Maternal Obesity and the Fetal Origins of the Metabolic Syndrome

Consistent cord blood DNA methylation signatures of gestational age between South Asian and white European cohorts

BACKGROUND

Epigenetic modifications, particularly DNA methylation (DNAm) in cord blood, are an important biological marker of how external exposures during gestation can influence the in-utero environment and subsequent offspring development. Despite the recognized importance of DNAm during gestation, comparative studies to determine the consistency of these epigenetic signals across different ethnic groups are largely absent. To address this gap, we first performed epigenome-wide association studies (EWAS) of gestational age (GA) using newborn cord blood DNAm comparatively in a white European (n = 342) and a South Asian (n = 490) birth cohort living in Canada. Then, we capitalized on established cord blood epigenetic GA clocks to examine the associations between maternal exposures, offspring characteristics and epigenetic GA, as well as GA acceleration, defined as the residual difference between epigenetic and chronological GA at birth.

RESULTS

Individual EWASs confirmed 1,211 and 1,543 differentially methylated CpGs previously reported to be associated with GA, in white European and South Asian cohorts, respectively, with a similar distribution of effects. We confirmed that Bohlin's cord blood GA clock was robustly correlated with GA in white Europeans (r = 0.71; p = 6.0 × 10-54) and South Asians (r = 0.66; p = 6.9 × 10-64). In both cohorts, Bohlin's clock was positively associated with newborn weight and length and negatively associated with parity, newborn female sex, and gestational diabetes. Exclusive to South Asians, the GA clock was positively associated with the newborn ponderal index, while pre-pregnancy weight and gestational weight gain were strongly predictive of increased epigenetic GA in white Europeans. Important predictors of GA acceleration included gestational diabetes mellitus, newborn sex, and parity in both cohorts.

CONCLUSIONS

These results demonstrate the consistent DNAm signatures of GA and the utility of Bohlin's GA clock across the two populations. Although the overall pattern of DNAm is similar, its connections with the mother's environment and the baby's anthropometrics can differ between the two groups. Further research is needed to understand these unique relationships.

Dexamethasone exposure during pregnancy triggers metabolic syndrome in offspring via epigenetic alteration of IGF1

BACKGROUND

Previous research has reported that prenatal exposure to dexamethasone (PDE) results in organ dysplasia and increased disease susceptibility in offspring. This study aimed to investigate the epigenetic mechanism of metabolic syndrome induced by PDE in offspring.

METHODS

Pregnant Wistar rats were administered dexamethasone, and their offspring's serum and liver tissues were analyzed. The hepatocyte differentiation model was established to unveil the molecular mechanism. Neonatal cord blood samples were collected to validate the phenomenon and mechanism.

RESULTS

The findings demonstrated that PDE leads to insulin resistance and typical metabolic syndrome traits in adult offspring rats, which originated from fetal liver dysplasia. Additionally, PDE reduced serum corticosterone level and inhibited hepatic insulin-like growth factor 1 (IGF1) signaling in fetal rats. It further revealed that liver dysplasia and functional impairment induced by PDE persist after birth, driven by the continuous downregulation of serum corticosterone and hepatic IGF1 signaling. Both in vitro and in vivo experiments confirmed that low endogenous corticosterone reduces the histone 3 lysine 9 acetylation (H3K27ac) level of IGF1 and its expression by blocking glucocorticoid receptor α, special protein 1, and P300 into the nucleus, resulting in hepatocyte differentiation inhibition and liver dysplasia. Intriguingly, neonatal cord blood samples validated the link between reduced liver function in neonates induced by PDE and decreased serum cortisol and IGF1 levels.

CONCLUSIONS

This study demonstrated that low endogenous glucocorticoid level under PDE lead to liver dysplasia by downregulating the H3K27ac level of IGF1 and its expression, ultimately contributing to metabolic syndrome in adult offspring.

Associations Between Maternal Lipid Blood Levels at the 13th Week of Pregnancy and Offspring's Adiposity at Age 11-12 Years

CONTEXT

There is increasing evidence that intrauterine lipid metabolism influences the adiposity of the newborn and the first years thereafter. It remains unclear if these effects persist when these children grow older.

OBJECTIVE

This study examined the associations between maternal lipid blood levels during the 13th week of pregnancy and an offspring's adiposity, measured at age 11-12, and if these associations were moderated by the child's sex.

METHODS

Data were obtained from a community-based birth cohort, the Amsterdam Born Children and their Development (ABCD) study. At a median of 13 weeks' gestation, nonfasting blood samples of triglycerides (TGs), total cholesterol (TC), free fatty acids (FFAs), and apolipoprotein B/apolipoprotein A1 ratio (ApoB/ApoA1) were measured. An offspring's body mass index (BMI), subcutaneous fat (SCF), waist-to-height-ratio (WHtR), and fat percentage (fat%) were measured at age 11-12. Mothers with at-term born children were included (n = 1853). Multivariable linear regression analyses were performed to assess the associations between maternal lipids and each offspring's adiposity outcome separately. Sex differences were additionally evaluated.

RESULTS

TGs, TC, ApoB/ApoA1, and FFAs were significantly positively associated with BMI, WHtR, and fat% (adjusted for gestational age at blood sampling, child's age, sex, and sexual maturation). After additional adjustments for potential confounders and covariates, only TGs remained significantly associated with WHtR (0.45, 95% CI -0.007; 0.91). There were no associations between maternal lipids and SCF and no clear sex-specific results were found.

