Carbohydrate and lipid metabolism in pregnancy: normal compared with gestational diabetes mellitus

The effect of reproductive state on activity budget, feeding behavior, and urinary C-peptide levels in wild female Assamese macaques

Abstract

The source of maternal energy supporting reproduction (i.e., stored or incoming) is an important factor determining different breeding strategies (capital, income or mixed) in female mammals. Key periods of energy storage and allocation might induce behavioral and physiological shifts in females, and investigating their distribution throughout reproduction helps in determining vulnerable phases shaping female reproductive success. Here, we examined the effects of reproductive state on activity budget, feeding behavior, and urinary C-peptide (uCP) levels, a physiological marker of energy balance, in 43 wild female Assamese macaques (Macaca assamensis). Over a 13-month study period, we collected 96,266 instantaneous records of activity and 905 urine samples. We found that early lactating females and non-gestating–non-lactating females follow an energy-saving strategy consisting of resting more at the expense of feeding and consuming mostly fruits which contributed to enhancing their energy intake and feeding efficiency. We found an opposite pattern in gestating and late lactating females who feed more at the expense of resting and consume mostly seeds, providing a fiber-rich diet. Storing food into cheek pouches increased throughout gestation while it decreased all along with lactation. Lastly, we found the highest uCP levels during late gestation. Our results reflect different feeding adaptations in response to the energetic costs of reproduction and suggest a critical role of fat accumulation before conception and metabolizing fat during gestation and lactation. Overall, our study provides an integrative picture of the energetics of reproduction in a seasonal species and contributes to our understanding of the diversity of behavioral and physiological adaptations shaping female reproductive success.

Significance statement

To offset their substantial energetic investment in reproduction, mammalian females may modify their behavior and the way they extract energy from their environment. In addition, as a result of heightened energy expenditure, female reproduction might trigger physiological shifts. To date, most studies investigated the energetic costs of female reproduction using either a behavioral or a physiological approach. To arrive at a more comprehensive picture, we combined behavioral data with a physiological marker of energy balance, i.e., urinary C-peptide, in a seasonal primate species in its natural habitat. Our results indicate that throughout the reproductive cycle, behavioral and physiological adaptations operate concomitantly, inducing modifications in female activity budget, feeding behavior, and suggesting shifts in fat use. Overall, our results illustrate the relevance of combining data on behavior and hormones to investigate breeding strategies in coping with the energetic costs of reproduction.

Low-carbohydrate diet and maternal glucose metabolism in Chinese pregnant women

Few studies have suggested that long-term adherence to low-carbohydrate diets (LCD) may affect maternal glucose metabolism in Western countries. We aimed to investigate the association between LCD during pregnancy and glucose metabolism in a Chinese population. A total of 1018 women in mid-pregnancy were recruited in 2017-2018. Participants underwent a 75 g oral glucose tolerance test (OGTT). Daily dietary intakes over the past month were accessed using a validated FFQ. The overall, animal and vegetable LCD scores which represent adherence to different low-carbohydrate dietary patterns were calculated. Mixed linear regression and generalised linear mixed regression were conducted to evaluate the associations between LCD scores and maternal glucose metabolism. Of the 1018 subjects, 194 (19·1 %) were diagnosed with gestational diabetes mellitus (GDM). The overall LCD score (β: 0·024, se 0·008, PFDR = 0·02) and animal LCD score (β: 0·023, se 0·008, PFDR = 0·02) were positively associated with OGTT 1-h glucose. No significant associations were found between the three different LCD scores with fasting plasma glucose, OGTT 2-h glucose, or insulin resistance, respectively. Compared with the lowest quartile, the crude OR of GDM for the highest quartile were 1·84 (95 % CI 1·14, 2·95) for overall LCD score (Pfor trend = 0·02) and 1·56 (95 % CI 1·00, 2·45) for animal LCD score (Pfor trend = 0·02). However, these associations became non-significant after adjustment for covariates. In conclusion, a low-carbohydrate dietary pattern with high animal protein and fat is associated with higher postprandial 1-h glucose levels in Chinese pregnant women.

Multidisciplinary management of pregnancy and labour in a patient with glycogen storage disease type 1a

Glycogen storage disease type 1a (GSD 1a) is a metabolic disorder caused by deficiency of an enzyme required for glycogen breakdown, causing hypoglycaemia and lactic acidosis. Metabolic derangements cause disease manifestations affecting the kidneys, liver and platelet function. Physiological changes in pregnancy worsen fasting intolerance and increase reliance on exogenous glucose to avoid lactic acidosis. Fetal macrosomia and declining respiratory function result in high rates of caesarean sections. We report the multidisciplinary team (MDT) management of a 25-year-old woman with GSD 1a in an unplanned pregnancy. Existing percutaneous endoscopic gastrostomy tube feeding, alongside high-calorie drinks and intravenous dextrose during labour, managed the risks of hypoglycaemia and lactic acidosis. Metabolic parameters were regularly monitored and fortnightly growth scans were assessed for macrosomia. Allopurinol was continued throughout the pregnancy to reduce the risk of hyperuricaemia. MDT management optimised maternal and fetal care throughout pregnancy and labour, resulting in a successful vaginal delivery.

Melatonin regulates maternal pancreatic remodeling and B-cell function during pregnancy and lactation

The endocrine pancreas of pregnant rats shows evident plasticity, which allows the morphological structures to return to the nonpregnant state right after delivery. Furthermore, it is well-known the role of melatonin in the maintenance of the endocrine pancreas and its tropism. Studies indicate increasing nocturnal serum concentrations of maternal melatonin during pregnancy in both humans and rodents. The present study investigated the role of melatonin on energy metabolism and in pancreatic function and remodeling during pregnancy and early lactation in rats. The results confirm that the absence of melatonin during pregnancy impairs glucose metabolism. In addition, there is a dysregulation in insulin secretion at various stages of the development of pregnancy and an apparent failure in the glucose-stimulated insulin secretion during the lactation period, evidencing the role of melatonin on the regulation of insulin secretion. This mechanism seems not to be dependent on the antioxidant effect of melatonin and probably dependent on MT2 receptors. We also observed changes in the mechanisms of death and cell proliferation at the end of pregnancy and beginning of lactation, crucial periods for pancreatic remodeling. The present observations strongly suggest that both functionality and remodeling of the endocrine pancreas are impaired in the absence of melatonin and its adequate replacement, mimicking the physiological increase seen during pregnancy, is able to reverse some of the damage observed. Thus, we conclude that pineal melatonin is important to metabolic adaptation to pregnancy and both the functionality of the beta cells and the remodeling of the pancreas during pregnancy and early lactation, ensuring the return to nonpregnancy conditions.

Metabolic flexibility during normal pregnancy allows appropriate adaptation during gestation independently of BMI

BACKGROUND & AIMS

Overweight and obesity in reproductive-age women hasten the development of insulin resistance and increase risk for deterioration of pregnancy metabolism. These pregnancy-associated metabolic changes are similar to those of the metabolic syndrome. Thus, some metabolic flexibility must allow appropriate adaptation to the metabolic load that pregnancy imposes. We evaluated metabolic flexibility during uncomplicated pregnancy in women with pre-gestational normal weight or overweight.

METHODS

In 20 women with singleton pregnancies, pre-pregnancy BMI was categorized as normal-weight (Nw) or overweight (Ow). The women were seen quarterly, and fasting and postprandial blood samples were collected at each visit. Indirect fasting and/postprandial calorimetry was performed to evaluate metabolic flexibility (Δrespiratory quotient (RQ) = RQ_postprandial - RQ_fasting).

RESULTS

In the first trimester, metabolic flexibility was lower in the Ow group compared to the Nw group (0.031 ± 0.0131 vs 0.077 ± 0.018, respectively) without a statistically significant difference (p = 0.053). In the second trimester, the Ow group was significantly more flexible than the Nw group (0.190 ± 0.016 vs 0.077 ± 0.015, respectively (p = 0.004)). For the third trimester, the Ow and Nw groups did not differ in metabolic flexibility (0.074 ± 0.013 vs 0.087 ± 0.021, respectively) (p = 0.40). The most influential variables for metabolic flexibility during pregnancy were lactate, leptin, β-hydroxybutyrate, glycerol, aromatic amino acids, medium and long chain acylcarnitine's.

CONCLUSIONS

Our findings indicate that metabolic flexibility changes throughout pregnancy, independently of pre-pregnancy BMI. These changes maintain metabolic homeostasis between the mother and foetus, allowing for appropriate adjustments during pregnancy.

