Sex and gender differences in developmental programming of metabolism

High Maternal Omega-3 Supplementation Dysregulates Body Weight and Leptin in Newborn Male and Female Rats: Implications for Hypothalamic Developmental Programming

Maternal diet is critical for offspring development and long-term health. Here we investigated the effects of a poor maternal diet pre-conception and during pregnancy on metabolic outcomes and the developing hypothalamus in male and female offspring at birth. We hypothesised that offspring born to dams fed a diet high in fat and sugar (HFSD) peri-pregnancy will have disrupted metabolic outcomes. We also determined if these HFSD-related effects could be reversed by a shift to a healthier diet post-conception, in particular to a diet high in omega-3 polyunsaturated fatty acids (ω3 PUFAs), since ω3 PUFAs are considered essential for normal neurodevelopment. Unexpectedly, our data show that there are minimal negative effects of maternal HFSD on newborn pups. On the other hand, consumption of an ω3-replete diet during pregnancy altered several developmental parameters. As such, pups born to high-ω3-fed dams weighed less for their length, had reduced circulating leptin, and also displayed sex-specific disruption in the expression of hypothalamic neuropeptides. Collectively, our study shows that maternal intake of a diet rich in ω3 PUFAs during pregnancy may be detrimental for some metabolic developmental outcomes in the offspring. These data indicate the importance of a balanced dietary intake in pregnancy and highlight the need for further research into the impact of maternal ω3 intake on offspring development and long-term health.

Birth weight and body composition in 6-to-8 years old Maya children

OBJECTIVE

To test the hypothesis that fetal growth, indexed by birth weight (BW), induce metabolic adjustments in the fetus that will be reflected in differences in body composition in a sample of 6-to 8-years old urban Maya children from Yucatan, Mexico.

METHODS

We measured height (cm), weight (kg) and triceps skinfold (mm) in 260 children (boys: 132, girls: 128), and height (cm) and weight (kg) in their mothers. Body composition was estimated in children through bioelectrical impedance analysis. Outcome variables were fat free-mass index (FFMI = fat-free mass [kg]/height [m]² ) and fat mass index (FMI = fat mass [kg]/height [m]² ). The main independent variable was BW z-scores. Multiple linear regression models were used to analyze the association between BW z-scores and outcome variables measured during childhood. Separate analyses were done for boys and girls. Complementary models were run using outcomes as z-scores. Models were adjusted for location, children's and mothers' age, mother's body mass index and household overcrowding index.

RESULTS

BW in boys was positively associated with FFMI and FMI. FFMI increase 0.34 kg/m² per 1-SD increase in BW and FMI increase 0.40 kg/m² per 1-SD increase in BW. When outcomes were used as z-scores, FFMI increase 0.24 SD and FMI increase 0.18 SD per 1-SD increase in BW, respectively.

CONCLUSION

Our results are in contrast with previous findings that birth weight is more consistently associated with subsequent lean mass than with fat mass. Associations, detected only in boys, may be explained by sex differences in sensitivity to early life environments.

Western Diet: Implications for Brain Function and Behavior

The Western diet (WD) pattern characterized by high daily intake of saturated fats and refined carbohydrates often leads to obesity and overweight, and it has been linked to cognitive impairment and emotional disorders in both animal models and humans. This dietary pattern alters the composition of gut microbiota, influencing brain function by different mechanisms involving the gut-brain axis. In addition, long-term exposure to highly palatable foods typical of WD could induce addictive-like eating behaviors and hypothalamic-pituitary-adrenal (HPA) axis dysregulation associated with chronic stress, anxiety, and depression. In turn, chronic stress modulates eating behavior, and it could have detrimental effects on different brain regions such as the hippocampus, hypothalamus, amygdala, and several cortical regions. Moreover, obesity and overweight induce neuroinflammation, causing neuronal dysfunction. In this review, we summarize the current scientific evidence about the mechanisms and factors relating WD consumption with altered brain function and behavior. Possible therapeutic interventions and limitations are also discussed, aiming to tackle and prevent this current pandemic.

Whey Versus Casein as a Protein Source during the Weaning Period: Impact on Growth and Later Adiposity and Glucose Homeostasis in a Rat Model of Intrauterine Growth Restriction

The impact of early life protein source (whey vs. casein) on short- and long-term glucose homeostasis and adiposity is unknown and was investigated in this study. At the end of the suckling period, non-IUGR (intrauterine growth restriction) and IUGR pups were separated from dams and were randomized into four groups. From age 21-49 days, non-IUGR and IUGR pups were fed ad-libitum chow or a semi-synthetic diet (20% from protein; casein or whey) and from age 50-199 days, all groups were fed ad-libitum chow. Food intake, body composition, glucose, and insulin homeostasis were assessed. Among the chow groups, IUGR had slower growth and higher fasting glucose at age 42 days, as well as higher fasting and AUC glucose at age 192 days relative to non-IUGR. The whey IUGR group had a slower growth rate and higher fasting glycemia in early life (age 21-49 days) and higher HOMA-IR later in life (age 120-122 and 190-192 days) relative to casein IUGR. This study shows the potential advantage of casein relative to whey during weaning on short term energy intake, growth, and glucose homeostasis in an IUGR model and reveals, for the first time, its long term impact on insulin sensitivity, which may have implications for later metabolic health, particularly in small-for-gestational-age populations at risk of type 2 diabetes.

Gestational Cytokines and the Developmental Expression of Obesity in Childhood

OBJECTIVE

This study examined the extent to which maternal immune activity during pregnancy is associated with childhood adiposity, and if so, whether associations at birth differ from those in infancy and childhood. Sex-specific associations were also examined.

METHODS

Participants were 1,366 singleton pregnancies from the Collaborative Perinatal Project (1959-1966). Interleukin-1β (IL-1β), IL-6, TNF-α, IL-8, and IL-10 in maternal sera were assayed repeatedly during pregnancy. Children's BMI was calculated repeatedly from birth through age 8 and derived age- and sex-normalized BMI z scores (BMIz). Linear mixed models were used to estimate the cumulative concentration of each cytokine in the second and third trimesters and then related this concentration to child BMIz.

RESULTS

Children exposed to higher IL-1β, IL-6, IL-8, and IL-10 concentrations had lower BMIz at birth but higher BMIz during childhood. Higher concentrations of IL-8 and IL-1β were also associated with higher BMIz during infancy (B per log increase in IL-8 = 0.04; 95% CI: 0.02 to 0.07; B per log increase in IL-1β = 0.03; 95% CI: 0.001 to 0.06). The associations between TNF-α and BMIz were in opposing directions in boys (B = -0.13; 95% CI: -0.31 to 0.04) and girls (B = 0.14; 95% CI: 0.02 to 0.26) during childhood.

CONCLUSIONS

Maternal prenatal inflammation contributes to the age- and sex-specific programming of obesity risk in childhood.

Breakfast skipping and overweight/obesity in first grade primary school children: A nationwide register-based study in Iceland

Although several studies have revealed an association between skipping breakfast and overweight (OW) or obesity (OB) in older children and adolescents, less is known about that association in younger children. The purpose of our study was to assess the association between skipping breakfast and OW/OB in children in the first grade. The sample included 4360 children (51.5% boys) aged 5.6 to 7.4 years who participated in the annual health examination in Iceland during 2016 and 2017, completed by 91% of all first graders in Iceland. Binary logistic regression analysis with odds ratios (ORs) and 95% confidence intervals (CIs) was used to assess the association between skipping breakfast and OW/OB. Skipping breakfast was assessed as not eating breakfast on the day of the assessment, whereas OW or OB was based on measured height and weight relative to the International Obesity Task Force reference. The final analyses were adjusted for bedtime, well-being in school, commuting to school and physical activity. 7.2% of the boys (n = 162) and 7.5% of the girls (n = 158) had not eaten breakfast. After multivariable adjustment, a statistically significant association emerged between skipping breakfast and OW/OB in girls (OR 1.66, 95% CI 1.17-2.36) but not in boys (OR 1.02, 95% CI 0.63-1.63). Because the study's results suggest an association between skipping breakfast and OW/OB only in first-grade girls in Iceland, sex-based differences should be further investigated to inform future strategies for preventing OW and OB in young children.