CONCLUSION

Overall, our results do not strongly support that maternal lipid profile during the 13th week of pregnancy has programming effects on adiposity in preadolescence.

MIR146A and ADIPOQ genetic variants are associated with birth weight in relation to gestational age: a cohort study

PURPOSE

To evaluate the genetic variants related to polycystic ovary syndrome (PCOS) and its metabolic complications in girls born small for gestational age (SGA).

DESIGN

Retrospective birth cohort study.

MATERIALS AND METHODS

We evaluated 66 women of reproductive age born at term (37-42 weeks of gestational age) according to the birth weight in relation to gestational age: 26 SGA and 40 AGA (Adequate for gestational age). Anthropometric and biochemical characteristics were measured, as well as the PCOS prevalence. We analyzed 48 single nucleotide polymorphisms (SNPs) previously associated with PCOS and its comorbidities using TaqMan Low-Density Array (TLDA). miRNet and STRING databases were used to predict target and disease networks.

RESULTS

Anthropometric and biochemical characteristics did not differ between the SGA and AGA groups, as well as insulin resistance and PCOS prevalence. Two SNPs were not in Hardy-Weinberg equilibrium, the rs2910164 (MIR146A C > G) and rs182052 (ADIPOQ G > A). The rs2910164 minor allele frequency (MAF) was increased in SGA (OR, 2.77; 95%; CI, 1.22-6.29), while the rs182052 was increased AGA (OR, 0.34; 95%; CI, 0.13 - 0.88). The alleles related to reduced miRNA-146a (C) and ADIPOQ (A) activity showed increased frequency in SGA. The mature miR-146a targets 319 genes, been the CXCR4, TMEM167A and IF144L common targets and contributes to PCOS. The ADIPOQ main protein interactions were ERP44, PPARGCIA and CDH13.

CONCLUSIONS

The miR-146a (rs2910164) and ADIPOQ (rs182052) allelic variants are related to birth weight in SGA and may predict health-related outcomes, such as PCOS and obesity risk.

Burden of Early Life Obesity and Its Relationship with Protein Intake in Infancy: The Middle East Expert Consensus

Adequate nutrition in early life is proposed to shape a child's future health by launching the growth trajectory in the proper direction, which helps to avoid negative metabolic programming effects. Protein intake during infancy and early childhood is of great importance, as it plays a key role in infant metabolic programming and the future risk of obesity. Breastfeeding provides the best nutrition in early life, with many benefits tailored for the baby, including the appropriate quantity and quality of proteins. Considering the high prevalence of childhood, and subsequent adult, obesity in the region, a virtual Middle East expert consensus meeting was held to discuss an effective approach for managing childhood obesity. Leading pediatric experts from Bahrain, Egypt, Kuwait, Oman, Qatar, Saudi Arabia, and the United Arab Emirates participated in the meeting. The experts discussed, debated, and agreed on certain directions, including the importance of educating parents, endorsing breastfeeding, and ensuring optimum quantity and quality intake of proteins in early life. This expert consensus may serve as the starting point for healthcare professionals in the region who are interested in shaping a healthy future for the generations to come.

Supplemental Berberine in a High-Fat Diet Reduces Adiposity and Cardiac Dysfunction in Offspring of Mouse Dams with Gestational Diabetes Mellitus

BACKGROUND

There are few evidence-based strategies to attenuate the risk of metabolic syndrome in offspring exposed to gestational diabetes mellitus (GDM). Berberine (BBR) is an isoquinoline alkaloid extracted from Chinese herbs and exhibits glucose lowering properties.

OBJECTIVES

We hypothesized that dietary BBR would improve health outcomes in the mouse offspring of GDM dams.

METHODS

Wild-type C57BL/6 female mice were fed either a Lean-inducing low-fat diet (L-LF,10% kcal fat, 35% kcal sucrose) or a GDM-inducing high-fat diet (GDM-HF, 45% kcal fat, 17.5% sucrose) for 6 wk prior to breeding with wild-type C57BL/6 male mice throughout pregnancy and the suckling period. The resulting Lean and GDM-exposed male and female offspring were randomly assigned an LF (10% kcal fat, 35% kcal sucrose), HF (45% kcal fat, 17.5% sucrose), or high-fat berberine (HFB) (45% kcal fat, 17.5% sucrose diet) containing BBR (160 mg/kg/d, HFB) at weaning for 12 wk. The main outcome was to evaluate the effects of BBR on obesity, pancreatic islet function, and cardiac contractility in GDM-exposed HF-fed offspring. Significance between measurements was determined using a 2 (gestational exposure) × 3 (diet) factorial design by a 2- way ANOVA using Tukey post-hoc analysis.

RESULTS

In the GDM-HF group, body weights were significantly increased (16%) compared with those in baseline (L-LF) animals (P < 0.05). Compared with the L-LF animals, the GDM-HF group had a reduction in pancreatic insulin glucose-stimulated insulin secretion (74%) and increased cardiac isovolumetric contraction time (IVCT; ∼150%) (P < 0.05). Compared with GDM-HF animals, the GDM-HFB group with the dietary addition of BBR had significantly reduced body weight (16%), increased glucose-stimulated insulin secretion from pancreatic islets (254%), and reduced systolic heart function (46% IVCT) (P < 0.05).

CONCLUSIONS

In a mouse model of GDM, dietary BBR treatment provided protection from obesity and the development of pancreatic islet and cardiac dysfunction.

