy outcomes are typically similar to those of women without previous bariatric surgery and better than those of untreated morbidly obese women.

SUMMARY

Obesity and its surgical treatment are associated with lifelong health implications for the mother as well as her offspring. An appreciation of these obesity-related reproductive issues is critical for optimal care of this growing segment of the female population.

Do early life exposures explain associations in mid-adulthood between workplace factors and risk factors for cardiovascular disease?

BACKGROUND

Workplace factors (night work, long working hours, psychosocial work stress) have been reported to be associated with increased risk of cardiovascular disease (CVD). We investigated whether (i) workplace factors are associated with CVD risk factors independently of each other, (ii) workplace factors interact, thereby modifying associations and (iii) associations are explained by early life exposures.

METHODS

A total of 7916 employed participants in the 1958 British birth cohort underwent a clinical assessment at age 45 years. Regression analysis was used to examine associations between workplace factors and CVD risk factor levels with adjustment for early life exposures.

RESULTS

Night work was associated with adverse levels of most CVD risk factors. Working > or =48 h/week was positively associated with body mass index (BMI) and waist circumference (WC). Low job control was positively associated with glycosylated haemoglobin (HbA1c) and inflammatory factors, and inversely associated with high-density lipoprotein (HDL)-cholesterol. Low demands were positively associated with systolic blood pressure (SBP), triglycerides and inflammatory factors and inversely associated with HDL-cholesterol. Several associations were weakened when workplace factors were adjusted for each other. Night workers in low-demand jobs had higher BMI [0.78 kg/m(2); 95% confidence interval (CI) 0.35, 1.21], WC (1.49 cm; 0.45, 2.52) and SBP (1.38 mmHg; -0.04, 2.81). HDL was lower for low control plus night work (-0.04 mmol/l; -0.08, -0.01) or long hours (-0.12; -0.18, -0.69). Adjustment for early life exposures explained 30-50% of most associations, e.g. night work/low demands associations reduced by 50% for BMI and WC, and by 39% for SBP.

CONCLUSIONS

Associations between workplace factors and CVD risk factors in mid-adulthood arise in part from social and health disadvantage originating earlier in life.

Fetal environment and early age at natural menopause in a British birth cohort study

BACKGROUND

Early life development may influence the timing of natural menopause through association with size of the initial follicle pool or early follicular loss. This study examines the relationships of birthweight, gestational age and birthweight standardized by gestational age with early menopause in the 1958 British birth cohort study.

METHODS

Study participants were over 2900 women with data on birthweight, gestational age (obtained at birth), menopausal status at age 44-45 years and potential confounding factors. Logistic regression was used to study relationships of birthweight, gestational age and birthweight standardized by gestational age with post-menopausal status by 44-45 years, with and without adjustments for confounding factors.

RESULTS

There was a U-shaped association between birthweight and menopausal status at 44-45 years: women at either extremes of birthweight (<2.5 and >or=4.0 kg) had increased odds of post-menopausal status compared with those weighing 3.0-3.49 kg [odds ratio (OR) = 1.91, 95% confidence interval (CI) 1.08, 3.38; 1.81, 95% CI 1.11, 2.97, respectively]. Women with higher birthweight standardized by gestational age (which indicates faster fetal growth rate) also had increased odds of being post-menopausal by 44-45 years (OR for fastest quarter versus second fastest quarter = 1.80; 95% CI 1.16, 2.81). These associations persisted after adjustment for socioeconomic position at birth, adult smoking status and use of oral contraceptives.

CONCLUSIONS

These findings suggest that variations in fetal environment may be associated with the timing of menopause. Given that extremes of birthweight and higher birthweight standardized by gestational age were associated with earlier age at menopause, mechanisms related to these characteristics that also regulate ovarian function should be investigated further.