Maternal High-Fat-High-Carbohydrate Diet-Induced Obesity Is Associated with Increased Appetite in Peripubertal Male but Not Female C57Bl/6J Mice

Diet-induced maternal obesity might play a critical role in altering hypothalamic development, predisposing the offspring to obesity and metabolic disease later in life. The objective of this study was to describe both phenotypic and molecular sex differences in peripubertal offspring energy homeostasis, using a mouse model of maternal obesity induced by a high-fat-high-carbohydrate (HFHC) diet. We report that males, not females, exposed to a maternal HFHC diet had increased energy intake. Males exposed to a maternal HFHC diet had a 15% increased meal size and a 46% increased frequency, compared to the control (CON) males, without a change in energy expenditure. CON and HFHC offspring did not differ in body weight, composition, or plasma metabolic profile. HFHC diet caused decreased hypothalamic glucocorticoid expression, which was further decreased in males compared to females. Maternal weight, maternal caloric intake, and male offspring meal frequency were inversely correlated with offspring hypothalamic insulin receptor (IR) expression. There was a significant interaction between maternal-diet exposure and sex in hypothalamic IR. Based on our preclinical data, we suggest that interventions focusing on normalizing maternal nutrition might be considered to attenuate nutritional influences on obesity programming and curb the continuing rise in obesity rates.

Gestational Diabetes Mellitus Affects Offspring's Epigenome. Is There a Way to Reduce the Negative Consequences?

Gestational diabetes mellitus (GDM) is the most common pregnancy complication worldwide and may result in short-term and long-term consequences for offspring. The present review highlights evidence of epigenetic programming, mostly from human studies, which occurs in offspring exposed to maternal GDM during different stages of development, paying special attention to the differences in sensitivity of offspring to maternal hyperglycemia as a result of sex-related factors. We also aim to answer the following question: If these epigenetic changes are constant throughout the lifetime of the offspring, how do they present phenotypically?

Metabolic and behavioural effects in offspring exposed to maternal sucrose consumption: a systematic review and meta-analysis of data from rodent models

Consumption of sugar-sweetened beverages (SSBs) during pregnancy has been associated with childhood obesity. Research in which rodent dams have been given high-fat/high-sugar diets has consistently found metabolic alterations in their offspring. However, what remains unclear is the potential impact on the developing fetus of giving sugar in isolation at concentrations similar to SSBs to the mothers. Therefore, we conducted a systematic review and meta-analysis (Protocol No: 127115 on Prospero) to identify potential relationships between maternal sucrose consumption and metabolic outcomes in offspring of rodent (rat or mouse) models. We analysed studies that provided rodent mothers dams with access to sucrose solutions (8-20% w/v) prior to conception, during pregnancy and/or lactation and that reported offspring outcomes of body weight (BW), body composition and glycaemic control. Following a systematic search of four databases (PubMed, EMBASE, Web of Science and Scopus) performed on 15 January 2019, maternal and offspring data from 15 papers were identified for inclusion. Only rat studies were identified. Meta-analyses were performed on standardised mean differences for maternal and offspring BW and fasting glucose levels, with subgroup analyses of strain, sucrose concentration, exposure period and sex of offspring. A bias towards the inclusion of only data from male offspring was identified and this limited interpretation of potential sexually dimorphic outcomes. Maternal sucrose exposure was associated with an increased risk of obesity and poor glucose disposal in adult and aged offspring.

Developmental programming of peripheral diseases in offspring exposed to maternal obesity during pregnancy

Obesity is an increasing global health epidemic that affects all ages, including women of reproductive age. During pregnancy, maternal obesity is associated with adverse pregnancy outcomes that lead to complications for the mother. In addition, maternal obesity can increase the risk of poor perinatal outcomes for the infant due to altered development. Recent research has investigated the effects of maternal obesity on peripheral organ development and health in later life in offspring. In this review, we have summarized studies that investigated the programming effects of maternal obesity before and during pregnancy on metabolic, cardiovascular, immune, and microbiome perturbations in offspring. Epidemiological studies investigating the effects of maternal obesity on offspring development can be complex due to other copathologies and genetic diversity. Animal studies have provided some insights into the specific mechanisms and pathways involved in programming peripheral disease risk. The effects of maternal obesity during pregnancy on offspring development are often sex specific, with sex-specific changes in placental transport and function suggestive that this organ is likely to play a central role. We believe that this review will assist in facilitating future investigations regarding the underlying mechanisms that link maternal obesity and offspring disease risk in peripheral organs.

Developmental programming of appetite and growth in male rats increases hypothalamic serotonin (5-HT)5A receptor expression and sensitivity

BACKGROUND

Though it is well established that neonatal nutrition plays a major role in lifelong offspring health, the mechanisms underpinning this have not been well defined. Early postnatal accelerated growth resulting from maternal nutritional status is associated with increased appetite and body weight. Likewise, slow growth correlates with decreased appetite and body weight. Food consumption and food-seeking behaviour are directly modulated by central serotonergic (5-hydroxytryptamine, 5-HT) pathways. This study examined the effect of a rat maternal postnatal low protein (PLP) diet on 5-HT receptor mediated food intake in offspring.

METHODS

Microarray analyses, in situ hybridization or laser capture microdissection of the ARC followed by RT-PCR were used to identify genes up- or down-regulated in the arcuate nucleus of the hypothalamus (ARC) of 3-month-old male PLP rats. Third ventricle cannulation was used to identify altered sensitivity to serotonin receptor agonists and antagonists with respect to food intake.

RESULTS

Male PLP offspring consumed less food and had lower growth rates up to 3 months of age compared with Control offspring from dams fed a normal diet. In total, 97 genes were upregulated including the 5-HT5A receptor (5-HT5AR) and 149 downregulated genes in PLP rats compared with Controls. The former obesity medication fenfluramine and the 5-HT receptor agonist 5-Carboxamidotryptamine (5-CT) significantly suppressed food intake in both groups, but the PLP offspring were more sensitive to d-fenfluramine and 5-CT compared with Controls. The effect of 5-CT was antagonized by the 5-HT5AR antagonist SB699551. 5-CT also reduced NPY-induced hyperphagia in both Control and PLP rats but was more effective in PLP offspring.

CONCLUSIONS

Postnatal low protein programming of growth in rats enhances the central effects of serotonin on appetite by increasing hypothalamic 5-HT5AR expression and sensitivity. These findings provide insight into the possible mechanisms through which a maternal low protein diet during lactation programs reduced growth and appetite in offspring.

Cardiometabolic health in offspring of women with PCOS compared to healthy controls: a systematic review and individual participant data meta-analysis

BACKGROUND

Women diagnosed with polycystic ovary syndrome (PCOS) suffer from an unfavorable cardiometabolic risk profile, which is already established by child-bearing age.

OBJECTIVE AND RATIONALE

The aim of this systematic review along with an individual participant data meta-analysis is to evaluate whether cardiometabolic features in the offspring (females and males aged 1–18 years) of women with PCOS (OPCOS) are less favorable compared to the offspring of healthy controls.

SEARCH METHODS

PubMed, Embase and gray literature databases were searched by three authors independently (M.N.G., M.A.W and J.C.) (last updated on 1 February 2018). Relevant key terms such as ‘offspring’ and ‘PCOS’ were combined. Outcomes were age-specific standardized scores of various cardiometabolic parameters: BMI, blood pressure, glucose, insulin, lipid profile and the sum scores of various cardiometabolic features (metabolic sum score). Linear mixed models were used for analyses with standardized beta (β) as outcome.