TIMER: A Clinical Study of Energy Restriction in Women with Gestational Diabetes Mellitus

Medical nutrition therapy is an integral part of gestational diabetes mellitus (GDM) management; however, the prescription of optimal energy intake is often a difficult task due to the limited available evidence. The present pilot, feasibility, parallel, open-label and non-randomized study aimed to evaluate the effect of a very low energy diet (VLED, 1600 kcal/day), or a low energy diet (LED, 1800 kcal/day), with or without personalized exercise sessions, among women with GDM in singleton pregnancies. A total of 43 women were allocated to one of four interventions at GDM diagnosis: (1) VLED (n = 15), (2) VLED + exercise (n = 4), (3) LED (n = 16) or (4) LED + exercise (n = 8). Primary outcomes were gestational weight gain (GWG), infant birth weight, complications at delivery and a composite outcomes score. Secondary outcomes included type of delivery, prematurity, small- for-gestational-age (SGA) or large-for-gestational-age (LGA) infants, macrosomia, Apgar score, insulin use, depression, respiratory quotient (RQ), resting metabolic rate (RMR) and middle-upper arm circumference (MUAC). GWG differed between intervention groups (LED median: 12.0 kg; VLED: 5.9 kg). No differences were noted in the type of delivery, infant birth weight, composite score, prevalence of prematurity, depression, RQ, Apgar score, MUAC, or insulin use among the four groups. Regarding components of the composite score, most infants (88.4%) were appropriate-for-gestational age (AGA) and born at a gestational age of 37-42 weeks (95.3%). With respect to the mothers, 9.3% experienced complications at delivery, with the majority being allocated at the VLED + exercise arm (p < 0.03). The composite score was low (range 0-2.5) for all mother-infant pairs, indicating a "risk-free" pregnancy outcome. The results indicate that adherence to a LED or VLED induces similar maternal, infant and obstetrics outcomes.

Lipid Metabolism Is Dysregulated before, during and after Pregnancy in a Mouse Model of Gestational Diabetes

The aim of the current study was to test the hypothesis that maternal lipid metabolism was modulated during normal pregnancy and that these modulations are altered in gestational diabetes mellitus (GDM). We tested this hypothesis using an established mouse model of diet-induced obesity with pregnancy-associated loss of glucose tolerance and a novel lipid analysis tool, Lipid Traffic Analysis, that uses the temporal distribution of lipids to identify differences in the control of lipid metabolism through a time course. Our results suggest that the start of pregnancy is associated with several changes in lipid metabolism, including fewer variables associated with de novo lipogenesis and fewer PUFA-containing lipids in the circulation. Several of the changes in lipid metabolism in healthy pregnancies were less apparent or occurred later in dams who developed GDM. Some changes in maternal lipid metabolism in the obese-GDM group were so late as to only occur as the control dams' systems began to switch back towards the non-pregnant state. These results demonstrate that lipid metabolism is modulated in healthy pregnancy and the timing of these changes is altered in GDM pregnancies. These findings raise important questions about how lipid metabolism contributes to changes in metabolism during healthy pregnancies. Furthermore, as alterations in the lipidome are present before the loss of glucose tolerance, they could contribute to the development of GDM mechanistically.

Bioenergetics adaptations and redox homeostasis in pregnancy and related disorders

Pregnancy is a challenging physiological process that involves maternal adaptations to the increasing energetics demands imposed by the growing conceptus. Failure to adapt to these requirements may result in serious health complications for the mother and the baby. The mitochondria are biosynthetic and energy-producing organelles supporting the augmented energetic demands of pregnancy. Evidence suggests that placental mitochondria display a dynamic phenotype through gestation. At early stages of pregnancy placental mitochondria are mainly responsible for the generation of metabolic intermediates and reactive oxygen species (ROS), while at later stages of gestation, the placental mitochondria exhibit high rates of oxygen consumption. This review describes the metabolic fingerprint of the placental mitochondria at different stages of pregnancy and summarises key signs of mitochondrial dysfunction in pathological pregnancy conditions, including preeclampsia, gestational diabetes and intrauterine growth restriction (IUGR). So far, the effects of placental-driven metabolic changes governing the metabolic adaptations occurring in different maternal tissues in both, healthy and pathological pregnancies, remain to be uncovered. Understanding the function and molecular aspects of the adaptations occurring in placental and maternal tissue's mitochondria will unveil potential targets for further therapeutic exploration that could address pregnancy-related disorders. Targeting mitochondrial metabolism is an emerging approach for regulating mitochondrial bioenergetics. This review will also describe the potential therapeutic use of compounds with a recognised effect on mitochondria, for the management of preeclampsia.

Age at menarche, ideal cardiovascular health metrics, and risk of diabetes in adulthood: Findings from the REACTION study

BACKGROUND

Age at menarche was reported to be associated with the risk of diabetes. However, the impact of ideal cardiovascular health metrics (ICVHMs) on the association between age at menarche and adulthood diabetes risk was unclear.

METHODS

We included 121 431 women from the nationwide, population-based cohort of the REACTION study (Risk Evaluation of Cancers in Chinese Diabetic Individuals: a Longitudinal Study). The diagnosis of diabetes was based on the oral glucose tolerance test (OGTT) and glycosylated hemoglobin (HbA1c) measurement. Logistic regression and multiplicative interaction analysis were conducted to investigate the potential interaction effect between age at menarche and ICVHMs on the development of diabetes.

RESULTS

The multivariable-adjusted odds ratios of diabetes across categories of age at menarche (<14, 14-17, and > 17 years) were 1.22 (95% confidence interval [CI]: 1.17, 1.28), 1.00 (reference), and 0.89 (95% CI: 0.85, 0.93), respectively. In subgroup analysis, significant interactions were detected between total cholesterol/blood pressure levels and age at menarche regarding the risk of diabetes (P for interaction = .0091 and .0019, respectively). The increased risk associated with age at menarche <14 years was observed in participants with three or fewer ICVHMs, but not in women with four or more ICVHMs (P for interaction = .0001).

CONCLUSIONS

Age at menarche was inversely associated with the risk of diabetes in adulthood in Chinese women, and it appeared to be modified by the presence of ICVHMs. Further studies are needed to clarify the precise interrelationship and the generalizability of our results.

Modelling gestational diabetes mellitus: large animals hold great promise

Gestational diabetes mellitus (GDM) characterized by hyperglycemia during pregnancy is a risk factor for various maternal and fetal complications. The key pathophysiological mechanisms underlying its development have not been elucidated, largely due to the lack of a model that accurately simulates the major clinical and pathological features of human GDM. In this review, we discuss the refined criteria for an ideal animal model of GDM, focusing on the key clinical and pathophysiological characteristics of human GDM. We provide a comprehensive overview of different models and currently used species for GDM research. In general, insulin insufficiency consequent to pancreatic β-cell death represents the current leading strategy to mimic human GDM-like hyperglycemia in animals. Nonetheless, these models have a limited capacity to mimic the natural history of GDM, the marked alteration in circulating estrogen/ progestogen, obesity and its related metabolic complications. We discuss emerging evidence of the increased susceptibility to GDM in rodents and large animals with genetic modifications in pregnancy-related hormones. An appraisal of current GDM models suggests that a combination strategy involving dietary stress, pregnancy-related hormones, insulin resistance and metabolic disorders might enable the development of better GDM models and expedite the translation of basic research findings to GDM treatment.

Successful pregnancy in a woman with glycogen storage disease type 6

Glycogen storage disease type VI is caused by biallelic variants in the PYGL gene that result in hepatic glycogen phosphorylase deficiency. The disorder is clinically characterized by hepatomegaly and recurrent ketotic hypoglycemia from infancy. Although most patients reach adulthood without major complications, no pregnancies in women with GSD VI have been reported so far. We report on a successful pregnancy in a GSD VI patient that resulted in a healthy offspring and describe the pre- and perinatal management.

Maternal lipid levels in preeclampsia: singleton vs. twin pregnancies

OBJECTIVE

To compare the maternal lipid levels in preeclampsia (PE) patients between singleton and twin pregnancies.

METHODS

In this retrospective study, pregnant women with PE were divided into singleton group (n = 702) and twin group (n = 198). Serum lipids which include total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) were measured and the TC/HDL-C ratio, TG/HDL-C ratio, and LDL-C/HDL-C ratio were calculated and compared between the two groups. Covariance analysis was used to correct the potential factors affecting serum lipid levels such as maternal age, pre-pregnancy body mass index, gestational weight gain, etc.

RESULTS

The levels of TC, TG, LDL-C, and TC/HDL-C ratio, TG/HDL-C ratio, LDL-C/HDL-C ratio in twin PE were significantly higher than those in singleton PE group, and there was no significant difference in the level of HDL-C between the two groups. In late-onset PE patients, the lipid levels of TC, TG, LDL-C, and TC/HDL-C ratio, TG/HDL-C ratio, LDL-C/HDL-C ratio in twin PE group were significantly higher than those in singleton PE group, with no significant difference in the level of HDL-C. However, in early-onset PE patients, there were no significant differences in the lipid levels between the two groups.