Associations between childhood socioeconomic position and adulthood obesity

Childhood socioeconomic position (SEP) is inversely associated with cardiovascular disease and all-cause mortality. Obesity in adulthood may be a biologic mechanism. Objectives were to systematically review literature published between 1998 and 2008 that examined associations of childhood SEP with adulthood obesity. Five databases (Cochrane Library, MEDLINE, EMBASE, PsycINFO, Web of Science) were searched for studies from any country, in any language. Forty-eight publications based on 30 studies were identified. In age-adjusted analyses, inverse associations were found between childhood SEP and adulthood obesity in 70% (14 of 20) of studies in females and 27% (4 of 15) in males. In studies of females showing inverse associations between childhood SEP and adulthood obesity, typical effect sizes in age-adjusted analyses for the difference in body mass index between the highest and lowest SEP were 1.0-2.0 kg/m(2); for males, effect sizes were typically 0.2-0.5 kg/m(2). Analyses adjusted for age and adult SEP showed inverse associations in 47% (8 of 17) of studies in females and 14% (2 of 14) of studies in males. When other covariates were additionally adjusted for, inverse associations were found in 4 of 12 studies in females and 2 of 8 studies in males; effect sizes were typically reduced compared with analyses adjusted for age only. In summary, the findings suggest that childhood SEP is inversely related to adulthood obesity in females and not associated in males after adjustment for age. Adulthood SEP and other obesity risk factors may be the mechanisms responsible for the observed associations between childhood SEP and adulthood obesity.

Childhood socioeconomic position, gender, adult body mass index, and incidence of type 2 diabetes mellitus over 34 years in the Alameda County Study

OBJECTIVES

We examined the association between childhood socioeconomic position and incidence of type 2 diabetes and the effects of gender and adult body mass index (BMI).

METHODS

We studied 5913 participants in the Alameda County Study from 1965 to 1999 who were diabetes free at baseline (1965). Cox proportional hazards models estimated diabetes risk associated with childhood socioeconomic position and combined childhood socioeconomic position-adult BMI categories in pooled and gender-stratified samples. Demographic confounders and potential pathway components (physical inactivity, smoking, alcohol consumption, hypertension, depression, health care access) were included as covariates.

RESULTS

Low childhood socioeconomic position was associated with excess diabetes risk, especially among women. Race and body composition accounted for some of this excess risk. The association between childhood socioeconomic position and diabetes incidence differed by adult BMI category in the pooled and women-only groups. Adjustment for race and behaviors attenuated the risk attributable to low childhood socioeconomic position among the obese group only.

CONCLUSIONS

Childhood socioeconomic position was a robust predictor of incident diabetes, especially among women. A cumulative risk effect was observed for both childhood socioeconomic position and adult BMI, especially among women.

Obesity and type 2 diabetes risk in midadult life: the role of childhood adversity

OBJECTIVE

Child abuse has been associated with poorer physical health in adulthood, but less is known about childhood adversity more broadly, including neglect and family problems, or the pathways from adversity to adult disease. We have examined how different stressful emotional or neglectful childhood adversities are related to adiposity and glucose control in midadulthood, taking into account childhood factors, and whether the relationships are mediated by adult health behaviors and socioeconomic position.

METHODS

This was a prospective longitudinal study of 9310 members of the 1958 British birth cohort who participated in a biomedical interview at 45 years of age. Primary outcomes consisted of continuous measures of BMI, waist circumference, and glycosylated hemoglobin at 45 years and categorical indicators: total obesity (BMI > or = 30), central obesity (waist circumference: > or = 102 cm for men and > or = 88 cm for women), and glycosylated hemoglobin level of > or = 6.

RESULTS

The risk of obesity increased by 20% to 50% for several adversities (physical abuse, verbal abuse, witnessed abuse, humiliation, neglect, strict upbringing, physical punishment, conflict or tension, low parental aspirations or interest in education, hardly takes outings with parents, and father hardly reads to child). Adversities with the strongest associations with adiposity (eg, physical abuse) tended to be associated with glycosylated hemoglobin levels of > or = 6, but in most cases associations were explained by adjustment for adulthood mediators such as adiposity. Effects of other adversities reflecting less severe emotional neglect and family environment were largely explained by childhood socioeconomic factors.

CONCLUSIONS

Some childhood adversities increase the risk of obesity in adulthood and thereby increase the risk for type 2 diabetes. Research is needed to understand the interrelatedness of adversities, the social context of their occurrence, and trajectories from adversity to adult disease.