OUTCOMES

Nine relevant observational studies could be identified, which jointly included 1367 children: OPCOS and controls, originating from the Netherlands, Chile and the USA. After excluding neonates, duplicate records and follow-up screenings, a total of 885 subjects remained. In adjusted analyses, we observed that OPCOS (n = 298) exhibited increased plasma levels of fasting insulin (β = 0.21(95%CI: 0.01–0.41), P = 0.05), insulin-resistance (β = 0.21(95%CI: 0.01–0.42), P = 0.04), triglycerides (β = 0.19(95%CI: 0.02–0.36), P = 0.03) and high-density lipoprotein (HDL)-cholesterol concentrations (β = 0.31(95%CI: 0.08–0.54), P < 0.01), but a reduced birthweight (β = −116(95%CI: −195 to 38), P < 0.01) compared to controls (n = 587). After correction for multiple testing, however, differences in insulin and triglycerides lost their statistical significance. Interaction tests for sex revealed differences between males and females when comparing OPCOS versus controls. A higher 2-hour fasting insulin was observed among female OPCOS versus female controls (estimated difference for females (β_f) = 0.45(95%CI: 0.07 to 0.83)) compared to the estimated difference between males ((β_m) = −0.20(95%CI: −0.58 to 0.19)), with interaction-test: P = 0.03. Low-density lipoprotein–cholesterol differences in OPCOS versus controls were lower among females (β_f = −0.39(95%CI: −0.62 to 0.16)), but comparable between male OPCOS and male controls (β_m = 0.27(95%CI: −0.03 to 0.57)), with interaction-test: P < 0.01. Total cholesterol differences in OPCOS versus controls were also lower in females compared to the difference in male OPCOS and male controls (β_f = −0.31(95%CI: −0.57 to 0.06), β_m = 0.28(95%CI: −0.01 to 0.56), interaction-test: P = 0.01). The difference in HDL-cholesterol among female OPCOS versus controls (β_f = 0.53(95%CI: 0.18–0.88)) was larger compared to the estimated mean difference among OPCOS males and the male controls (β_m = 0.13(95%CI: −0.05−0.31), interaction-test: P < 0.01). Interaction test in metabolic sum score revealed a significant difference between females (OPCOS versus controls) and males (OPCOS versus controls); however, sub analyses performed in both sexes separately did not reveal a difference among females (OPCOS versus controls: β_f = −0.14(95%CI: −1.05 to 0.77)) or males (OPCOS versus controls: β_m = 0.85(95%CI: −0.10 to 1.79)), with P-value < 0.01.

WIDER IMPLICATIONS

We observed subtle signs of altered cardiometabolic health in OPCOS. Therefore, the unfavorable cardiovascular profile of women with PCOS at childbearing age may—next to a genetic predisposition—influence the health of their offspring. Sensitivity analyses revealed that these differences were predominantly observed among female offspring aged between 1 and 18 years. Moreover, studies with minimal risk of bias should elucidate the influence of a PCOS diagnosis in mothers on both sexes during fetal development and subsequently during childhood.

Association between the maternal protein nutrition status during pregnancy and the risk of preterm birth

We aimed to assess protein nutrition status during pregnancy by maternal plasma total protein (MTP) levels in urban pregnant women and to explore the association between the trimester-specific MTP levels and risk of preterm birth (PTB). A prospective design was conducted in 3,382 mother-newborn pairs with the second-trimester maternal MTP information and in 3,478 mother-newborn pairs with the third-trimester MTP information. Multiple Cox proportional hazard regression and multiple linear regression were used to analyse the associations between MTP levels and PTB risk as well as gestational duration, respectively. Nearly all the second-trimester MTP levels were within the clinical reference range, but more than 40% of the third-trimester MTP levels were less than the lower limit of normal. No significant association was found between the second-trimester MTP level and PTB risk. However, the adjusted hazard ratios (HRs) of PTB across increasing quartiles of the third-trimester MTP levels were 1.00 (reference), 0.59 (0.36, 0.95), 0.35 (0.20, 0.60), and 0.32 (0.19, 0.53) (p _{for trend} < 0.001), respectively. Each standard deviations increment of the third-trimester MTP was associated with increase of 0.13 weeks in gestational duration. Moreover, stratified analyses showed that the effects of third-trimester MTP on PTB risk and gestational duration were stronger in pregnant women carrying female offspring than those carrying male offspring (p _{for interaction} < 0.05). The third-trimester MTP level was inversely associated with PTB risk and was positively associated with gestational duration. Improving third-trimester MTP level may be helpful for preventing PTB.

Perinatal exposure to maternal obesity: Lasting cardiometabolic impact on offspring

Evidence from epidemiological, clinical, and animal model studies clearly demonstrates that prenatal and lactational maternal obesity and high-fat diet consumption are associated with cardiometabolic morbidity in offspring. Fetal and offspring sex may be an important effect modifier. Adverse offspring cardiometabolic outcomes observed in the setting of maternal obesity include an increased risk for obesity, features of metabolic syndrome (hypertension, hyperglycemia and insulin resistance, hyperlipidemia, increased adiposity), and non-alcoholic fatty liver disease. This review article synthesizes human and animal data linking maternal obesity and high-fat diet consumption in pregnancy and lactation to adverse cardiometabolic outcomes in offspring. We review key mechanisms underlying skeletal muscle, adipose tissue, pancreatic, liver, and central brain reward programming in obesity-exposed offspring, and how such malprogramming contributes to offspring cardiometabolic morbidity.

Leprdb/+ Dams Protect Wild-type Male Offspring Bone Strength from the Detrimental Effects of a High-Fat Diet

The prevalence of maternal obesity is increasing at an alarming rate and increases the life-long risk of developing cardiometabolic disease in adult offspring. Leptin, an adipokine, is systemically elevated in the obese milieu. We recently showed that maternal hyperleptinemia without obesity improves offspring insulin sensitivity and glucose tolerance while protecting against weight gain on a high-fat, high-sugar (HFD). Here, we investigate the effect of maternal hyperleptinemia on offspring bone by using 2 independent maternal models. First, we compared wild-type (WT) offspring from severely hyperleptinemic Leprdb/+ (DB/+) dams with those from WT dams. In the second model, WT females were implanted with miniosmotic pumps that released either saline (group SAL) or leptin (group LEP; 650ng/hour) and the WT offspring were compared. At 23 weeks of age, a subset of offspring were challenged with a HFD for 8 weeks. When the offspring were 31 weeks of age, bone geometry, strength, and material properties were investigated. The HFD increased trabecular bone volume but decreased both total breaking strength and material strength of femora from the offspring of WT dams. However, male offspring of DB/+ dams were protected from the detrimental effects of a HFD, while offspring of LEP dams were not. Further material analysis revealed a modest decrease in advanced glycation end product accumulation coupled with increased collagen crosslinking in male offspring from DB/+ dams on a HFD. These data suggest that while maternal leptin may protect bone quality from the effects of a HFD, additional factors of the maternal environment controlled by leptin receptor signaling are likely also involved.

Consequences of early life overfeeding for microglia - Perspectives from rodent models

The early life period is crucially important to how the individual develops, and environmental and lifestyle challenges during this time can lead to lasting programming effects on the brain and immune system. In particular, poor diet in early development can lead to long-term negative metabolic and cognitive outcomes, with those who over-eat in early development being at risk of obesity and poor learning and memory throughout their adult lives. Current research has identified a neuroinflammatory component to this metabolic and cognitive programming that can potentially be manipulated to restore a healthy phenotype. Thus, early life over-feeding in a rat model leads to microglial priming and an exacerbated microglial response to immune challenge when the rats reach adulthood. Microglial responses to a learning task are also impaired. To specifically investigate the role of microglia in these programming effects our group has developed a novel transgenic rat with a diphtheria toxin receptor insertion in the promoter region for the Cx3cr1 gene, expressed on microglia and monocytes; allowing us to conditionally ablate microglia throughout the brain. With this model we reveal that microglia have a direct role in regulating feeding behavior and modifying cognition, but are not likely to be the sole mechanism by which early life overfeeding confers lasting neuroimmune and cognitive effects. Additional work implicates changes to the hypothalamic-pituitary-adrenal axis in this. Together these data highlight the importance of dietary choices in early life and the potential for positive interventions targeting the neuroimmune and neuroendocrine stress systems to reverse such programming damage.

Sex-dependent associations of low birth weight and suicidal ideation in adulthood: a community-based cohort study

Low birth weight (LBW; < 2,500 g) has been identified as a risk factor for adverse mental health outcomes over the life span. However, little is known about the association of LBW and suicidal ideation in middle and late adulthood. We investigated N = 8,278 participants of a representative community cohort: 3,849 men (46.5%) and 4,429 women (53.5%) (35-74 years of age). We assessed standardized measures of mental distress, sociodemographics, health behavior, and somatic factors (based on an extensive medical assessment). Controlling for these confounders, we examined the relationship of birth weight and suicidal ideation in logistic regression models. As men and women differ with regard to their susceptibility to suicidal ideation and behavior, we tested sex-dependent effects. LBW was reported by 458 participants (5.5%). In men, LBW was associated with a higher likelihood of reporting suicidal ideation (OR 2.92, 95% CI 1.58-5.12). In women, there was no such relationship. The findings underscore the interrelatedness of the physical and psychological domain, the role of early adversity in suicidal ideation, and they identify a vulnerable group whose numbers are expected to grow. They also indicate other risk factors for suicidal ideation in the community (mental distress, lack of social support, and health risk behavior).