CONCLUSIONS

There were more obvious lipid disturbances such as higher levels of TC, TG, LDL-C, and TC/HDL-C ratio, TG/HDL-C ratio, LDL-C/HDL-C ratio in twin PE group than singleton PE group. The differences of lipid levels appeared mainly in late-onset PE group, while the lipid levels in twin PE group were similar to those in singleton PE group during pregnancy in early-onset PE group.

Central actions of insulin during pregnancy and lactation

Pregnancy and lactation are highly metabolically demanding states. Maternal glucose is a key fuel source for the growth and development of the fetus, as well as for the production of milk during lactation. Hence, the maternal body undergoes major adaptations in the systems regulating glucose homeostasis to cope with the increased demand for glucose. As part of these changes, insulin levels are elevated during pregnancy and lower in lactation. The increased insulin secretion during pregnancy plays a vital role in the periphery; however, the potential effects of increased insulin action in the brain have not been widely investigated. In this review, we consider the impact of pregnancy on brain access and brain levels of insulin. Moreover, we explore the hypothesis that pregnancy is associated with site-specific central insulin resistance that is adaptive, allowing for the increases in peripheral insulin secretion without the consequences of increased central and peripheral insulin functions, such as to stimulate glucose uptake into maternal tissues or to inhibit food intake. Conversely, the loss of central insulin actions may impair other functions, such as insulin control of the autonomic nervous system. The potential role of low insulin in facilitating adaptive responses to lactation, such as hyperphagia and suppression of reproductive function, are also discussed. We end the review with a list of key research questions requiring resolution.

Relationships between Maternal Dietary Patterns and Blood Lipid Levels during Pregnancy: A Prospective Cohort Study in Shanghai, China

The relationships between maternal dietary patterns and blood lipid profile during pregnancy have not been well understood. We aimed to analyze the dietary patterns of pregnant women and their associations with blood lipid concentrations during pregnancy. A cohort of 1008 Chinese pregnant women were followed from 10-15 weeks of gestation to delivery. Their dietary patterns were identified using a principal component analysis. The relationships between dietary pattern score and maternal blood lipid concentrations were assessed using both multivariate linear regression models and generalized estimating equation (GEE) models. Five different dietary patterns were identified. GEE showed that a high score for the fish-shrimps pattern was associated with higher concentrations of total cholesterol (TC) (β = 0.11), low-density lipoprotein cholesterol (LDL-C) (β = 0.07), and high-density lipoprotein cholesterol (HDL-C) (β = 0.03), with all p values < 0.001. In contrast, a high tubers-fruit-vegetables pattern score was associated with lower concentrations of TC (β = -0.12), LDL-C (β = -0.07), and HDL-C (β = -0.03), with all p values < 0.001. In addition, dietary protein, carbohydrate, and cholesterol intake significantly contributed to the associations between the fish-shrimps dietary pattern and blood lipid concentrations. Predominant seafood consumption is associated with higher cholesterol concentrations, whereas predominant tuber, fruit, and vegetable consumptions are associated with lower cholesterol concentrations during pregnancy.

Adverse Pregnancy Outcomes and Cardiovascular Disease Risk: Unique Opportunities for Cardiovascular Disease Prevention in Women: A Scientific Statement From the American Heart Association

This statement summarizes evidence that adverse pregnancy outcomes (APOs) such as hypertensive disorders of pregnancy, preterm delivery, gestational diabetes, small-for-gestational-age delivery, placental abruption, and pregnancy loss increase a woman's risk of developing cardiovascular disease (CVD) risk factors and of developing subsequent CVD (including fatal and nonfatal coronary heart disease, stroke, peripheral vascular disease, and heart failure). This statement highlights the importance of recognizing APOs when CVD risk is evaluated in women, although their value in reclassifying risk may not be established. A history of APOs is a prompt for more vigorous primordial prevention of CVD risk factors and primary prevention of CVD. Adopting a heart-healthy diet and increasing physical activity among women with APOs, starting in the postpartum setting and continuing across the life span, are important lifestyle interventions to decrease CVD risk. Lactation and breastfeeding may lower a woman's later cardiometabolic risk. Black and Asian women experience a higher proportion APOs, with more severe clinical presentation and worse outcomes, than White women. More studies on APOs and CVD in non-White women are needed to better understand and address these health disparities. Future studies of aspirin, statins, and metformin may better inform our recommendations for pharmacotherapy in primary CVD prevention among women who have had an APO. Several opportunities exist for health care systems to improve transitions of care for women with APOs and to implement strategies to reduce their long-term CVD risk. One proposed strategy includes incorporation of the concept of a fourth trimester into clinical recommendations and health care policy.

Exercise as a Therapeutic Intervention in Gestational Diabetes Mellitus

Gestational Diabetes Mellitus (GDM) is defined as any degree of glucose intolerance with onset or first recognition during pregnancy. Regular exercise is important for a healthy pregnancy and can lower the risk of developing GDM. For women with GDM, exercise is safe and can affect the pregnancy outcomes beneficially. A single exercise bout increases skeletal muscle glucose uptake, minimizing hyperglycemia. Regular exercise training promotes mitochondrial biogenesis, improves oxidative capacity, enhances insulin sensitivity and vascular function, and reduces systemic inflammation. Exercise may also aid in lowering the insulin dose in insulin-treated pregnant women. Despite these benefits, women with GDM are usually inactive or have poor participation in exercise training. Attractive individualized exercise programs that will increase adherence and result in optimal maternal and offspring benefits are needed. However, as women with GDM have a unique physiology, more attention is required during exercise prescription. This review (i) summarizes the cardiovascular and metabolic adaptations due to pregnancy and outlines the mechanisms through which exercise can improve glycemic control and overall health in insulin resistance states, (ii) presents the pathophysiological alterations induced by GDM that affect exercise responses, and (iii) highlights cardinal points of an exercise program for women with GDM.

Pregnancy-induced changes in β-cell function: what are the key players?

Maternal metabolic adaptations during pregnancy ensure appropriate nutrient supply to the developing fetus. This is facilitated by reductions in maternal peripheral insulin sensitivity, which enables glucose to be available in the maternal circulation for transfer to the fetus for growth. To balance this process and avoid excessive hyperglycaemia and glucose intolerance in the mother during pregnancy, maternal pancreatic β-cells undergo remarkable changes in their function including increasing their proliferation and glucose-stimulated insulin secretion. In this review we examine how placental and maternal hormones work cooperatively to activate several signalling pathways, transcription factors and epigenetic regulators to drive adaptations in β-cell function during pregnancy. We also explore how adverse maternal environmental conditions, including malnutrition, obesity, circadian rhythm disruption and environmental pollutants, may impact the endocrine and molecular mechanisms controlling β-cell adaptations during pregnancy. The available data from human and experimental animal studies highlight the need to better understand how maternal β-cells integrate the various environmental, metabolic and endocrine cues and thereby determine appropriate β-cell adaptation during gestation. In doing so, these studies may identify targetable pathways that could be used to prevent not only the development of pregnancy complications like gestational diabetes that impact maternal and fetal wellbeing, but also more generally the pathogenesis of other metabolic conditions like type 2 diabetes.

Hyperinsulinemia during pregnancy across varying degrees of glucose tolerance: An examination of the Kraft database

AIM

Hyperinsulinemia is a known underlying driver of metabolic disease; however, its role in pregnancy complications is less understood due to insulin measurement not being a part of standard clinical assessments. This study aimed to characterize hyperinsulinemia in pregnancy by gestational diabetes (GD) status using Kraft methodology.

METHODS

We analyzed historical data from 926 pregnant women who underwent a 100-g oral glucose tolerance test (OGTT), which included insulin measurement. Subjects were grouped by GD diagnosis status ("Normal", "Borderline", "GD") and insulin responses over 3 h were compared between groups.

RESULTS

"GD" was diagnosed in 20.3% of the subjects and 13.8% were grouped as "Borderline." The prevalence of hyperinsulinemia using the Kraft algorithm was 33.1% for Kraft IIB and 42.0% for Kraft III. Compared to normal glucose-tolerant mothers, individuals from the "Borderline" group had an exacerbated insulin response, although not to the same magnitude as those with "GD."

CONCLUSIONS

Dynamic OGTT insulin measurement during pregnancy may provide a meaningful assessment of metabolic risk among women who would otherwise not be diagnosed with GD.

apoA2 correlates to gestational age with decreased apolipoproteins A2, C1, C3 and E in gestational diabetes

INTRODUCTION

Pregnant women with gestational diabetes mellitus (GDM) are at risk of adverse outcomes, including gestational hypertension, pre-eclampsia, and preterm delivery. This study was undertaken to determine if apolipoprotein (apo) levels differed between pregnant women with and without GDM and if they were associated with adverse pregnancy outcome.

RESEARCH DESIGN AND METHODS

Pregnant women (46 women with GDM and 26 women without diabetes (ND)) in their second trimester were enrolled in the study. Plasma apos were measured and correlated to demographic, biochemical, and pregnancy outcome data.