The Weight of Racial Discrimination: Examining the Association Between Racial Discrimination and Change in Adiposity Among Emerging Adult Women Enrolled in a Behavioral Weight Loss Program

BACKGROUND

Non-Hispanic Black (NHB) emerging adult (EA) women are at disproportionate risk for obesity but experience limited benefit from behavioral weight loss (BWL) programs. Race-related stress could play a role; the goal of this study was to examine the association between racial discrimination (RD) and early (3 months) changes in adiposity, and to explore potential protective factors, among EA in an adapted BWL program.

METHODS

This is an ancillary study of non-Hispanic White (NHW) and NHB EA women enrolled in an adapted BWL trial (N = 49; 55.1% NHB; Age 21.2 (2.1); BMI = 33.0 + 4.3 kg/m²). At baseline, group- and personal-level RD (RD-group and RD-personal), racial identity (NHB women only), vigilant coping, and social support were assessed via validated questionnaires. Weight and waist circumference were measured objectively at 0 and 3 months.

RESULTS

NHW women manifested greater reductions in waist circumference relative to NHB women (p = .004). RD-personal did not predict change in waist circumference at 3 months (p = .402); however, the association between RD-group and change in waist circumference was statistically significant (p = .015), such that reporting greater group-level discrimination predicted a smaller decrease in waist circumference; the model explained 22% of the variance. Social support and vigilant coping were not statistically significant in the model. Among NHB women only, higher racial identity-centrality predicted greater reduction in waist circumference (p = .019).

CONCLUSION

Findings suggest racial discrimination could contribute to greater cardiometabolic risk during this developmental period. Future research should examine how experiences of racial discrimination unfold in the daily lives of NHB women to inform mechanistic interventions to enhance health and well-being.

TRIAL REGISTRATION

NCT02736981. Low Intensity Weight Loss for Young Adults.

The Impact of Maternal Body Composition and Dietary Fat Consumption upon Placental Lipid Processing and Offspring Metabolic Health

The proportion of women of reproductive age who are overweight or obese is increasing globally. Gestational obesity is strongly associated in both human studies and animal models with early-onset development of adult-associated metabolic diseases including metabolic syndrome in the exposed offspring. However, animal model studies have suggested that gestational diet in obese pregnancies is an independent but underappreciated mediator of offspring risk for later life metabolic disease, and human diet consumption data have highlighted that many women do not follow nutritional guidelines prior to and during pregnancy. Thus, this review will highlight how maternal diet independent from maternal body composition impacts the risk for later-life metabolic disease in obesity-exposed offspring. A poor maternal diet, in combination with the obese metabolic state, are understood to facilitate pathological in utero programming, specifically through changes in lipid handling processes in the villous trophoblast layer of the placenta that promote an environment associated with the development of metabolic disease in the offspring. This review will additionally highlight how maternal obesity modulates villous trophoblast lipid processing functions including fatty acid transport, esterification and beta-oxidation. Further, this review will discuss how altering maternal gestational diet may ameliorate these functional changes in lipid metabolic processes in the obese placenta.

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.

Placental Adaptive Changes to Protect Function and Decrease Oxidative Damage in Metabolically Healthy Maternal Obesity

Pregnancy-related disorders, including preeclampsia and gestational diabetes, are characterized by the presence of an adverse intrauterine milieu that may ultimately result in oxidative and nitrosative stress. This scenario may trigger uncontrolled production of reactive oxygen species (ROS) such as superoxide anion (O^●−) and reactive nitrogen species (RNS) such as nitric oxide (NO), along with an inactivation of antioxidant systems, which are associated with the occurrence of relevant changes in placental function through recognized redox post-translational modifications in key proteins. The general objective of this study was to assess the impact of a maternal obesogenic enviroment on the regulation of the placental nitroso-redox balance at the end of pregnancy. We measured oxidative damage markers—thiobarbituric acid-reacting substances (TBARS) and carbonyl groups (C=O) levels; nitrosative stress markers—inducible nitric oxide synthase, nitrosothiol groups, and nitrotyrosine residues levels; and the antioxidant biomarkers—catalase and superoxide dismutase (SOD) activity and expression, and total antioxidant capacity (TAC), in full-term placental villous from both pre-pregnancy normal weight and obese women, and with absence of metabolic complications throughout gestation. The results showed a decrease in C=O and TBARS levels in obese pregnancies. Although total SOD and catalase concentrations were shown to be increased, both activities were significantly downregulated in obese pregnancies, along with total antioxidant capacity. Inducible nitric oxide sintase levels were increased in the obese group compared to the lean group, accompanied by an increase in nitrotyrosine residues levels and lower levels of nitrosothiol groups in proteins such as ERK1/2. These findings reveal a reduction in oxidative damage, accompanied by a decline in antioxidant response, and an increase via NO-mediated nitrative stress in placental tissue from metabolically healthy pregnancies with obesity. All this plausibly points to a placental adaptation of the affected antioxidant response towards a NO-induced alternative pathway, through changes in the ROS/RNS balance, in order to reduce oxidative damage and preserve placental function in pregnancy.