Tobacco smoking during breastfeeding increases the risk of developing metabolic syndrome in adulthood: Lessons from experimental models

Metabolic syndrome (MetS) is characterized by increased abdominal fat, dyslipidemia, diabetes mellitus and hypertension. A high MetS prevalence is strongly associated with obesity. Obesity is a public health problem in which several complex factors have been implicated, including environmental pollutants. For instance, maternal smoking seems to play a role in obesogenesis in childhood. Given the association between endocrine disruptors, obesity and metabolic programming, over the past 10 years, our research group has contributed to studies based on the hypothesis that early exposure to nicotine/tobacco causes offspring to become MetS-prone. The mechanism by which tobacco smoking during breastfeeding induces metabolic dysfunctions is not completely understood; however, increased metabolic programming has been shown in studies that focus on this topic. Here, we reviewed the literature mainly based in light of our latest data from experimental models. Nicotine or tobacco exposure during breastfeeding induces several endocrine dysfunctions in a sex- and tissue-specific manner. This review provides an updated summary regarding the hypothesis that early exposure to nicotine/tobacco causes offspring to become MetS-prone. An understanding of this issue can provide support to prevent long-term disorders, mainly related to the risk of obesity and its comorbidities, in future generations.

Maternal high-fat diet induces long-term obesity with sex-dependent metabolic programming of adipocyte differentiation, hypertrophy and dysfunction in the offspring

Maternal obesity determines obesity and metabolic diseases in the offspring. The white adipose tissue (WAT) orchestrates metabolic pathways, and its dysfunction contributes to metabolic disorders in a sex-dependent manner. Here, we tested if sex differences influence the molecular mechanisms of metabolic programming of WAT in offspring of obese dams. To this end, maternal obesity was induced with high-fat diet (HFD) and the offspring were studied at an early phase [postnatal day 21 (P21)], a late phase (P70) and finally P120. In the early phase we found a sex-independent increase in WAT in offspring of obese dams using magnetic resonance imaging (MRI), which was more pronounced in females than males. While the adipocyte size increased in both sexes, the distribution of WAT differed in males and females. As mechanistic hints, we identified an inflammatory response in females and a senescence-associated reduction in the preadipocyte factor DLK in males. In the late phase, the obese body composition persisted in both sexes, with a partial reversal in females. Moreover, female offspring recovered completely from both the adipocyte hypertrophy and the inflammatory response. These findings were linked to a dysregulation of lipolytic, adipogenic and stemness-related markers as well as AMPKα and Akt signaling. Finally, the sex-dependent metabolic programming persisted with sex-specific differences in adipocyte size until P120. In conclusion, we do not only provide new insights into the molecular mechanisms of sex-dependent metabolic programming of WAT dysfunction, but also highlight the sex-dependent development of low- and high-grade pathogenic obesity.

Stress, Sex, and Sugar: Glucocorticoids and Sex-Steroid Crosstalk in the Sex-Specific Misprogramming of Metabolism

Early-life exposures to environmental insults can misprogram development and increase metabolic disease risk in a sex-dependent manner by mechanisms that remain poorly characterized. Modifiable factors of increasing public health relevance, such as diet, psychological stress, and endocrine-disrupting chemicals, can affect glucocorticoid receptor signaling during gestation and lead to sex-specific postnatal metabolic derangements. Evidence from humans and animal studies indicate that glucocorticoids crosstalk with sex steroids by several mechanisms in multiple tissues and can affect sex-steroid-dependent developmental processes. Nonetheless, glucocorticoid sex-steroid crosstalk has not been considered in the glucocorticoid-induced misprogramming of metabolism. Herein we review what is known about the mechanisms by which glucocorticoids crosstalk with estrogen, androgen, and progestogen action. We propose that glucocorticoid sex-steroid crosstalk is an understudied mechanism of action that requires consideration when examining the developmental misprogramming of metabolism, especially when assessing sex-specific outcomes.

Analysis of structure and gene expression in developing kidneys of male and female rats exposed to low protein diets in utero

A maternal low protein (LP) diet in rodents often results in low nephron endowment and renal pathophysiology in adult life, with outcomes often differing between male and female offspring. Precisely how a maternal LP diet results in low nephron endowment is unknown. We conducted morphological and molecular studies of branching morphogenesis and nephrogenesis to identify mechanisms and timepoints that might give rise to low nephron endowment. Sprague-Dawley rats were fed a normal protein (19.4% protein, NP) or LP (9% protein) diet for 3 weeks prior to mating and throughout gestation. Embryonic day 14.25 (E14.25) kidneys from males and females were either cultured for 2 days after which branching morphogenesis was quantified, or frozen for gene expression analysis. Real-time PCR was used to quantify expression of key nephrogenesis and branching morphogenesis genes at E14.25 and 17.25. At E17.25, nephron number was determined in fixed tissue. There was no effect of either maternal diet or sex on branching morphogenesis. Nephron number at E17.25 was 14% lower in male and female LP offspring than in NP controls. At E14.25 expression levels of genes involved in branching morphogenesis (Gfrα1, Bmp4, Gdnf) and nephrogenesis (Hnf4a, Pax2, Wnt4) were similar in the dietary groups, but significant differences between sexes were identified. At E17.25, expression of Gfrα1, Gdnf, Bmp4, Pax2 and Six2 was lower in LP offspring than NP offspring, in both male and female offspring. These findings provide new insights into how a LP diet leads to low nephron endowment and renal sexual dimorphism.

Placental Metabolomics for Assessment of Sex-specific Differences in Fetal Development During Normal Gestation

The placenta is a metabolically active interfacial organ that plays crucial roles in fetal nutrient delivery, gas exchange and waste removal reflecting dynamic maternal and fetal interactions during gestation. There is growing evidence that the sex of the placenta influences fetal responses to external stimuli in utero, such as changes in maternal nutrition and exposure to environmental stressors. However, the exact biochemical mechanisms associated with sex-specific metabolic adaptations during pregnancy and its link to placental function and fetal development remain poorly understood. Herein, multisegment injection-capillary electrophoresis-mass spectrometry is used as a high throughput metabolomics platform to characterize lyophilized placental tissue (~2 mg dried weight) from C57BL/6J mice fed a standardized diet. Over 130 authentic metabolites were consistently measured from placental extracts when using a nontargeted metabolomics workflow with stringent quality control and robust batch correction. Our work revealed distinct metabolic phenotype differences that exist between male (n = 14) and female (n = 14) placentae collected at embryonic day E18.5. Intracellular metabolites associated with fatty acid oxidation and purine degradation were found to be elevated in females as compared to male placentae (p < 0.05, effect size >0.40), including uric acid, valerylcarnitine, hexanoylcarnitine, and 3-hydroxyhexanolycarnitine. This murine model sheds new insights into sex-specific differences in placental mitochondrial function and protective mechanisms against deleterious oxidative stress that may impact fetal growth and birth outcomes later in life.

Developmental programming of insulin resistance: are androgens the culprits?

Insulin resistance is a common feature of many metabolic disorders. The dramatic rise in the incidence of insulin resistance over the past decade has enhanced focus on its developmental origins. Since various developmental insults ranging from maternal disease, stress, over/undernutrition, and exposure to environmental chemicals can all program the development of insulin resistance, common mechanisms may be involved. This review discusses the possibility that increases in maternal androgens associated with these various insults are key mediators in programming insulin resistance. Additionally, the intermediaries through which androgens misprogram tissue insulin sensitivity, such as changes in inflammatory, oxidative, and lipotoxic states, epigenetic, gut microbiome and insulin, as well as data gaps to be filled are also discussed.