RESULTS

apoA2, apoC1, apoC3 and apoE were lower in women with GDM compared with control women (p=0.0019, p=0.0031, p=0.0002 and p=0.015, respectively). apoA1, apoB, apoD, apoH, and apoJ levels did not differ between control women and women with GDM. Pearson bivariate analysis revealed significant correlations between gestational age at delivery and apoA2 for women with GDM and control women, and between apoA2 and apoC3 concentrations and C reactive protein (CRP) as a measure of inflammation for the whole group.

CONCLUSIONS

Apoproteins apoA2, apoC1, apoC3 and apoE are decreased in women with GDM and may have a role in inflammation, as apoA2 and C3 correlated with CRP. The fact that apoA2 correlated with gestational age at delivery in both control women and women with GDM raises the hypothesis that apoA2 may be used as a biomarker of premature delivery, and this warrants further investigation.

Prophylactic metformin after antenatal corticosteroids (PROMAC): a double blind randomized controlled trial

Background

Antenatal corticosteroids (ACS) are increasingly used to improve prematurity-related neonatal outcome. A recognized and common adverse effect from administration of antenatal corticosteroid is maternal hyperglycemia. Even normal pregnancy is characterized by relative insulin resistance and glucose intolerance. Treatment of maternal hyperglycemia after ACS might be indicated due to the higher risk of neonatal acidosis which may coincide with premature birth. Metformin is increasingly used to manage diabetes mellitus during pregnancy as it is effective and more patient friendly. There is no data on prophylactic metformin to maintain euglycemia following antenatal corticosteroids administration.

Methods

A double blind randomized trial. 103 women scheduled to receive two doses of 12-mg intramuscular dexamethasone 12-hour apart were separately randomized to take prophylactic metformin or placebo after stratification according to their gestational diabetes (GDM) status. First oral dose of allocated study drug was taken at enrolment and continued 500 mg twice daily for 72 hours if not delivered. Six-point blood sugar profiles were obtained each day (pre- and two-hour post breakfast, lunch and dinner) for up to three consecutive days. A hyperglycemic episode is defined as capillary glucose fasting/pre-meal ≥ 5.3 mmol/L or two-hour post prandial/meal ≥ 6.7 mmol/L. Primary outcome was hyperglycemic episodes on Day-1 (first six blood sugar profile points) following antenatal corticosteroids.

Results

Number of hyperglycemic episodes on the first day were not significantly different (mean ± standard deviation) 3.9 ± 1.4 (metformin) vs. 4.1 ± 1.6 (placebo) p = 0.64. Hyperglycemic episodes markedly reduced on second day in both arms to 0.9 ± 1.0 (metformin) vs. 1.2 ± 1.0 (placebo) p = 0.15 and further reduced to 0.6 ± 1.0 (metformin) vs. 0.7 ± 1.0 (placebo) p = 0.67 on third day. Hypoglycemic episodes during the 3-day study period were few and all other secondary outcomes were not significantly different.

Conclusions

In euglycemic and diet controllable gestational diabetes mellitus women, antenatal corticosteroids cause sustained maternal hyperglycemia only on Day-1. The magnitude of Day-1 hyperglycemia is generally low. Prophylactic metformin does not reduce antenatal corticosteroids’ hyperglycemic effect.

Trial registration

The trial is registered in the ISRCTN registry on May 4 2017 with trial identifier 10.1186/ISRCTN10156101.

Global metabolomic profiling reveals hepatic biosignatures that reflect the unique metabolic needs of late-term mother and fetus

OBJECTIVE

Gestational disorders including preeclampsia, growth restriction and diabetes are characterized, in part, by altered metabolic interactions between mother and fetus. Understanding their functional relevance requires metabolic characterization under normotypic conditions.

METHODS

We performed untargeted metabolomics on livers of pregnant, late-term C57Bl/6J mice (N = 9 dams) and their fetuses (pooling 4 fetuses/litter), using UPLC-MS/MS.

RESULTS

Multivariate analysis of 730 hepatic metabolites revealed that maternal and fetal metabolite profiles were highly compartmentalized, and were significantly more similar within fetuses (ρ_average = 0.81), or within dams (ρ_average = 0.79), than within each maternal-fetal dyad (ρ_average = - 0.76), suggesting that fetal hepatic metabolism is under distinct and equally tight metabolic control compared with its respective dam. The metabolite profiles were consistent with known differences in maternal-fetal metabolism. The reduced fetal glucose reflected its limited capacity for gluconeogenesis and dependence upon maternal plasma glucose pools. The fetal decreases in essential amino acids and elevations in their alpha-keto acid carnitine conjugates reflects their importance as secondary fuel sources to meet fetal energy demands. Whereas, contrasting elevations in fetal serine, glycine, aspartate, and glutamate reflects their contributions to endogenous nucleotide synthesis and fetal growth. Finally, the elevated maternal hepatic lipids and glycerol were consistent with a catabolic state that spares glucose to meet competing maternal-fetal energy demands.

CONCLUSIONS

The metabolite profile of the late-term mouse dam and fetus is consistent with prior, non-rodent analyses utilizing plasma and urine. These data position mouse as a suitable model for mechanistic investigation into how maternal-fetal metabolism adapts (or not) to gestational stressors.

Complex patterns of circulating fatty acid levels in gestational diabetes mellitus subclasses across pregnancy

BACKGROUND & AIMS

To investigate the relationship between maternal serum fatty acid levels and gestational diabetes mellitus (GDM) subtypes across pregnancy.

METHODS

A total of 680 singleton mothers enrolled in the Complex Lipids in Mothers and Babies (CLIMB) study in Chongqing, China were included. Clinical information and serum samples were collected at gestational weeks (GWs) 11-14, 22-28, and 32-34. 75 g Oral Glucose Tolerance Test (OGTT) was conducted at GW 24-28 and GDM subtypes divided into three groups using International Association of Diabetes and Pregnancy Study Group (IADPSG) guidelines criteria: elevated fasting plasma glucose (FPG group; n = 59); 1-h and/or 2-h post-load glucose (1h/2h-PG group; n = 94); combined group (FPG&1h/2h-PG group; n = 42). Non-GDM pregnancies were included (n = 485) as controls. Twenty fatty acids were quantified in serum using gas chromatography-mass spectrometry (GC-MS) analysis.

RESULTS

Overall, most serum fatty acid concentrations increased rapidly from the first to second trimester, followed by a plateauing or reduction in the third trimester (p < 0.001). In cross sectional analysis, fatty acid concentrations were significantly higher in the FPG group at GW 11-14 and decreased in the 1h/2h-PG group at GW 32-34, relative to controls. Moreover, higher α-linolenic acid (ALA; the second tertile: adjusted odds ratio [aOR] = 2.53, 95% CI: 1.17 to 5.47; the third tertile: aOR = 2.60, 95% CI: 1.20 to 5.65) and docosahexaenoic acid (DHA; the second tertile: aOR = 2.34, 95% CI: 1.10 to 4.97; the third tertile: aOR = 2.16, 95% CI: 1.00 to 4.63) were significantly associated with a higher risk of GDM in women with elevated fasting plasma glucose at GW 11-14 (first tertile as reference).

CONCLUSIONS

Our findings highlight the importance of considering GDM subtypes for the individualised management of GDM in pregnancy. ALA and DHA in early pregnancy are associated with a higher risk of FPG-GDM subtype. This has widespread implications when recommending n-3 PUFAs supplementation for women with GDM.

Association between metabolic syndrome and gestational diabetes mellitus in women and their children: a systematic review and meta-analysis

PURPOSE

The primary aim of this systematic review and meta-analysis was to determine the association between gestational diabetes mellitus (GDM) and metabolic syndrome (MetS) in women and children. Our secondary aim was to assess the development of MetS with respect to the elapsed time postpartum at which MetS was diagnosed.

METHODS

This review is registered with PROSPERO (CRD42020173319). PubMed, CINHAL, SCOPUS, and EMBASE databases were searched. Studies reporting on the rate of MetS in pregnant women with GDM, the rate of MetS in women with a history of GDM, and the rate of MetS in offspring exposed to GDM in utero compared to healthy controls were selected.

RESULTS

We identified 588 articles from the literature search. Fifty-one studies were included in the review and of those 35 were included in the meta-analysis. Quantitative summary measures showed that women with a history of GDM had an increased risk of developing MetS compared to those without a history of GDM (RR 2.36, 95% CI 1.77-3.14, 29 studies, 13,390 participants; heterogeneity: χ² p < 0.00001; I² = 93%). Offspring exposed to GDM in utero have an increased risk of developing MetS compared to those not exposed to GDM in utero. (RR 2.07, 95% CI 1.26-3.42, three studies, 4,421 participants; heterogeneity: χ² p = 0.33; I² = 12%). Women diagnosed with GDM have an increased risk of developing MetS during pregnancy (RR 20.51, 95% CI 5.04-83.55; three studies, 406 participants; heterogeneity: χ² p = 0.96; I² = 0%). Subgroup analysis revealed that MetS is diagnosed as early as <1 year postpartum in women with a history of GDM.