Nutritional Models of Type 2 Diabetes Mellitus

In order to better understand the events that precede and precipitate the onset of type 2 diabetes (T2DM), several nutritional animal models have been developed. These models are generated by manipulating the diet of either the animal itself, or its mother during her pregnancy, and in comparison to traditional genetic and knock out models, have the advantage that they more accurately reflect the etiology of human T2DM. This chapter will discuss some of the most widely used nutritional models of T2DM: Diet-induced obesity (DIO) in adult rodents, and studies of offspring of mothers fed a low-protein, high-fat and/or high-sugar diet during pregnancy and/or lactation. Several common mechanisms have been identified through which these nutritional manipulations can lead to metabolic disease, including pancreatic beta-cell dysfunction, impaired insulin signaling in skeletal muscle, and the excess accumulation of visceral adipose tissue and consequent deposition of nonesterified fatty acids in peripheral tissues. In addition, there is an emerging concept that obesity/poor quality diets result in increased production and release of pro-inflammatory cytokines from adipose tissue leading to a state of chronic low-grade inflammation, and that this is likely to represent an important link between obesity/diet and metabolic dysfunction. The following chapter will discuss the most common nutritional models of T2DM in experimental animals, their application, and relationship to human etiology, and will highlight the important insights these models have provided into the pathogenesis of T2DM.

Maternal low protein exposure alters glucose tolerance and intestinal nutrient-responsive receptors and transporters expression of rat offspring

AIMS

Maternal protein malnutrition during perinatal period has long-term consequences on the offspring's metabolic phenotype. Here we determined the effects of maternal protein-restricted (PR) diet on offspring's metabolism in 3- and 12-week-old.

MAIN METHODS

Sprague-Dawley rats were fed with standard chow diet or PR diet during pregnancy and lactation. Food intake and body weight of offspring were measured weekly. The oral glucose tolerance tests were underwent, the pancreases were collected for histochemical staining, and the duodenum, jejunum and ileum were collected for gene and protein expression analysis in 3- and 12-week-old offspring.

KEY FINDINGS

PR offspring had significant lower body weight and persisted till 12-week-old. From 3- to 12-week-old, PR offspring presented considerably impaired glucose tolerance, while no marked change was shown in control rats. Additionally, the average islet size of PR offspring decreased significantly in 12-week-old. The mRNA and protein expression of nutrient-responsive receptors and transporters T1R3, SGLT1 and GLUT2 increased significantly in the intestine of 3-week-old PR offspring. And from 3- and 12-week-old, the increase tendency of expression subdued.

SIGNIFICANCE

These results suggest that maternal PR diet during critical developmental windows influences offspring metabolism, which may be subdued partially, but not be reversed completely by chow diet after weaning.

How Western Diet And Lifestyle Drive The Pandemic Of Obesity And Civilization Diseases

Westernized populations are plagued by a plethora of chronic non-infectious degenerative diseases, termed as "civilization diseases", like obesity, diabetes, cardiovascular diseases, cancer, autoimmune diseases, Alzheimer's disease and many more, diseases which are rare or virtually absent in hunter-gatherers and other non-westernized populations. There is a growing awareness that the cause of this amazing discrepancy lies in the profound changes in diet and lifestyle during recent human history. This paper shows that the transition from Paleolithic nutrition to Western diets, along with lack of corresponding genetic adaptations, cause significant distortions of the fine-tuned metabolism that has evolved over millions of years of human evolution in adaptation to Paleolithic diets. With the increasing spread of Western diet and lifestyle worldwide, overweight and civilization diseases are also rapidly increasing in developing countries. It is suggested that the diet-related key changes in the developmental process include an increased production of reactive oxygen species and oxidative stress, development of hyperinsulinemia and insulin resistance, low-grade inflammation and an abnormal activation of the sympathetic nervous system and the renin-angiotensin system, all of which play pivotal roles in the development of diseases of civilization. In addition, diet-related epigenetic changes and fetal programming play an important role. The suggested pathomechanism is also able to explain the well-known but not completely understood close relationship between obesity and the wide range of comorbidities, like type 2 diabetes mellitus, cardiovascular disease, etc., as diseases of the same etiopathology. Changing our lifestyle in accordance with our genetic makeup, including diet and physical activity, may help prevent or limit the development of these diseases.

Maternal Protein Malnutrition: Current and Future Perspectives of Spirulina Supplementation in Neuroprotection

Malnutrition has been widely recognized as a grave burden restricting the progress of underdeveloped and developing countries. Maternal, neonatal and postnatal nutritional immunity provides an effective approach to decrease the risk of malnutrition associated stress in adulthood. Particularly, maternal nutritional status is a critical contributor for determining the long-term health aspects of an offspring. Maternal malnutrition leads to increased risk of life, poor immune system, delayed motor development and cognitive dysfunction in the children. An effective immunomodulatory intervention using nutraceutical could be used to enhance immunity against infections. The immune system in early life possesses enormous dynamic capacity to manage both genetic and environment driven processes and can adapt to rapidly changing environmental exposures. These immunomodulatory stimuli or potent nutraceutical strategy can make use of early life plasticity to target pathways of immune ontogeny, which in turn could increase the immunity against infectious diseases arising from malnutrition. This review provides appreciable human and animal data showing enduring effects of protein deprivation on CNS development, oxidative stress and inflammation and associated behavioral and cognitive impairments. Relevant studies on nutritional supplementation and rehabilitation using Spirulina as a potent protein source and neuroprotectant against protein malnutrition (PMN) induced deleterious changes have also been discussed. However, there are many futuristic issues that need to be resolved for proper modulation of these therapeutic interventions to prevent malnutrition.

Maternal and Postnatal Supplementation of Fish Oil Improves Metabolic Health of Mouse Male Offspring

OBJECTIVE

Over half of American women of childbearing age have either obesity or overweight. Hence, maternal programming through diet is critical for prevention of diseases in the offspring. Clinical trials with fish oil (FO) report various health benefits; however, it remains unclear whether maternal and postnatal consumption of FO protects offspring from adverse effects of consuming a high-fat (HF) diet.