Strength of nonhuman primate studies of developmental programming: review of sample sizes, challenges, and steps for future work

Nonhuman primate (NHP) studies are crucial to biomedical research. NHPs are the species most similar to humans in lifespan, body size, and hormonal profiles. Planning research requires statistical power evaluation, which is difficult to perform when lacking directly relevant preliminary data. This is especially true for NHP developmental programming studies, which are scarce. We review the sample sizes reported, challenges, areas needing further work, and goals of NHP maternal nutritional programming studies. The literature search included 27 keywords, for example, maternal obesity, intrauterine growth restriction, maternal high-fat diet, and maternal nutrient reduction. Only fetal and postnatal offspring studies involving tissue collection or imaging were included. Twenty-eight studies investigated maternal over-nutrition and 33 under-nutrition; 23 involved macaques and 38 baboons. Analysis by sex was performed in 19; minimum group size ranged from 1 to 8 (mean 4.7 ± 0.52, median 4, mode 3) and maximum group size from 3 to 16 (8.3 ± 0.93, 8, 8). Sexes were pooled in 42 studies; minimum group size ranged from 2 to 16 (mean 5.3 ± 0.35, median 6, mode 6) and maximum group size from 4 to 26 (10.2 ± 0.92, 8, 8). A typical study with sex-based analyses had group size minimum 4 and maximum 8 per sex. Among studies with sexes pooled, minimum group size averaged 6 and maximum 8. All studies reported some significant differences between groups. Therefore, studies with group sizes 3-8 can detect significance between groups. To address deficiencies in the literature, goals include increasing age range, more frequently considering sex as a biological variable, expanding topics, replicating studies, exploring intergenerational effects, and examining interventions.

Differential Effects of Post-Weaning Diet and Maternal Obesity on Mouse Liver and Brain Metabolomes

Nutritional changes during developmental windows are of particular concern in offspring metabolic disease. Questions are emerging concerning the role of maternal weight changes before conception, particularly for weight loss, in the development of diet-related disorders. Understanding the physiological pathways affected by the maternal trajectories in the offspring is therefore essential, but a broad overview is still lacking. We recently reported both metabolic and behavioral negative outcomes in offspring born to obese or weight-loss mothers and fed a control of high-fat diet, suggesting long-term modeling of metabolic pathways needing to be further characterized. Using non-targeted LC–HRMS, we investigated the impact of maternal and post-weaning metabolic status on the adult male offspring’s metabolome in three tissues involved in energy homeostasis: liver, hypothalamus and olfactory bulb. We showed that post-weaning diet interfered with the abundance of several metabolites, including 1,5-anhydroglucitol, saccharopine and β-hydroxybutyrate, differential in the three tissues. Moreover, maternal diet had a unique impact on the abundance of two metabolites in the liver. Particularly, anserine abundance, lowered by maternal obesity, was normalized by a preconceptional weight loss, whatever the post-weaning diet. This study is the first to identify a programming long-term effect of maternal preconception obesity on the offspring metabolome.

Maternal Protein Restriction in Rats Alters the Expression of Genes Involved in Mitochondrial Metabolism and Epitranscriptomics in Fetal Hypothalamus

Fetal brain development is closely dependent on maternal nutrition and metabolic status. Maternal protein restriction (PR) is known to be associated with alterations in the structure and function of the hypothalamus, leading to impaired control of energy homeostasis and food intake. The objective of this study was to identify the cellular and molecular systems underlying these effects during fetal development. We combined a global transcriptomic analysis on the fetal hypothalamus from a rat model of maternal PR with in vitro neurosphere culture and cellular analyses. Several genes encoding proteins from the mitochondrial respiratory chain complexes were overexpressed in the PR group and mitochondrial metabolic activity in the fetal hypothalamus was altered. The level of the N6-methyladenosine epitranscriptomic mark was reduced in the PR fetuses, and the expression of several genes involved in the writing/erasing/reading of this mark was indeed altered, as well as genes encoding several RNA-binding proteins. Additionally, we observed a higher number of neuronal-committed progenitors at embryonic day 17 (E17) in the PR fetuses. Together, these data strongly suggest a metabolic adaptation to the amino acid shortage, combined with the post-transcriptional control of protein expression, which might reflect alterations in the control of the timing of neuronal progenitor differentiation.

Olive oil supplementation prevents extracellular matrix deposition and reduces prooxidant markers and apoptosis in the offspring´s heart of diabetic rats

Maternal diabetes induces fetal programming of cardiovascular diseases. Diabetes induced-cardiac fibrosis is a process that may start in utero and may be related to the prooxidant/proinflammatory environment. The aim of this study was to investigate the effect of a maternal diet enriched in olive oil on the levels of components and regulators of the extracellular matrix, on prooxidant markers and on apoptosis rate in the heart of 21-day-old offspring of diabetic rats. Maternal diabetes was induced by neonatal administration of streptozotocin. During pregnancy, diabetic and control rats were fed with diets supplemented or not with 6% olive oil. The heart of the offspring was studied at 21 days of age. We found increased deposition of collagen IV and fibronectin in the offspring´s heart of diabetic rats, which was prevented by the maternal diets enriched in olive oil. Increases in connective tissue growth factor were also prevented by the maternal diets enriched in olive oil. Prooxidant markers as well as apoptosis, which were increased in the heart of the offspring of diabetic rats, were prevented by the maternal olive oil dietary treatment. Our findings identified powerful effects of a maternal diet enriched in olive oil on the prevention of increased extracellular matrix deposition and increased prooxidant markers in the heart of 21-day-old offspring of diabetic rats.

Does cord blood leptin level mediate the association between neonatal body size and postnatal growth? Results from the EDEN mother-child cohort study

Background: Leptin is potentially involved in the correction of early postnatal growth of infants having deviated from their genetic trajectory in utero.Aim: To analyse the potential mediating role of cord blood leptin level in the association between neonatal anthropometry and early postnatal growth in the mother-child EDEN cohort.Subjects and methods: We included term newborns with information on leptin, birth weight and length, and weight and length SD-score changes over the first 2 months. The Baron and Kenny method was used to quantify the mediation contribution of leptin in the association between neonatal anthropometry and postnatal growth, considering several confounders. Analyses were stratified to consider sexual dimorphism.Results: A 1 SD higher birth weight was associated with a lower 2-months weight variation of 0.27 (0.18; 0.36) SD and a 0.16 (0.06; 0.26) SD, in boys and girls, respectively. Leptin explained 20% and 25% of these associations, respectively. Leptin did not mediate the association between birth length and birth-to-2 months length variation.Conclusion: Our results suggest that cord blood leptin may not be involved in the negative association between birth length and postnatal length growth but may play a modest mediating role in early postnatal catch-up or catch-down in weight.

Maternal Obesity Modulates Expression of Satb2 in Hypothalamic VMN of Female Offspring

Maternal obesity during pregnancy is associated with a greater risk of poor health outcomes in offspring, including obesity, metabolic disorders, and anxiety, however the incidence of these diseases differs for males and females. Similarly, animal models of maternal obesity have reported sex differences in offspring, for both metabolic outcomes and anxiety-like behaviors. The ventromedial nucleus of the hypothalamus (VMN) is a brain region known to be involved in the regulation of both metabolism and anxiety, and is well documented to be sexually dimorphic. As the VMN is largely composed of glutamatergic neurons, which are important for its functions in modulating metabolism and anxiety, we hypothesized that maternal obesity may alter the number of glutamatergic neurons in the offspring VMN. We used a mouse model of a maternal high-fat diet (mHFD), to examine mRNA expression of the glutamatergic neuronal marker Satb2 in the mediobasal hypothalamus of control and mHFD offspring at GD17.5. We found sex differences in Satb2 expression, with mHFD-induced upregulation of Satb2 mRNA in the mediobasal hypothalamus of female offspring, compared to controls, but not males. Using immunohistochemistry, we found an increase in the number of SATB2-positive cells in female mHFD offspring VMN, compared to controls, which was localized to the rostral region of the nucleus. These data provide evidence that maternal nutrition during gestation alters the developing VMN, possibly increasing its glutamatergic drive of offspring in a sex-specific manner, which may contribute to sexual dimorphism in offspring health outcomes later in life.

Late-pregnancy uterine artery ligation increases susceptibility to postnatal Western diet-induced fat accumulation in adult female offspring

Stressors during the fetal and postnatal period affect the growth and developmental trajectories of offspring, causing lasting effects on physiologic regulatory systems. Here, we tested whether reduced uterine artery blood flow in late pregnancy would alter body composition in the offspring, and whether feeding offspring a western diet (WD) would aggravate these programming effects. Pregnant rats underwent bilateral uterine artery ligation (BUAL) or sham surgery on gestational day (GD)18 (term = GD22). At weaning, offspring from each group received either a normal diet (ND) or a WD. BUAL surgery increased fetal loss and caused offspring growth restriction, albeit body weights were no longer different at weaning, suggesting postnatal catch-up growth. BUAL did not affect body weight gain, fat accumulation, or plasma lipid profile in adult male offspring. In contrast, while ND-fed females from BUAL group were smaller and leaner than their sham-littermates, WD consumption resulted in excess weight gain, fat accumulation, and visceral adiposity. Moreover, WD increased plasma triglycerides and cholesterol in the BUAL-treated female offspring without any effect on sham littermates. These results demonstrate that reduced uterine artery blood flow during late pregnancy in rodents can impact body composition in the offspring in a sex-dependent manner, and these effects may be exacerbated by postnatal chronic WD consumption.