CONCLUSIONS/INTERPRETATION

Women with GDM have an increased risk of developing MetS during pregnancy. Women with a history of GDM and offspring exposed to GDM in utero have higher risks of developing MetS compared to those with no history of GDM. Metabolic syndrome in women with a history of GDM is seen as early as <1 year postpartum.

A non-targeted LC-MS metabolic profiling of pregnancy: longitudinal evidence from healthy and pre-eclamptic pregnancies

INTRODUCTION

Maternal metabolism changes substantially during pregnancy. However, few studies have used metabolomics technologies to characterize changes across gestation.

OBJECTIVES AND METHODS

We applied liquid chromatography-mass spectrometry (LC-MS) based non-targeted metabolomics to determine whether the metabolic profile of serum differs throughout the pregnancy between pre-eclamptic and healthy women in the FINNPEC (Finnish Genetics of Preeclampsia Consortium) Study. Serum samples were available from early and late pregnancy.

RESULTS

Progression of pregnancy had large-scale effects to the serum metabolite profile. Altogether 50 identified metabolites increased and 49 metabolites decreased when samples of early pregnancy were compared to samples of late pregnancy. The metabolic signatures of pregnancy were largely shared in pre-eclamptic and healthy women, only urea, monoacylglyceride 18:1 and glycerophosphocholine were identified to be increased in the pre-eclamptic women when compared to healthy controls.

CONCLUSIONS

Our study highlights the need of large-scale longitudinal metabolomic studies in non-complicated pregnancies before more detailed understanding of metabolism in adverse outcomes could be provided. Our findings are one of the first steps for a broader metabolic understanding of the physiological changes caused by pregnancy per se.

Changes in serum lipid levels during pregnancy in women with gestational diabetes. A narrative review

We review current knowledge on lipid metabolism changes during pregnancy with special focus on changes in gestational diabetes. In physiological pregnancy, total plasma cholesterol, triglyceride and HDL-cholesterol level rises, the atherogenic index (LDL-cholesterol / HDL-cholesterol remains unchanged. Compared with healthy women, women with GDM show more pronounced signs of mixed dyslipidaemia - increased levels of triglyceride, changes in cholesterol and lipoprotein concentrations with a shift towards greater small dense LDL subtractions, which is typical for insulin resistance states. Dyslipidaemia, particularly hypertriglyceridemia, is thought to be one of the key drivers of foetal macrosomia and that is why measurements of plasma lipids may be valuable in detecting the metabolic abnormality in GDM and in predicting foetal outcome. Dyslipidaemia in GDM is seen as proatherogenic and potentially harmful for the baby and therefore it should be monitored more carefully.

Maternal DNA Methylation During Pregnancy: a Review

Multiple environmental, behavioral, and hereditary factors affect pregnancy. Recent studies suggest that epigenetic modifications, such as DNA methylation (DNAm), affect both maternal and fetal health during the period of gestation. Some of the pregnancy-related risk factors can influence maternal DNAm, thus predisposing both the mother and the neonate to clinical adversities with long-lasting consequences. DNAm alterations in the promoter and enhancer regions modulate gene expression changes which play vital physiological role. In this review, we have discussed the recent advances in our understanding of maternal DNA methylation changes during pregnancy and its associated complications such as gestational diabetes and anemia, adverse pregnancy outcomes like preterm birth, and preeclampsia. We have also highlighted some major gaps and limitations in the area which if addressed might improve our understanding of pregnancy and its associated adverse clinical conditions, ultimately leading to healthy pregnancies and reduction of public health burden.

Nuclear receptors, gestational metabolism and maternal metabolic disorders

Normal pregnancy is characterised by a gradual alteration in metabolism that results in elevated serum bile acids, dyslipidaemia and impaired glucose tolerance in the third trimester. Nuclear receptors play important roles in regulating metabolic pathways that influence alterations in these parameters. There is evidence for altered function of FXR and LXR in gestation; these nuclear receptors play an integral role in bile acid and lipid homeostasis. There is some evidence for influence of clock genes in late pregnancy metabolic changes, and this may be linked to alterations in placental gene expression and function, thereby influencing fetal growth. This article will review the current data from human studies and investigation of animal models to illustrate the role of nuclear receptors (namely LXR, FXR, PPARs and clock genes) in gestational alterations in metabolism and the ways this may influence susceptibility to metabolic disorders of pregnancy such as gestational diabetes mellitus and intrahepatic cholestasis of pregnancy.

Nutritional and developmental programming effects of insulin

The discovery of insulin in 1921 was a major breakthrough in medicine and for therapy in patients with diabetes. The dramatic rise in the prevalence of overweight and obesity has been tightly linked to an increased prevalence of gestational diabetes mellitus (GDM), which poses major health concerns. Babies born to GDM mothers are more likely to develop obesity, type 2 diabetes and cardiovascular disease later in life. Evidence accumulated during the past two decades has revealed that high levels insulin, such as those observed during GDM, can have a widespread effect on the development and function of a variety of organs. This review summarises our current knowledge on the role of insulin in the placenta, cardiovascular system and brain during critical periods of development, as well as how it can contribute to lifelong metabolic regulation. We also discuss possible intervention strategies to ameliorate and hopefully reverse the developmental defects associated with obesity and GDM.

Association of Complement-Related Proteins in Subjects With and Without Second Trimester Gestational Diabetes

INTRODUCTION

Gestational Diabetes Mellitus (GDM) development is related to underlying metabolic syndrome that is associated with elevated complement C3 and C4. Elevated C3 levels have been associated with preeclampsia and the development of macrosomia.

METHODS

This case-control study included 34 pregnant women with GDM and 16 non-diabetic (ND) women in their second trimester. Complement-related proteins were measured and correlated with demographic, biochemical, and pregnancy outcome data.

RESULTS

GDM women were older with a higher BMI (p<0.001); complement C3, C4 and Factor-H were significantly elevated (p=0.001, p=0.05, p=0.01, respectively). When adjusted for age and BMI, Complement C3 (p=0.04) and Factor-H (p=0.04) remained significant. Partial correlation showed significant correlation between C4 with serum alanine aminotransferase (ALT) (p<0.05) and 2^nd term diastolic blood pressure (p<0.05); Factor-H and C-reactive protein (CRP; p<0.05). Pearson bivariate analysis revealed significant correlations between C3, C4, and Factor-H and CRP; p<0.05; C3 and gestational age at delivery (GA; p<0.05); C4 and ALT and second-trimester systolic blood pressure (STBP) (p=0.008 and p<0.05, respectively); Factor-H and glycated hemoglobin (HbA1c) (p<0.05). Regression analysis showed that the elevation of C3 could be accounted for by age, BMI, GA and CRP, with CRP being the most important predictor (p=0.02). C4 elevation could be accounted for by ALT, CRP and STBP. CRP predicted Factor-H elevation.

CONCLUSION

The increased C3, C4 and Factor-H during the second trimester of pregnancy in GDM are not independently associated with GDM; inflammation and high BMI may be responsible for their elevation. The elevation of second trimester C3 in GDM is associated with earlier delivery and further work is needed to determine if this is predictive.

Predictability of Macrosomic Birth based on Maternal Factors and Fetal Aneuploidy Screening Biochemical Markers in Hyperglycemic Mothers

Background: Macrosomic birth weight has been implicated as a significant risk factor for developing various adult metabolic diseases such as diabetes mellitus and coronary heart diseases; it has also been associated with higher incidences of complicated births. This study aimed to examine the predictability of macrosomic births in hyperglycemic pregnant women using maternal clinical characteristics and serum biomarkers of aneuploidy screening performed in the first half of pregnancy. Methods: A retrospective observational study was performed on a cohort of 1,668 pregnant women who 1) had positive outcomes after undergoing 50-g oral glucose challenge test (OGCT) at two university-based hospitals and 2) underwent any one of the following maternal biomarker screening tests for fetal aneuploidy: triple test, quadruple test, and integrated test. Logistic regression-based models for predicting macrosomic births using maternal characteristics and serum biomarkers were developed and evaluated for prediction power. A nomogram, which is a graphical display of the best predictable model, was then generated. Results: The study cohort included 157 macrosomic birth cases defined as birth weight ≥3,820 g, which was equivalent to the top 10 percentile of the modeling cohort. Three primary models solely based on serum biomarkers achieved area under curves (AUCs) of 0.55-0.62. Expanded models, including maternal demographic and clinical factors, demonstrated an improved performance by 25% (AUCs, 0.69-0.73). Conclusion: Our prediction models will help to identify pregnancies with an elevated risk of macrosomic births in hyperglycemic mothers using maternal clinical factors and serum markers from routine antenatal screening tests. Prediction of macrosomic birth at mid-pregnancy may allow customized antenatal care to reduce the risk of macrosomic births.