METHODS

Female mice were fed HF diets supplemented without (HF) or with FO from 8 weeks before pregnancy through lactation. A low-fat (LF) diet was included as a control diet. After weaning, male offspring from HF or FO dams were either continued on their respective diet (HF-HF and FO-FO) or switched to the other diet (HF-FO and FO-HF) and compared with LF. Phenotypic and mechanistic studies were performed.

RESULTS

FO-FO offspring demonstrated significantly higher glucose clearance and insulin sensitivity compared with other pups fed the HF diet (P < 0.05). Furthermore, FO-FO pups had lower adiposity, inflammation, and fat deposition in the liver, consistent with reduced markers of hepatic lipogenesis and increased hepatic lipid oxidation.

CONCLUSIONS

Supplementation of FO during pregnancy and early life is more beneficial than treating with FO either during pregnancy or in pups.

Exposure to maternal cafeteria diets during the suckling period has greater effects on fat deposition and Sterol Regulatory Element Binding Protein-1c (SREBP-1c) gene expression in rodent offspring compared to exposure before birth

Background

While the adverse metabolic effects of exposure to obesogenic diets during both the prenatal and early postnatal period are well established, the relative impact of exposure during these separate developmental windows remains unclear. This study aimed to assess the relative contribution of exposure to a maternal cafeteria diet during pregnancy and lactation on body weight, fat mass and expression of lipogenic and adipokine genes in the offspring.

Methods

Wistar rats were fed either a control chow (Control, n = 14) or obesogenic cafeteria diet (CAF, n = 12) during pregnancy and lactation. Pups were cross-fostered to another dam in either the same or different dietary group within 24 h of birth. Body weight, body fat mass and expression of lipogenic and adipokine genes in subcutaneous and visceral adipose tissues were determined in offspring at weaning and 3 weeks post-weaning.

Results

Offspring suckled by CAF dams had a lower body weight (P < 0.05), but ~ 2-fold higher percentage body fat at weaning than offspring suckled by Control dams (P < 0.01), independent of whether they were born to a Control or CAF dam. At 6 weeks of age, after all offspring were weaned onto standard chow, males and females suckled by CAF dams remained lighter (P < 0.05) than offspring suckled by Control dams, but the percentage fat mass was no longer different between groups. Sterol Regulatory Element Binding Protein-1c (SREBP-1c) mRNA expression was ~ 25% lower in offspring suckled by cafeteria dams in males at weaning (P < 0.05) and in females at 6 weeks of age (P < 0.05). Exposure to a cafeteria diet during the suckling period alone also resulted in increased adipocyte Peroxisome Proliferator Activated Receptor-γ (PPAR-γ) mRNA expression in females, and adiponectin and leptin mRNA expression in both sexes at weaning.

Conclusions

The findings from this study point to the critical role of the suckling period for deposition of adipose tissue in rodents, and the potential role of altered adipocyte gene expression in mediating these effects.

Origins in the Womb: Potential Role of the Physical Therapist in Modulating the Deleterious Effects of Obesity on Maternal and Offspring Health Through Movement Promotion and Prescription During Pregnancy

Maternal obesity and associated metabolic disease contribute to adverse outcomes in women and their offspring, and many of these outcomes have significant acute and chronic implications for both mother and neonate. Targeted movement (ie, physical activity or exercise training) during pregnancy has been shown to be safe and effective for improving many of these outcomes in women at a healthy weight and women who are obese. However, movement prescription and advice during pregnancy are often not addressed by health care providers; this situation creates a unique opportunity for physical therapists to use their expertise in movement with patients who are pregnant. The objective of this article is to briefly review the adverse maternal and neonatal outcomes associated with maternal obesity, the benefits of intentional maternal movement during pregnancy for women who are obese, the evidence-based guidelines for prescribing intentional movement during pregnancy for women who are obese, and the potential for physical therapists to become the driving force behind a necessary increase in movement levels in women who are pregnant. Physical therapists can play a significant role in encouraging movement in women who are healthy and women who have metabolic challenges during pregnancy and thus assist in combating the vicious cycle of obesity by improving maternal and offspring health.

Effect of a maternal cafeteria diet on the fatty acid composition of milk and offspring red blood cells

Previous studies have demonstrated that exposure to a maternal cafeteria diet during the lactation period alone produces detrimental effects to offspring metabolic health comparable to exposure during the entire perinatal period. The present study used a rodent model to assess the effect of a maternal cafeteria diet on the fat content and fatty acid composition of the dams' milk, and to determine the degree to which this was related to the fatty acid status of offspring on postnatal day 1 (PND1), weaning and 3 weeks post-weaning onto a standard rodent diet. As expected, omega-3 long chain polyunsaturated fatty acids (n-3 LCPUFA) content of both the milk and pup red blood cells (RBCs) was lower in the cafeteria (CAF) group on PND1. At 2 weeks post-partum, milk produced by CAF dams had a higher total fat, saturated fat and n-6 PUFA content, however these differences were modest in comparison with the differences in maternal intake between groups. Offspring suckled by CAF dams had a lower n-3 LCPUFA and n-6 PUFA status at weaning and higher trans fatty acid levels at both weaning and 6 weeks of age. These findings indicate that the fat content and fatty acid composition of the dam's milk is altered by exposure to a cafeteria diet. While it appears that the dam has a significant capacity to buffer the transfer of most dietary lipids into the milk, the trans fatty acids in particular appear to be readily transferred, resulting in persistent increases in trans fatty acid status of the offspring after weaning. The potential physiological implications of this warrants further examination.