Excessive early-life cholesterol exposure may have later-life consequences for nonalcoholic fatty liver disease

The in utero and immediate postnatal environments are recognized as critical windows of developmental plasticity where offspring are highly susceptible to changes in the maternal metabolic milieu. Maternal hypercholesterolemia (MHC) is a pathological condition characterized by an exaggerated rise in maternal serum cholesterol during pregnancy which can program metabolic dysfunction in offspring, including dysregulation of hepatic lipid metabolism. Although there is currently no established reference range MHC, a loosely defined cutoff point for total cholesterol >280 mg/dL in the third trimester has been suggested. There are several unanswered questions regarding this condition particularly with regard to how the timing of cholesterol exposure influences hepatic lipid dysfunction and the mechanisms through which these adaptations manifest in adulthood. Gestational hypercholesterolemia increased fetal hepatic lipid concentrations and altered lipid regulatory mRNA and protein content. These early changes in hepatic lipid metabolism are evident in the postweaning environment and persist into adulthood. Further, changes to hepatic epigenetic signatures including microRNA (miR) and DNA methylation are observed in utero, at weaning, and are evident in adult offspring. In conclusion, early exposure to cholesterol during critical developmental periods can predispose offspring to the early development of nonalcoholic fatty liver disease (NAFLD) which is characterized by altered regulatory function beginning in utero and persisting throughout the life cycle.

Birth weight related blood concentrations of the neurotransmission amino acids glutamine plus glutamate, phenylalanine and tyrosine in full-term breastfed infants perinatally

Background The amino acids glutamine plus glutamate, phenylalanine and tyrosine are implicated in neurotransmission. We aimed to evaluate these amino acid blood concentrations in full-term breastfed infants with different birth weight (BW) perinatally. Methods Breastfed full-term infants (n = 6000, males 3000, females 3000) BW 2000-4000 g were divided into four equal groups. Both males and females Groups A, 2000-2500 g, B 2500-3000 g, C 3000-3500 g, D 3500-4000 g. Blood samples on Guthrie cards, were taken on the 3rd day of life and quantified via a liquid chromatography tandem mass spectrometry (LC-MS/MS) method. Results Glutamine plus glutamate mean values were found to be statistically significantly different between males vs. females in all the studied groups. The highest values were determined in both males and females in group D. Statistically significantly higher values of phenylalanine appeared in group D vs. other groups. Tyrosine mean values were calculated to be statistically significantly different in both sexes in group A compared to other groups. Conclusions Differences of glutamine plus glutamate, phenylalanine and tyrosine levels among full-term newborns with different BW are presented for the first time in the literature. Newborns with BW 3000-4000 g are benefited by having higher concentrations of the mentioned neurotransmission related amino acids. Neonatal screening reference values for these amino acids in relation to BW could be established, not only for preterm and low BW infants but also for full-term newborns with BW >3000 g.

Impact of maternal obesity on placental transcriptome and morphology associated with fetal growth restriction in mice

BACKGROUND

In utero exposure to obesity is consistently associated with increased risk of metabolic disease, obesity and cardiovascular dysfunction in later life despite the divergence of birth weight outcomes. The placenta plays a critical role in offspring development and long-term health, as it mediates the crosstalk between the maternal and fetal environments. However, its phenotypic and molecular modifications in the context of maternal obesity associated with fetal growth restriction (FGR) remain poorly understood.

METHODS

Using a mouse model of maternal diet-induced obesity, we investigated changes in the placental transcriptome through RNA sequencing (RNA-seq) and Ingenuity Pathway Analysis (IPA) at embryonic day (E) 19. The most differentially expressed genes (FDR < 0.05) were validated by Quantitative real-time PCR (qPCR) in male and female placentae at E19. The expression of these targets and related genes was also determined by qPCR at E13 to examine whether the observed alterations had an earlier onset at mid-gestation. Structural analyses were performed using immunofluorescent staining against Ki67 and CD31 to investigate phenotypic outcomes at both timepoints.

RESULTS

RNA-seq and IPA analyses revealed differential expression of transcripts and pathway interactions related to placental vascular development and tissue morphology in obese placentae at term, including downregulation of Muc15, Cnn1, and Acta2. Pdgfb, which is implicated in labyrinthine layer development, was downregulated in obese placentae at E13. This was consistent with the morphological evidence of reduced labyrinth zone (LZ) size, as well as lower fetal weight at both timepoints irrespective of offspring sex.

CONCLUSIONS

Maternal obesity results in abnormal placental LZ development and impaired vascularization, which may mediate the observed FGR through reduced transfer of nutrients across the placenta.

Maternal Adiposity is Associated with Fat Mass Accretion in Female but not Male Offspring During the First 2 Years of Life

OBJECTIVE

This study investigated which antenatal and postnatal factors determine offspring adiposity during the first 2 years of life.

METHODS

Participants were mother and child pairs (N = 224). Offspring percent fat mass (%FM) was obtained using quantitative nuclear magnetic resonance at 11 time points between ages 0.5 and 24 months. Independent variables included race, age, gestational weight gain, first-trimester %FM, delivery mode, gestational measures of resting energy expenditure, respiratory exchange ratio, physical activity, serum cytokines and lipids, and dietary intake for the mothers, as well as sex, birth weight and length, breastfeeding duration, and physical activity at age 2 years for the children. Linear mixed models were used to construct the best-fitted models for the entire cohort and for each sex.

RESULTS

Maternal %FM (P = 0.006), high-density lipoprotein (HDL) (P < 0.001), and breastfeeding duration (P = 0.023) were positively associated with female offspring adiposity, whereas maternal dietary fiber intake (P = 0.016) had a negative association. Birth weight (P = 0.004), maternal HDL (P = 0.013), and breastfeeding duration (P = 0.015) were all positively associated with male offspring adiposity.

CONCLUSIONS

Antenatal and postnatal factors differentially impact male and female offspring adiposity during the first 2 years of life.

Prenatal stress and later metabolic consequences: Systematic review and meta-analysis in rodents

BACKGROUND

Numerous rodent studies have evaluated the effects of maternal stress (MS) on later in life susceptibility to Metabolic Syndrome (MetS) intermediate phenotypes with varying results. The aim of this study was to quantitatively synthesize the available data on the effects of MS on offspring obesity, estimated indirectly by body mass (BM), body fat (BF) and plasma leptin; systolic blood pressure (SBP); plasma glucose (and insulin) and blood lipid concentrations.

METHODS

Literature was screened and summary estimates of the effect of MS outcomes were calculated by using random-effects models. Data on the effects of exogenous corticosteroid administration (or inhibition of 11β-HSD2) during pregnancy in rodents was analysed separately to characterize the direct phenotypic effects of prenatal corticosteroid excess (PCE).

RESULTS

We conducted 14 separate meta-analyses and synthesized relevant data on outcomes scarcely reported in literature. Both MS and PCE were associated with low birth weight without rapid catch-up growth resulting in decreased body mass later in life. Our analysis also revealed significant and contradictory effects on offspring adiposity. Little evidence was found for effects on glucose metabolism and blood lipids. We identified increased SBP in offspring exposed to PCE; however, there is not enough data to draw any conclusion about effects of MS on SBP.

CONCLUSIONS

Neonatal weight proved to be decreased in offspring prenatally exposed to stress or corticosteroids, but laboratory rodents in the absence of a challenging environment did not show catch-up growth. The available evidence is inconclusive regarding the effect on adiposity revealing clear methodological and knowledge gaps. This meta-analysis also confirmed a significant positive association between PCE and SBP. Nevertheless, additional studies should address the association with MS.