Higher Peripheral Cholesterol and a Positive Correlation With Risk for Large-For-Gestational-Age Neonates in Pre-Pregnancy Underweight Women

OBJECTIVE

As the high proportion of underweight pregnant women, omission of their weight gain and blood lipids management during gestation might lead to adverse pregnancy outcomes. This study aimed to determine the relationship between lipid profile and risks for adverse pregnancy outcomes in pre-pregnancy underweight women.

METHODS

This study was part of an ongoing cohort study including Chinese gravidas delivered from January 2015 to December 2016. Included subjects were grouped into underweight, normal-weight, and overweight by BMI before conception. Logistic regression was used to assess the association between lipid profiles during second trimester and adverse obstetric outcomes in each group. A subgroup analysis according to the gestational weight gain, in which subjects in each group were divided into above and within the Institute of Medicine (IOM) recommendations, was performed.

RESULTS

A total of 6, 223 women were included. The proportion of underweight (19.3%) was similar to that of overweight women (19.4%) in South China. Peripheral total cholesterol (TC) level in underweight women was significantly higher than that in overweight women (P <0.001). After adjusting maternal age, TC level was positively correlated to the risk for large-for-gestational-age (LGA) [aOR =2.24, 95%CI (1.08, 4.63)], and negatively related to the risk for small-for-gestational age (SGA) [aOR =0.71, 95%CI (0.59, 0.85)] in underweight women, but not in normal-weight or overweight women. The subgroup analysis showed that maternal TC level was positively correlated with the risk of LGA only in underweight women who gained weight more than the IOM recommendations.

CONCLUSION

Underweight pregnant women with high TC levels had a higher risk for LGA, especially among women whose gestational weight gain were above the IOM recommendations. Therefore, clinical management of lipids and weight gain during gestation should also be recommended for underweight women.

Maternal cholesterol levels during gestation: boon or bane for the offspring?

An increase in cholesterol levels is perceived during pregnancy and is considered as a normal adaptive response to the development of the fetus. In some pregnancies, excessive increase in total cholesterol with high levels of Low-Density Lipoprotein leads to maladaptation by the fetus to cholesterol demands, resulting in a pathological condition termed as maternal hypercholesterolemia (MH). MH is considered clinically irrelevant and therefore cholesterol levels are not routinely checked during pregnancy, as a consequence of which there is scarce information on its global prevalence in pregnant women. Studies have reported that MH during pregnancy can cause atherogenesis in adults emphasizing the concept of in utero programming of fetus. Moreover, Gestational Diabetes Mellitus, obesity and Polycystic Ovary Syndrome are potential risk factors which strengthen combined pathologies in placenta and fetuses of mothers with MH. However, lack of conclusive evidence on cholesterol transport and underlying programming demand substantial research to develop population-based life style strategies for women in their childbearing years. The current review focuses on the mechanisms and outcomes of MH from existing epidemiological as well as experimental data and presents a detailed insight on this novel risk factor of cardiovascular diseases.

Maternal Glucose and LDL-Cholesterol Levels Are Related to Placental Leptin Gene Methylation, and, Together With Nutritional Factors, Largely Explain a Higher Methylation Level Among Ethnic South Asians

BACKGROUND

Leptin, mainly secreted by fat cells, plays a core role in the regulation of appetite and body weight, and has been proposed as a mediator of metabolic programming. During pregnancy leptin is also secreted by the placenta, as well as being a key regulatory cytokine for the development, homeostatic regulation and nutrient transport within the placenta. South Asians have a high burden of type 2 diabetes, partly attributed to a "thin-fat-phenotype".

OBJECTIVE

Our aim was to investigate how maternal ethnicity, adiposity and glucose- and lipid/cholesterol levels in pregnancy are related to placental leptin gene (LEP) DNA methylation.

METHODS

We performed DNA methylation analyses of 13 placental LEP CpG sites in 40 ethnic Europeans and 40 ethnic South Asians participating in the STORK-Groruddalen cohort.

RESULTS

South Asian ethnicity and gestational diabetes (GDM) were associated with higher placental LEP methylation. The largest ethnic difference was found for CpG11 [5.8% (95% CI: 2.4, 9.2), p<0.001], and the strongest associations with GDM was seen for CpG5 [5.2% (1.4, 9.0), p=0.008]. Higher maternal LDL-cholesterol was associated with lower placental LEP methylation, in particular for CpG11 [-3.6% (-5.5, -1.4) per one mmol/L increase in LDL, p<0.001]. After adjustments, including for nutritional factors involved in the one-carbon-metabolism cycle (vitamin D, B12 and folate levels), ethnic differences in placental LEP methylation were strongly attenuated, while associations with glucose and LDL-cholesterol persisted.

CONCLUSIONS

Maternal glucose and lipid metabolism is related to placental LEP methylation, whilst metabolic and nutritional factors largely explain a higher methylation level among ethnic South Asians.

RANK links thymic regulatory T cells to fetal loss and gestational diabetes in pregnancy

Successful pregnancies rely on adaptations within the mother1, including marked changes within the immune system2. It has long been known that the thymus, the central lymphoid organ, changes markedly during pregnancy3. However, the molecular basis and importance of this process remain largely obscure. Here we show that the osteoclast differentiation receptor RANK4,5 couples female sex hormones to the rewiring of the thymus during pregnancy. Genetic deletion of Rank (also known as Tnfrsf11a) in thymic epithelial cells results in impaired thymic involution and blunted expansion of natural regulatory T (Treg) cells in pregnant female mice. Sex hormones, in particular progesterone, drive the development of thymic Treg cells through RANK in a manner that depends on AIRE+ medullary thymic epithelial cells. The depletion of Rank in the mouse thymic epithelium results in reduced accumulation of natural Treg cells in the placenta, and an increase in the number of miscarriages. Thymic deletion of Rank also results in impaired accumulation of Treg cells in visceral adipose tissue, and is associated with enlarged adipocyte size, tissue inflammation, enhanced maternal glucose intolerance, fetal macrosomia, and a long-lasting transgenerational alteration in glucose homeostasis, which are all key hallmarks of gestational diabetes. Transplantation of Treg cells rescued fetal loss, maternal glucose intolerance and fetal macrosomia. In human pregnancies, we found that gestational diabetes also correlates with a reduced number of Treg cells in the placenta. Our findings show that RANK promotes the hormone-mediated development of thymic Treg cells during pregnancy, and expand the functional role of maternal Treg cells to the development of gestational diabetes and the transgenerational metabolic rewiring of glucose homeostasis.

Gender-Specific Independent and Combined Effects of the Progesterone and 17-Hydroxyprogesterone on Metabolic Syndrome: From the Henan Rural Cohort Study

BACKGROUND

Although the concentrations of progesterone (P4) and 17-hydroxyprogesterone (17-OHP) have been correlated with some characteristics of metabolic syndrome (MetS), the relationships with MetS are inconclusive. Therefore, we investigated the relationship between P4 and 17-OHP with MetS.

METHODS

In all, the present study includes 4807 participants. Serum P4 and 17-OHP were measured through liquid chromatography-tandem mass spectrometry. Logistic regression and restricted cubic splines were used to assess the independent and combined effects of P4 and 17-OHP on MetS.

RESULTS

After adjusting for multiple variables, the positive association of P4 with MetS was observed in postmenopausal women (Third tertiles vs First tertiles: OR = 1.49, 95% CI: 1.20-1.86) and the negative association of 17-OHP with MetS was observed in men (Third tertiles vs First tertiles: OR = 0.43, 95% CI: 0.32-0.58). Compared with the combination of low P4 and low 17-OHP, the combination of high P4 and high 17-OHP were significantly related to MetS in postmenopausal women (OR = 1.71, 95% CI: 1.18-2.48). Moreover, the combination of low P4 and high 17-OHP was negatively associated with MetS in men (OR = 0.41, 95% CI: 0.24-0.69).

CONCLUSION

The association between P4 and MetS in postmenopausal women was positive, whereas 17-OHP was negatively associated with MetS in men. Additionally, their combination has a synergistic effect on MetS in postmenopausal women and an antagonistic effect on MetS in men.

Association of sugar-sweetened beverage intake with maternal postpartum weight retention

OBJECTIVE

During the perinatal period, modifiable behaviours contributing to excess weight gain, including sugar-sweetened beverage (SSB) intake, are understudied. We examined the extent to which perinatal SSB intake affects postpartum weight retention (PPWR).

DESIGN

We measured SSB intake frequency in the third trimester and 1-month postpartum using the NHANES Dietary Screener Questionnaire. We assessed the association between SSB intake and PPWR (difference between 6-month postpartum and pregravid weight) using multivariable regression adjusted for socio-demographic and anthropometric variables.

SETTING

Greater Boston area.

PARTICIPANTS

Three hundred forty-eight mother-infant pairs in the Rise and SHINE prospective birth cohort.