A short-term transition from a high-fat diet to a normal-fat diet before pregnancy exacerbates female mouse offspring obesity

BACKGROUND/OBJECTIVES

Recent findings have highlighted the detrimental influence of maternal overnutrition and obesity on fetal development and early life development. However, there are no evidence-based guidelines regarding the optimal strategy for dietary intervention before pregnancy.

SUBJECTS/METHODS

We used a murine model to study whether switching from a high-fat (HF) diet to a normal-fat (NF) diet (H1N group) 1 week before pregnancy could lead to in utero reprogramming of female offspring obesity; comparator groups were offspring given a consistent maternal HF group or NF group until weaning. After weaning, all female offspring were given the HF diet for either 9 or 12 weeks before being killed humanely.

RESULTS

H1N treatment did not result in maternal weight loss before pregnancy. NF offsprings were neither obese nor glucose intolerant during the entire experimental period. H1N offsprings were most obese after the 12-week postweaning HF diet and displayed glucose intolerance earlier than HF offsprings. Our mechanistic study showed reduced adipocyte insulin receptor substrate 1 (IRS1) and hepatic IRS2 expression and increased adipocyte p-Ser(636/639) and p-Ser(612) of H1N or HF offspring compared with that in the NF offspring. Among all groups, the H1N offspring had lowest level of IRS1 and the highest levels of p-Ser(636/639) and p-Ser(612) in gonadal adipocyte. In addition, the H1N offspring further reduced the expression of Glut4 and Glut2, vs those of the HF offspring, which was lower compared with the NF offspring. There were also enhanced expression of genes inhibiting glycogenesis and decreased hepatic glycogen in H1N vs HF or NF offspring. Furthermore, we showed extremely higher expression of lipogenesis and adipogenesis genes in gonadal adipocytes of H1N offspring compared with all other groups.

CONCLUSIONS

Our results suggest that a transition from an HF diet to an NF diet shortly before pregnancy, without resulting in maternal weight loss, is not necessarily beneficial and may have deleterious effects on offspring.

Nutritional epigenetics with a focus on amino acids: implications for the development and treatment of metabolic syndrome

Recent findings from human and animal studies indicate that maternal undernutrition or overnutrition affects covalent modifications of the fetal genome and its associated histones that can be carried forward to subsequent generations. An adverse outcome of maternal malnutrition is the development of metabolic syndrome, which is defined as a cluster of disorders including obesity, hyperglycemia, hyperinsulinemia, hyperlipidemia, hypertension and insulin resistance. The transgenerational impacts of maternal nutrition are known as fetal programming, which is mediated by stable and heritable alterations of gene expression through covalent modifications of DNA and histones without changes in DNA sequences (namely, epigenetics). The underlying mechanisms include chromatin remodeling, DNA methylation (occurring at the 5'-position of cytosine residues within CpG dinucleotides), histone modifications (acetylation, methylation, phosphorylation, ubiquitination and sumoylation) and expression and activity of small noncoding RNAs. The enzymes catalyzing these reactions include S-adenosylmethionine-dependent DNA and protein methyltransferases, DNA demethylases, histone acetylase (lysine acetyltransferase), general control nonderepressible 5 (GCN5)-related N-acetyltransferase (a superfamily of acetyltransferase) and histone deacetylase. Amino acids (e.g., glycine, histidine, methionine and serine) and vitamins (B6, B12 and folate) play key roles in provision of methyl donors for DNA and protein methylation. Therefore, these nutrients and related metabolic pathways are of interest in dietary treatment of metabolic syndrome. Intervention strategies include targeting epigenetically disturbed metabolic pathways through dietary supplementation with nutrients (particularly functional amino acids and vitamins) to regulate one-carbon-unit metabolism, antioxidative reactions and gene expression, as well as protein methylation and acetylation. These mechanism-based approaches may effectively improve health and well-being of affected offspring.

Moderately increased maternal dietary energy intake delays foetal skeletal muscle differentiation and maturity in pigs

OBJECTIVES

This study aimed to evaluate the effects of moderately increased maternal dietary energy intake during gestation on foetal skeletal muscle development and metabolism with pig as a model.

METHODS

Twelve primiparous purebred Large White sows (initial body weight 135.5 ± 1.6 kg) were allocated to one of two energy intake treatments: normal-energy-intake group (Con, 30.96 MJ DE/day) as recommended by the National Research Council (NRC; 2012) and high-energy-intake group (HE, 34.15 MJ DE/day). The nutritional treatments were introduced from mating to day 90 of gestation. On day 90 of gestation, foetuses were examined by morphological, biochemical and molecular analysis of the longissimus muscle. Umbilical vein serum hormones were measured.

RESULTS

Sow body weight was increased in HE group compared with Con group (P < 0.05), whereas foetal myofibre density was decreased (P < 0.05). Meanwhile, protein concentration, creatine kinase and lactate dehydrogenase activities and umbilical vein serum triiodothyronine (T3) concentration were decreased in HE foetuses (P < 0.05). Maternal HE diets decreased the mRNA abundance of muscle growth-related genes, myosin heavy-chain (MYH/MyHC) genes (MYH2 and MYH1) and insulin-like growth factor 1 and insulin growth factor-binding protein 5 (P < 0.05). Furthermore, the protein expressions of myogenic differentiation factor 1, myogenin and fast-MyHC isoforms were reduced in HE foetuses (P < 0.05).

CONCLUSION

Our results suggest that moderately increased maternal dietary energy intake delays the differentiation and maturation in skeletal muscle of the foetus on day 90 of gestation.