Sex differences in metabolic regulation and diabetes susceptibility

Gender and biological sex impact the pathogenesis of numerous diseases, including metabolic disorders such as diabetes. In most parts of the world, diabetes is more prevalent in men than in women, especially in middle-aged populations. In line with this, considering almost all animal models, males are more likely to develop obesity, insulin resistance and hyperglycaemia than females in response to nutritional challenges. As summarised in this review, it is now obvious that many aspects of energy balance and glucose metabolism are regulated differently in males and females and influence their predisposition to type 2 diabetes. During their reproductive life, women exhibit specificities in energy partitioning as compared with men, with carbohydrate and lipid utilisation as fuel sources that favour energy storage in subcutaneous adipose tissues and preserve them from visceral and ectopic fat accumulation. Insulin sensitivity is higher in women, who are also characterised by higher capacities for insulin secretion and incretin responses than men; although, these sex advantages all disappear when glucose tolerance deteriorates towards diabetes. Clinical and experimental observations evidence the protective actions of endogenous oestrogens, mainly through oestrogen receptor α activation in various tissues, including the brain, the liver, skeletal muscle, adipose tissue and pancreatic beta cells. However, beside sex steroids, underlying mechanisms need to be further investigated, especially the role of sex chromosomes, fetal/neonatal programming and epigenetic modifications. On the path to precision medicine, further deciphering sex-specific traits in energy balance and glucose homeostasis is indeed a priority topic to optimise individual approaches in type 2 diabetes prevention and treatment.

Sexually dimorphic metabolic responses to exposure of a high fat diet during pregnancy, lactation and early adulthood in Gipr-/- mice

Obesity has a multifactorial origin. It is known that alterations of the intra uterine milieu induce developmental programming effects leading to metabolic diseases in offspring. Obesity is diminished in mice lacking the glucose-dependent insulinotropic polypeptide receptor (Gipr^-/-) when exposed to a high fat diet (HFD). We investigated whether Gipr^-/- mice are still protected from obesity when additionally exposure to a HFD during pregnancy and lactation occurs. Male and female wild type (WT) and Gipr^-/- offspring received either a control/ low fat diet or HFD during pregnancy and lactation and were then either left on this diet or placed on the opposite diet after weaning until 24 weeks of life. Female WT mice showed increased body weight and adiposity when exposed to a HFD during pregnancy and lactation and post-weaning compared to female WT that received the HFD after weaning only. This exacerbated effect of a HFD during pregnancy and lactation was abolished in female Gipr^-/- mice. Male Gipr^-/- mice were protected from obesity to a much lesser extent. Male Gipr^-/- mice exposed to a HFD during pregnancy and lactation and after weaning exhibited significantly increased fed serum glucose compared to Gipr^-/- mice exposed to a HFD after weaning only. In female Gipr^-/- mice no differences in fed blood glucose were observed between these groups. Our data indicate that female Gipr^-/- mice are more protected from obesity. This protection is preserved in female Gipr^-/- mice when additional deleterious effects of a HFD occur during fetal development.

An examination of sex differences in associations between cord blood adipokines and childhood adiposity

BACKGROUND

Though the physiological roles of adipokines in metabolism, insulin resistance and satiety are clear, literature regarding associations between cord blood adipokine levels and childhood adiposity is equivocal.

OBJECTIVES

To determine whether cord blood levels of leptin and adiponectin are associated with adiposity in children 2 to 5 years of age, and whether such associations are modified by sex.

METHODS

Leptin and adiponectin levels were measured in cord blood and anthropometric measures were completed on 550 children enrolled in the Maternal-Infant Research on Environmental Chemicals Child Development Plus study (MIREC-CD Plus). We used multivariable linear and Poisson regression models to determine associations between cord blood adipokine levels and child body mass index (BMI), triceps and subscapular skinfold thickness and risk of overweight/obesity and to assess effect modification by child sex.

RESULTS

Cord blood adiponectin was significantly associated with modest increases in BMI and the sum of triceps and subscapular skinfold z-scores in boys but not girls. A doubling of adiponectin levels was associated with a 30% increased risk of overweight/obesity in boys (RR = 1.30; 95% CI: 1.02, 1.64). Leptin was not associated with anthropometric measures in either sex.

CONCLUSIONS

The observed associations between adiponectin and adiposity in boys were statistically significant, of moderate magnitude, and underscore the value of considering sex-specific patterns.

A toolbox for the longitudinal assessment of healthspan in aging mice

The number of people aged over 65 is expected to double in the next 30 years. For many, living longer will mean spending more years with the burdens of chronic diseases such as Alzheimer's disease, cardiovascular disease, and diabetes. Although researchers have made rapid progress in developing geroprotective interventions that target mechanisms of aging and delay or prevent the onset of multiple concurrent age-related diseases, a lack of standardized techniques to assess healthspan in preclinical murine studies has resulted in reduced reproducibility and slow progress. To overcome this, major centers in Europe and the United States skilled in healthspan analysis came together to agree on a toolbox of techniques that can be used to consistently assess the healthspan of mice. Here, we describe the agreed toolbox, which contains protocols for echocardiography, novel object recognition, grip strength, rotarod, glucose tolerance test (GTT) and insulin tolerance test (ITT), body composition, and energy expenditure. The protocols can be performed longitudinally in the same mouse over a period of 4-6 weeks to test how candidate geroprotectors affect cardiac, cognitive, neuromuscular, and metabolic health.

Prepregnancy obesity is associated with lower psychomotor development scores in boys at age 3 in a low-income, minority birth cohort

Whether maternal obesity and gestational weight gain (GWG) are associated with early-childhood development in low-income, urban, minority populations, and whether effects differ by child sex remain unknown. This study examined the impact of prepregnancy BMI and GWG on early childhood neurodevelopment in the Columbia Center for Children's Environmental Health Mothers and Newborns study. Maternal prepregnancy weight was obtained by self-report, and GWG was assessed from participant medical charts. At child age 3 years, the Psychomotor Development Index (PDI) and Mental Development Index (MDI) of the Bayley Scales of Infant Intelligence were completed. Sex-stratified linear regression models assessed associations between prepregnancy BMI and pregnancy weight gain z-scores with child PDI and MDI scores, adjusting for covariates. Of 382 women, 48.2% were normal weight before pregnancy, 24.1% overweight, 23.0% obese, and 4.7% underweight. At 3 years, mean scores on the PDI and MDI were higher among girls compared to boys (PDI: 102.3 vs. 97.2, P = 0.0002; MDI: 92.8 vs. 88.3, P = 0.0001). In covariate-adjusted models, maternal obesity was markedly associated with lower PDI scores in boys [b = -7.81, 95% CI: (-13.08, -2.55), P = 0.004], but not girls. Maternal BMI was not associated with MDI in girls or boys, and GWG was not associated with PDI or MDI among either sex (all-P > 0.05). We found that prepregnancy obesity was associated with lower PDI scores at 3 years in boys, but not girls. The mechanisms underlying this sex-specific association remain unclear, but due to elevated obesity exposure in urban populations, further investigation is warranted.

Epigenetics: Linking Early Postnatal Nutrition to Obesity Programming?

Despite constant research and public policy efforts, the obesity epidemic continues to be a major public health threat, and new approaches are urgently needed. It has been shown that nutrient imbalance in early life, from conception to infancy, influences later obesity risk, suggesting that obesity could result from "developmental programming". In this review, we evaluate the possibility that early postnatal nutrition programs obesity risk via epigenetic mechanisms, especially DNA methylation, focusing on four main topics: (1) the dynamics of epigenetic processes in key metabolic organs during the early postnatal period; (2) the epigenetic effects of alterations in early postnatal nutrition in animal models or breastfeeding in humans; (3) current limitations and remaining outstanding questions in the field of epigenetic programming; (4) candidate pathways by which early postnatal nutrition could epigenetically program adult body weight set point. A particular focus will be given to the potential roles of breast milk fatty acids, neonatal metabolic and hormonal milieu, and gut microbiota. Understanding the mechanisms by which early postnatal nutrition can promote lifelong metabolic modifications is essential to design adequate recommendations and interventions to "de-program" the obesity epidemic.