RESULTS

Mean age was 32·7 (sd 5·0) years; the sample was 47 % white, 32 % Hispanic, 14 % Asian and 7 % Black. Women reported mean daily SSB intake frequencies of 0·9 (sd 1·2) and 0·7 (sd 1·0) times/d in the third trimester and 1-month postpartum, respectively. At 6-month postpartum, average weight retention was 3·4 (sd 5·7) kg; 108 (sd 31 %) women had substantial PPWR, defined as a ≥ 5 kg increase between pregravid and 6-month postpartum weight. Each 1-time/d increment in SSB intake frequency during the third trimester (β = 0·46 kg (95 % CI, 0·07, 0·86)) and 1-month postpartum (β = 0·52 kg (95 % CI 0·03, 1·00)) was associated with higher weight retention at 6 months. Increased SSB intake frequency in the third trimester (OR: 1·37; 95 % CI 1·10, 1·75) and 1-month postpartum (OR: 1·17; 95 % CI 0·92, 1·52) resulted in higher odds of substantial PPWR.

CONCLUSIONS

SSB consumption during the perinatal period is associated with higher weight retention at 6-month postpartum. Avoiding SSB may reduce the risk of excess weight retention.

Associations between preconception macronutrient intake and birth weight across strata of maternal BMI

INTRODUCTION

Maternal nutrition during pregnancy is linked with birth outcomes including fetal growth, birth weight, congenital anomalies and long-term health through intra-uterine programming. However, a woman's nutritional status before pregnancy is a strong determinant in early embryo-placental development, and subsequently outcomes for both mother and child. Therefore, the aim of this study was to investigate the association between dietary macronutrient intake in the preconception period with birth weight.

METHODS

We studied a group of 1698 women from the Dutch Perined-Lifelines linked birth cohort with reliable detailed information on preconception dietary macronutrient intake (using a semi quantitative food frequency questionnaire) and data available on birth weight of the offspring. Birth weight was converted into gestational age adjusted z-scores, and macronutrient intake was adjusted for total energy intake using the nutrient residual method. Preconception BMI was converted into cohort-based quintiles. Multivariable linear regression was performed, adjusted for other macronutrients and covariates.

RESULTS

Mean maternal age was 29.5 years (SD 3.9), preconception BMI: 24.7 kg/m2 (SD 4.2) and median daily energy intake was 1812 kcal (IQR 1544-2140). Mean birth weight was 3578 grams (SD 472). When adjusted for covariates, a significant association (adjusted z score [95% CI], P) between polysaccharides and birth weight was shown (0.08 [0.01-0.15], 0.03). When linear regression analyses were performed within cohort-based quintiles of maternal BMI, positive significant associations between total protein, animal protein, fat, total carbohydrates, mono-disaccharides and polysaccharides with birth weight were shown in the lowest quintile of BMI independent of energy intake, intake of other macronutrients and covariates.

CONCLUSION

Out of all macronutrients studied, polysaccharides showed the strongest association with birth weight, independent of energy intake and other covariates. Our study might suggest that specifically in women with low preconception BMI a larger amount of macronutrient intake was associated with increased birth weight. We recommend that any dietary assessment and advise during preconception should be customized to preconception weight status of the women.

Nutrition and Metabolic Adaptations in Physiological and Complicated Pregnancy: Focus on Obesity and Gestational Diabetes

Pregnancy offers a window of opportunity to program the future health of both mothers and offspring. During gestation, women experience a series of physical and metabolic modifications and adaptations, which aim to protect the fetus development and are closely related to both pre-gestational nutritional status and gestational weight gain. Moreover, pre-gestational obesity represents a challenge of treatment, and nowadays there are new evidence as regard its management, especially the adequate weight gain. Recent evidence has highlighted the determinant role of nutritional status and maternal diet on both pregnancy outcomes and long-term risk of chronic diseases, through a transgenerational flow, conceptualized by the Development Origin of Health and Diseases (Dohad) theory. In this review we will analyse the physiological and endocrine adaptation in pregnancy, and the metabolic complications, thus the focal points for nutritional and therapeutic strategies that we must early implement, virtually before conception, to safeguard the health of both mother and progeny. We will summarize the current nutritional recommendations and the use of nutraceuticals in pregnancy, with a focus on the management of pregnancy complicated by obesity and hyperglycemia, assessing the most recent evidence about the effects of ante-natal nutrition on the long-term, on either maternal health or metabolic risk of the offspring.

Energetics at the urban edge: Environmental and individual predictors of urinary C-peptide levels in wild chacma baboons (Papio ursinus)

As human-modified landscapes encroach into natural habitats, wildlife face a reduction in natural food sources but also gain access to calorie-rich, human-derived foods. However, research into the energetics of wildlife living within and adjacent to urban and rural landscapes is lacking. C-peptide - a proxy for insulin production and a diagnostic tool for assessing pancreatic function in humans and domestic animals - can be quantified non-invasively from urine (uCP) and may provide a way to investigate the energetic correlates of living in human-altered landscapes. UCP is increasingly used in studies of primate energetics, and here we examine predictors of variation in uCP levels in n = 17 wild chacma baboons (Papio ursinus) living at the urban edge on the Cape Peninsula, South Africa. We find that uCP was positively associated with food provisioning and negatively with night fasting. UCP levels were comparable between winter and summer but significantly lower during spring, possibly driven by consumption of energy-rich seeds during summer and more human-derived foods during winter. UCP was elevated in pregnant females and similar for lactating and cycling females. We find no effect of dominance rank on uCP. Samples collected with synthetic Salivettes had significantly lower uCP levels than directly pipetted samples. Overall, our results indicate that uCP is a reliable, non-invasive measure of energy balance and intake in baboons, and suggest potential energetic benefits of living at the urban edge. More broadly, studies of uCP may offer unique insight into the environmental control of hormone-behaviour relationships in species crossing natural and urban environments.

CTRP-1 levels are related to insulin resistance in pregnancy and gestational diabetes mellitus

Recent studies have shown higher levels of CTRP-1 (C1QTNF-related protein) in patients with type 2 diabetes compared to controls. We aimed at investigating CTRP-1 in gestational diabetes mellitus (GDM). CTRP-1 levels were investigated in 167 women (93 with normal glucose tolerance (NGT), 74 GDM) of a high-risk population for GDM. GDM was further divided into GDM subtypes depending on a predominant insulin sensitivity issue (GDM-IR) or secretion deficit (GDM-IS). Glucose tolerance was assessed with indices [Matsuda index, Stumvoll first phase index, insulin-secretion-sensitivity-index 2 (ISSI-2), area-under-the-curve (AUC) insulin, AUC glucose] derived from an oral glucose tolerance test (oGTT) performed at < 21 and 24–28 weeks of gestation. In pregnancy, CTRP-1 levels of GDM (76.86 ± 37.81 ng/ml) and NGT (82.2 ± 35.34 ng/ml; p = 0.104) were similar. However, GDM-IR women (65.18 ± 42.18 ng/ml) had significantly lower CTRP-1 levels compared to GDM-IS (85.10 ± 28.14 ng/ml; p = 0.009) and NGT (p = 0.006). CTRP-1 levels correlated negatively with weight, AUC insulin, Stumvoll first phase index, bioavailable estradiol and positively with HbA1c, Matsuda Index and ISSI-2. A multiple regression analysis revealed bioavailable estradiol (β = − 0.280, p = 0.008) and HbA1c (β = 0.238; p = 0.018) as the main variables associated with CTRP-1 in GDM. Postpartum, waist and hip measurements were predictive of CRTP-1 levels instead. CTRP-1 levels were higher postpartum than during pregnancy (91.92 ± 47.27 vs.82.44 ± 38.99 ng/ml; p = 0.013). CTRP-1 is related to insulin resistance in pregnancy and might be a metabolic biomarker for insulin resistance in GDM. CTRP-1 levels were significantly lower during pregnancy than postpartum, probably due to rising insulin resistance during pregnancy.

Lipid metabolism is altered in maternal, placental, and fetal tissues of ewes with small for gestational age fetuses†

Nutrient restriction (NR) has the potential to negatively impact birthweight, an indicator of neonatal survival and lifelong health. Those fetuses are termed as small for gestational age (SGA). Interestingly, there is a spectral phenotype of fetal growth rates in response to NR associated with changes in placental development, nutrient and waste transport, and lipid metabolism. A sheep model with a maternal diet, starting at Day 35, of 100% National Research Council (NRC) nutrient requirements (n = 8) or 50% NRC (n = 28) was used to assess alterations in fetuses designated NR SGA (n = 7) or NR NonSGA (n = 7) based on fetal weight at Day 135 of pregnancy. Allantoic fluid concentrations of triglycerides were greater in NR SGA fetuses than 100% NRC and NR NonSGA fetuses at Day 70 (P < 0.05). There was a negative correlation between allantoic fluid concentrations of triglycerides (R2 = 0.207) and bile acids (R2 = 0.179) on Day 70 and fetal weight at Day 135 for NR ewes (P < 0.05). Bile acids were more abundant in maternal and fetal blood for NR SGA compared to 100% NRC and NR NonSGA ewes (P < 0.05). Maternal blood concentrations of NEFAs increased in late pregnancy in NR NonSGA compared to NR SGA ewes (P < 0.05). Protein expression of fatty acid transporter SLC27A6 localized to placentomal maternal and fetal epithelia and decreased in Day 70 NR SGA compared to 100% NRC and NR NonSGA placentomes (P < 0.05). These results identify novel factors associated with an ability of placentae and fetuses in NR NonSGA ewes to adapt to, and overcome, nutritional hardship during pregnancy.