Maternal and neonatal outcomes for pregnancies before and after gastric bypass surgery

BACKGROUND

Interaction between maternal obesity, intrauterine environment and adverse clinical outcomes of newborns has been described.

METHODS

Using statewide birth certificate data, this retrospective, matched-control cohort study compared paired birth weights and complications of infants born to women before and after Roux-en-Y gastric bypass surgery (RYGB) and to matched obese non-operated women in several different groups. Women who had given birth to a child before and after RYGB (group 1; n=295 matches) and women with pregnancies after RYGB (group 2; n=764 matches) were matched to non-operated women based on age, body mass index (BMI) prior to both pregnancy and RYGB, mother's race, year of mother/s birth, date of infant births and birth order. In addition, birth weights of 13 143 live births before and/or after RYGB of their mothers (n=5819) were compared (group 3).

RESULTS

Odds ratios (ORs) for having a large-for-gestational-age (LGA) neonate were significantly less after RYGB than for non-surgical mothers: ORs for groups 1 and 2 were 0.19 (0.08-0.38) and 0.33 (0.21-0.51), respectively. In contrast, ORs in all three groups for risk of having a small for gestational age (SGA) neonate were greater for RYGB mothers compared to non-surgical mothers (ORs were 2.16 (1.00-5.04); 2.16 (1.43-3.32); and 2.25 (1.89-2.69), respectively). Neonatal complications were not different for group 1 RYGB and non-surgical women for the first pregnancy following RYGB. Pregnancy-induced hypertension and gestational diabetes were significantly lower for the first pregnancy of mothers following RYGB compared to matched pregnancies of non-surgical mothers.

CONCLUSION

Women who had undergone RYGB not only had lower risk for having an LGA neonate compared to BMI-matched mothers, but also had significantly higher risk for delivering an SGA neonate following RYGB. RYGB women were less likely than non-operated women to have pregnancy-related hypertension and diabetes.

Impact of maternal obesity on offspring adipose tissue: lessons for the clinic

Maternal obesity is a major risk factor for the subsequent development of obesity and Type 2 diabetes in the child. This relationship appears to be driven largely by the exposure of the fetus to an increased nutrient supply during critical periods of development, which results in persistent changes in the structure and function of key systems involved in the regulation of energy balance, appetite and fat deposition. One of the key targets is the fat cell, or adipocyte, in which prenatal overnutrition programs a heightened capacity for fat storage. The increasing prevalence of maternal obesity has led to an urgent need for strategies to break the resulting intergenerational cycle of obesity and metabolic disease. This review will discuss the relationship between maternal obesity and poor metabolic health of the offspring, with a particular focus on the involvement of adipose tissue, recent clinical studies examining potential strategies for intervention and priority areas for further research.

Mechanisms by which maternal obesity programs offspring for obesity: evidence from animal studies

Maternal obesity can profoundly affect offspring phenotype and predisposition to obesity and metabolic disease. Carefully controlled studies in precocial and altricial mammalian species provide insights into the involved mechanisms. These include programming of hypothalamic appetite-regulating centers to increase orexigenic relative to anorexigenic drive; increasing maternal, fetal, and offspring adrenal and peripheral tissue glucocorticoid production; and increasing maternal oxidative stress. Outcomes often show offspring sex differences that may play a role in the differential susceptibility of males and females to later-life obesity and other related metabolic diseases.

Periconception weight loss: common sense for mothers, but what about for babies?

Obesity in the childbearing population is increasingly common. Obesity is associated with increased risk for a number of maternal and neonatal pregnancy complications. Some of these complications, such as gestational diabetes, are risk factors for long-term disease in both mother and baby. While clinical practice guidelines advocate for healthy weight prior to pregnancy, there is not a clear directive for achieving healthy weight before conception. There are known benefits to even moderate weight loss prior to pregnancy, but there are potential adverse effects of restricted nutrition during the periconceptional period. Epidemiological and animal studies point to differences in offspring conceived during a time of maternal nutritional restriction. These include changes in hypothalamic-pituitary-adrenal axis function, body composition, glucose metabolism, and cardiovascular function. The periconceptional period is therefore believed to play an important role in programming offspring physiological function and is sensitive to nutritional insult. This review summarizes the evidence to date for offspring programming as a result of maternal periconception weight loss. Further research is needed in humans to clearly identify benefits and potential risks of losing weight in the months before conceiving. This may then inform us of clinical practice guidelines for optimal approaches to achieving a healthy weight before pregnancy.

Endocannabinoid crosstalk between placenta and maternal fat in a baboon model (Papio spp.) of obesity

INTRODUCTION

Maternal obesity (MO) remains a serious obstetric problem with acute and chronic morbidities for both mothers and offspring. The mechanisms underlying these adverse consequences of MO remain unknown. Endocannabinoids (ECB) are neuromodulatory lipids released from adipocytes and other tissues. Metabolic crosstalk between placenta and adipocytes may mediate sequelae of MO. The goal of this study was to elucidate placental and systemic ECB in MO.

MATERIAL AND METHODS

Placentas, sera, and subcutaneous fat were collected at Cesarean sections performed near term (0.9 G) in four non-obese (nOB) and four obese (OB) baboons (Papio spp.). Concentrations of anandamide (AEA) and 2-arachidonoylglycerol (2-AG) were measured by liquid chromatography coupled to tandem mass spectrometry. AEA and 2-AG pathways were characterized in placentas by Q-RT-PCR, Western blot and immunohistochemistry.