Programming effects of maternal and gestational obesity on offspring metabolism and metabolic inflammation

With the increasing prevalence of obesity in women of reproductive age there is a need to understand the ramifications of this on offspring. The purpose of this study is to investigate the programming effects of maternal obesity during preconception and the preconception/gestational period on adiposity and adipose tissue inflammation in offspring using an animal model. Adult female C57Bl/6J mice were assigned either normal diet, high fat diet (HFD) prior to pregnancy, or HFD prior to and through pregnancy. Some offspring were maintained on normal diet while others started HFD later in life. Offspring were assessed for body composition and metabolic responses. Lipid storing tissues were evaluated for expansion and inflammation. Male offspring from the preconception group had the greatest weight gain, most subcutaneous adipose tissue, and largest liver mass when introduced to postnatal HFD. Male offspring of the preconception/gestation group had worsened glucose tolerance and an increase in resident (CD11c⁻) adipose tissue macrophages (ATMs) when exposed to postnatal HFD. Female offspring had no significant difference in any parameter between the diet treatment groups. In conclusion, this study demonstrates that prenatal and pregnancy windows have independent programming effects on offspring. Preconception exposure affects body composition and adiposity while gestation exposure affects metabolism and tissue immune cell phenotypes.

A Narrative Review of Placental Contribution to Adverse Pregnancy Outcomes in Women With Polycystic Ovary Syndrome

CONTEXT

Polycystic ovary syndrome (PCOS) is the most common endocrinopathy of reproductive-aged women. In pregnancy, women with PCOS experience increased risk of miscarriage, gestational diabetes, preeclampsia, and extremes of fetal birth weight, and their offspring are predisposed to reproductive and cardiometabolic dysfunction in adulthood. Pregnancy complications, adverse fetal outcomes, and developmental programming of long-term health risks are known to have placental origins. These findings highlight the plausibility of placental compromise in pregnancies of women with PCOS.

EVIDENCE SYNTHESIS

A comprehensive PubMed search was performed using terms "polycystic ovary syndrome," "placenta," "developmental programming," "hyperandrogenism," "androgen excess," "insulin resistance," "hyperinsulinemia," "pregnancy," and "pregnancy complications" in both human and animal experimental models.

CONCLUSIONS

There is limited human placental research specific to pregnancy of women with PCOS. Gestational androgen excess and insulin resistance are two clinical hallmarks of PCOS that may contribute to placental dysfunction and underlie the higher rates of maternal-fetal complications observed in pregnancies of women with PCOS. Additional research is needed to prevent adverse maternal and developmental outcomes in women with PCOS and their offspring.

Large-for-gestational age is male-gender dependent in artificial frozen embryo transfers cycles: a cohort study of 1295 singleton live births

RESEARCH QUESTION

What is the effect of frozen embryo transfer (FET) on infant birth weight outcomes and which variables predic large-for-gestational age (LGA) infants.

DESIGN

In a large cohort study, the birth weight of 1295 singleton live births from blastocyst freeze-all-IVF treatments carried out between February 2015 and February 2017 at a single IVF centre were analysed. All embryo transfers were vitrified-warmed blastocyst transfers in artificial FET cycles, with patients having one (n = 864) or two (n = 431) blastocysts transferred. All live births were from ultrasound confirmed single fetal heart pregnancies.

RESULTS

The mean gestational age at delivery was 38.2 (±1.7) weeks, with a 1.11 : 1 female to male ratio for infants delivered. The small and large-for-gestational age rates were 5.02 and 13.28%, with 81.7% of infants appropriate for gestational age. In a multiple logistic regression analysis, the independent variables selected in the model to predict having an LGA infant were maternal parity, infant gender and maternal body mass index (BMI). The risk for LGA at term was significantly higher for male infants when adjusting for maternal parity and BMI (2.8 OR 1.805 to 4.450; P < 0.001).

CONCLUSION

The present study showed that fetal growth of artificial cycle FET pregnancies resulted in an 13.28% LGA infant rate that was mostly male gender dependent.

The impact of exposure to cafeteria diet during pregnancy or lactation on offspring growth and adiposity before weaning

Exposure to maternal obesity during early-life can have adverse consequences for offspring growth and adiposity. We aimed to assess the relative contributions of exposure to maternal obesity, induced by a highly varied cafeteria diet, during pregnancy and lactation on these measures in rat offspring prior to weaning. Female Wistar rats were fed either a control (C) or cafeteria diet (O) for 8 weeks before mating, throughout pregnancy and lactation. Offspring were cross-fostered at birth to a dam on the same (CC,OO) or alternate diet prior to birth (CO,OC). Feeding a cafeteria diet based on 40 different foods, was associated with a sustained period of elevated energy intake before birth and during lactation (up to 1.7-fold), through increased sugar, total fat and saturated fat intake, and lower protein consumption. Cafeteria fed dams sustained greater weight than animals fed a control chow diet and greater perirenal adiposity by the end of lactation. Exposure to obesity during pregnancy was associated with lower offspring birth weight and body weight in early-postnatal life. In contrast, exposure during lactation alone reduced offspring weight but increased adiposity in male CO offspring before weaning. This research highlights that exposure to maternal obesity during lactation alone can programme adiposity in a sex specific manner.

Sex differences in the burden of type 2 diabetes and cardiovascular risk across the life course

By 2017 estimates, diabetes mellitus affects 425 million people globally; approximately 90-95% of these have type 2 diabetes. This narrative review highlights two domains of sex differences related to the burden of type 2 diabetes across the life span: sex differences in the prevalence and incidence of type 2 diabetes, and sex differences in the cardiovascular burden conferred by type 2 diabetes. In the presence of type 2 diabetes, the difference in the absolute rates of cardiovascular disease (CVD) between men and women lessens, albeit remaining higher in men. Large-scale observational studies suggest that type 2 diabetes confers 25-50% greater excess risk of incident CVD in women compared with men. Physiological and behavioural mechanisms that may underpin both the observed sex differences in the prevalence of type 2 diabetes and the associated cardiovascular burden are discussed in this review. Gender differences in social behavioural norms and disparities in provider-level treatment patterns are also highlighted, but not described in detail. We conclude by discussing research gaps in this area that are worthy of further investigation.

Factors associated with stillbirth in women with diabetes

AIMS/HYPOTHESIS

Stillbirth risk is increased in pregnancy complicated by diabetes. Fear of stillbirth has major influence on obstetric management, particularly timing of delivery. We analysed population-level data from Scotland to describe timing of stillbirths in women with diabetes and associated risk factors.

METHODS

A retrospective cohort of singleton deliveries to mothers with type 1 (n = 3778) and type 2 diabetes (n = 1614) from 1 April 1998 to 30 June 2016 was analysed using linked routine care datasets. Maternal and fetal characteristics, HbA_1c data and delivery timing were compared between stillborn and liveborn groups.

RESULTS

Stillbirth rates were 16.1 (95% CI 12.4, 20.8) and 22.9 (95% CI 16.4, 31.8) per 1000 births in women with type 1 (n = 61) and type 2 diabetes (n = 37), respectively. In women with type 1 diabetes, higher HbA_1c before pregnancy (OR 1.03 [95% CI 1.01, 1.04]; p = 0.0003) and in later pregnancy (OR 1.06 [95% CI 1.04, 1.08]; p < 0.0001) were associated with stillbirth, while in women with type 2 diabetes, higher maternal BMI (OR 1.07 [95% CI 1.01, 1.14]; p = 0.02) and pre-pregnancy HbA_1c (OR 1.02 [95% CI 1.00, 1.04]; p = 0.016) were associated with stillbirth. Risk was highest in infants with birthweights <10th centile (sixfold higher born to women with type 1 diabetes [n = 5 stillbirths, 67 livebirths]; threefold higher for women with type 2 diabetes [n = 4 stillbirths, 78 livebirths]) compared with those in the 10th-90th centile (n = 20 stillbirths, 1685 livebirths). Risk was twofold higher in infants with birthweights >95th centile born to women with type 2 diabetes (n = 15 stillbirths, 402 livebirths). A high proportion of stillborn infants were male among mothers with type 2 diabetes (81.1% vs 50.5% livebirths, p = 0.0002). A third of stillbirths occurred at term, with highest rates in the 38th week (7.0 [95% CI 3.7, 12.9] per 1000 ongoing pregnancies) among mothers with type 1 diabetes and in the 39th week (9.3 [95% CI 2.4, 29.2]) for type 2 diabetes.

CONCLUSIONS/INTERPRETATION

Maternal blood glucose levels and BMI are important modifiable risk factors for stillbirth in diabetes. Babies at extremes of weight centiles are at most risk. Many stillbirths occur at term and could potentially be prevented by change in routine care and delivery policies.