RESULTS

Placental 2-AG levels were lower and maternal fat AEA levels were higher in OB (1254.1 ± 401.3 nmol/kg and 17.3 ± 4 nmol/kg) vs. nOB (3124.2 ± 557.3 nmol/kg and 3.1 ± 0.6 nmol/kg) animals. Concentrations of 2-AG correlated positively between maternal fat and placenta (r = 0.82, p = 0.013), but correlated negatively with maternal leptin concentrations (r = -0.72, p = 0.04 and r = -0.83, p = 0.01, respectively).

CONCLUSION

This is the first study to demonstrate differential ECB pathway regulation in maternal fat and placenta in MO. Differential regulation and function exist for AEA and 2-AG as the major ECB pathways in placenta.

Endocrine pancreatic development: impact of obesity and diet

During embryonic development, multipotent endodermal cells differentiate to form the pancreas. Islet cell clusters arising from the pancreatic bud form the acini tissue and exocrine ducts whilst pancreatic islets form around the edges of the clusters. The successive steps of islet differentiation are controlled by a complex network of transcription factors and signals that influence cell differentiation, growth and lineage. A Westernized lifestyle has led to an increased consumption of a high saturated fat diet, and an increase in maternal obesity. The developing fetus is highly sensitive to the intrauterine environment, therefore any alteration in maternal nutrition during gestation and lactation which affects the in-utero environment during the key developmental phases of the pancreas may change the factors controlling β-cell development and β-cell mass. Whilst the molecular mechanisms behind the adaptive programming of β-cells are still poorly understood it is established that changes arising from maternal obesity and/or over-nutrition may affect the ability to maintain fetal β-cell mass resulting in an increased risk of type 2 diabetes in adulthood.

Early life stress interacts with the diet deficiency of omega-3 fatty acids during the life course increasing the metabolic vulnerability in adult rats

Early stress can cause metabolic disorders in adulthood. Omega-3 polyunsaturated fatty acids (n-3 PUFAs) deficiency has also been linked to the development of metabolic disorders. The aim of this study was to assess whether an early stressful event such as maternal separation interacts with the nutritional availability of n-3 PUFAs during the life course on metabolic aspects. Litters were randomized into: maternal separated (MS) and non-handled (NH). The MS group was removed from their dam for 3 hours per day and put in an incubator at 32°C on days 1° to 10° postnatal (PND). On PND 35, males were subdivided into diets that were adequate or deficient in n-3 PUFAs, and this intervention was applied during the subsequent 15 weeks. Animal's body weight and food consumption were measured weekly, and at the end of the treatment tissues were collected. MS was associated with increased food intake (p = 0.047) and weight gain (p = 0.012), but no differences were found in the NPY hypothalamic content between the groups. MS rats had also increased deposition of abdominal fat (p<0.001) and plasma triglycerides (p = 0.018) when compared to the NH group. Interactions between early life stress and n-3 PUFAs deficiency were found in plasma insulin (p = 0.033), HOMA index (p = 0.049), leptin (p = 0.010) and liver PEPCK expression (p = 0.050), in which the metabolic vulnerability in the MS group was aggravated by the n-3 PUFAs deficient diet exposure. This was associated with specific alterations in the peripheral fatty acid profile. Variations in the neonatal environment interact with nutritional aspects during the life course, such as n-3 PUFAs diet content, and persistently alter the metabolic vulnerability in adulthood.

Omega-6 polyunsaturated fatty acids and the early origins of obesity

PURPOSE OF REVIEW

The incidence of obesity and its related metabolic disorders has increased significantly over the past 3 decades, culminating in the current global epidemic of metabolic disease and leading to the search for contributing factors. Exposure of the developing foetus/neonate to a typical Western diet increases their risk of obesity and metabolic disorders throughout the life-course, creating an intergenerational cycle of metabolic disease. In Western countries, this epidemic of metabolic disease has coincided with a marked increase in the intake of omega-6 polyunsaturated fatty acids (omega-6 PUFA), leading to suggestions that the two may be causally related.

RECENT FINDINGS

Recent studies have emphasized the proadipogenic properties of the omega-6 PUFA, and provided evidence that rodents fed on diets with omega-6 PUFA contents similar to the typical US diet (6-8% energy) have an increased fat mass. Importantly, recent studies have shown that perinatal exposure to a high omega-6 PUFA diet results in a progressive accumulation of body fat across generations.

SUMMARY

This review highlights the recent evidence supporting the role of the omega-6 PUFA in the early life origins of obesity and metabolic disease, the need for more clinical studies and the potential need for health agencies to re-evaluate current recommendations to further increase omega-6 PUFA intakes.

Nutritional approaches to breaking the intergenerational cycle of obesity

The link between poor maternal nutrition and an increased burden of disease in subsequent generations has been widely demonstrated in both human and animal studies. Historically, the nutritional challenges experienced by pregnant and lactating women were largely those of insufficient calories and severe micronutrient deficiencies. More recently, however, Western societies have been confronted with a new nutritional challenge; that of maternal obesity and excessive maternal intake of calories, fat, and sugar. Exposure of the developing fetus and infant to this obesogenic environment results in an increased risk of obesity and metabolic disease later in life. Furthermore, increased caloric, fat, and sugar intake can occur in conjunction with micronutrient deficiency, which may further exacerbate these programming effects. In light of the current epidemic of obesity and metabolic disease, attention has now turned to identifying nutritional interventions for breaking this intergenerational obesity cycle. In this review, we discuss the approaches that have been explored to date and highlight the need for further research.