Prenatal Hyperglycemia Exposure and Cellular Stress, a Sugar-Coated View of Early Programming of Metabolic Diseases

Worldwide, the number of people with diabetes has quadrupled since 1980 reaching 422 million in 2014 (World Health Organization). This distressing rise in diabetes also affects pregnant women and thus, in regard to early programming of adult diseases, creates a vicious cycle of metabolic dysfunction passed from one generation to another. Metabolic diseases are complex and caused by the interplay between genetic and environmental factors. High-glucose exposure during in utero development, as observed with gestational diabetes mellitus (GDM), is an established risk factor for metabolic diseases. Despite intense efforts to better understand this phenomenon of early memory little is known about the molecular mechanisms associating early exposure to long-term diseases risk. However, evidence promotes glucose associated oxidative stress as one of the molecular mechanisms able to influence susceptibility to metabolic diseases. Thus, we decided here to further explore the relationship between early glucose exposure and cellular stress in the context of early development, and focus on the concept of glycemic memory, its consequences, and sexual dimorphic and epigenetic aspects.

Vitamins Modulate the Expression of Antioxidant Genes in Progesterone-Treated Pancreatic β Cells: Perspectives for Gestational Diabetes Management

Gestational diabetes (GD) is a condition defined as carbohydrate intolerance and hyperglycemia beginning in the second trimester of pregnancy, which overlaps with the progesterone exponential increase. Progesterone has been shown to cause pancreatic β-cell death by a mechanism dependent on the generation of reactive oxygen species and oxidative stress. Herein, we studied the effect of this hormone on the expression of 84 genes related to oxidative stress and oxidant defense in pancreatic RINm5F cell lineage. Cells were incubated with 0.1, 1.0, or 100 μM progesterone for 6 or 24 h, in the presence or absence of the vitamins E and C. Among the investigated genes, five of them had their expression increased, at least 2-fold, in two different concentrations independently of the time of incubation, or at the same concentration at the different time points, including those that encode for stearoyl-CoA desaturase 1 (Scd1), dual oxidase 1 (Duox1), glutathione peroxidase 6 (GPx6), heme oxygenase 1 (Hmox1), and heat shock protein a1a (Hspa1a). Vitamins E and C were able to increase, in progesterone-treated cells, the expression of genes with antioxidant function such as Hmox1, but decreased Scd1 expression, a gene with prooxidant function. At cytoplasmic level, progesterone positively modulated Hmox1 and Hspa1a content. These results suggest that the protein encoded by these genes might protect cells against progesterone induced-oxidative damage, opening perspectives to elucidate the molecular mechanism involved in progesterone action in GD, as well as for the development of antioxidant strategies for the prevention and treatment of this disease.

Maternal perceived discrimination and association with gestational diabetes

BACKGROUND

Maternal psychosocial stress, including experiences of discrimination, has been linked to adverse pregnancy outcomes. Perceived discrimination may activate the chronic stress response, the downstream effects of which include dysregulation of metabolic and immune systems. The effect of perceived discrimination on the development of gestational diabetes mellitus, a metabolic disorder of pregnancy, has not been evaluated.

OBJECTIVE

This study aimed to evaluate the association between perceived maternal discrimination and incidence of gestational diabetes mellitus.

STUDY DESIGN

A prospective cohort study of 744 pregnant women was conducted from 2013 to 2015 at 4 sites in the United States. Participants were women who were ≥18 years old with a singleton pregnancy, <21 weeks pregnant when recruited into the study, and English speaking without fetal anomalies, progesterone treatment, or corticosteroid use during pregnancy. Women with pregestational diabetes were excluded from the study. Participants with a gestational age between 12 0/7 and 20 6/7 weeks completed the Williams Discrimination Scale. For this analysis, Williams Discrimination Scale scores were dichotomized at the 75th percentile. We estimated the association between scoring in the top quartile of the Williams Discrimination Scale and developing gestational diabetes mellitus using logistic regression. As obesity is an independent risk factor for developing gestational diabetes mellitus, we also used mediation methods to determine the proportion of the association mediated by prepregnancy obesity (body mass index, ≥30 kg/m²). Models were adjusted for maternal age, income, parity, race and ethnicity, and study site.

RESULTS

Among the 595 eligible subjects, 368 (61.9%) were white, 99 (16.6%) black, and 93 (15.6%) Hispanic. The mean body mass index was 27.4 kg/m² (standard deviation, 7.1 kg/m²), and 50 subjects (8.4%) developed gestational diabetes mellitus. Women with gestational diabetes mellitus were significantly more likely to be older, to be multiparous, and to have a lower income. Scoring in the top quartile of the Williams Discrimination Scale was associated with a significantly increased risk of developing gestational diabetes mellitus (12.8% vs 7.0%; adjusted odds ratio, 2.11; 95% confidence interval, 1.03-4.22). Obesity mediated 22.6% of the relationship between the Williams Discrimination Scale and gestational diabetes mellitus.

CONCLUSION

Women who perceived greater discrimination had an increased risk of developing gestational diabetes mellitus. Results from the mediation analysis indicate that more than 20% of the association between discrimination and gestational diabetes mellitus operates via a pathway that includes obesity. Future studies should examine this and other mechanistic pathways that may underlie these associations.

Characterizing the Effects of Diabetes and Obesity on Insulin and Leptin Levels amongst Pregnant Women

OBJECTIVE

In this study, we assess the impact of obesity and diabetes on maternal brain and periphery, as well as fetal exposure to insulin and leptin, and two hormones that play an important role in regulating energy homeostasis.

STUDY DESIGN

Fasting maternal plasma, fetal cord vein and artery plasma, and maternal cerebrospinal fluid (CSF) were collected in 37 women (12 lean, nondiabetic [prepregnancy body mass index (BMI): 22.9 ± 1.7 kg/m²]; 12 overweight/obese nondiabetic [BMI: 37.8 ± 7.3 kg/m²]; 13 gestational/type 2 diabetes mellitus [BMI: 29.8 ± 7.3 kg/m²]) with uncomplicated singleton pregnancies undergoing elective Cesarean delivery. HbA1C, insulin, glucose, and leptin levels were measured.

RESULTS

Compared with lean mothers, mothers with obesity and diabetes mellitus (DM) had significantly lower CSF-to-plasma ratios of insulin. Moreover, mothers with obesity and DM had significantly lower cord arterial and cord venous to maternal plasma ratios of insulin, but not leptin, compared with lean mothers. There were no differences in CSF and cord blood insulin and leptin levels between obese and DM mothers.

CONCLUSION

Compared with lean individuals, mothers with obesity and DM have relative deficiencies in insulin exposure. The patterns observed in mothers with obesity and diabetes were similar highlighting the importance of the maternal metabolic environment in obesity and suggesting obese patients warrant further clinical focus.

Multidisciplinary approach in medicine: successful pregnancy in a patient with hyperinsulinism/hyperammonaemia (HI/HA) syndrome

This case illustrates the importance of multidisciplinary counselling and management of pregnancies in women with complex medical conditions, especially concerning women with cognitive impairment. We present a woman with hyperinsulinism/hyperammonaemia (HI/HA) syndrome. This syndrome is characterised by recurrent episodes of hypoglycaemia and elevated ammonia levels, which are potentially harmful to both the patient and a developing fetus. We describe a successful multidisciplinary approach during the pregnancy of a mentally challenged patient with HI/HA syndrome. This case illustrates the importance of personalised counselling during the preconception period and emphasises to include all disciplines involved in the medical and daily care of such a patient. In our case, the extensive multidisciplinary care during the preconception period, pregnancy, delivery and postpartum period resulted in a good maternal and neonatal outcome.

Anatomical and physiological alterations of pregnancy

The extensive metabolic demands of pregnancy require specific physiological and anatomical changes. These changes affect almost all organ systems, including the cardiovascular, respiratory, renal, gastrointestinal, and hematologic system. The placenta adds another layer of complexity. These changes make it challenging for clinicians to understand presenting signs and symptoms, or to interpret laboratory and radiological tests. Furthermore, these physiological alterations can affect the pharmacokinetics and pharmacodynamics of drugs. Drug safety in lactation is only supported by limited evidence. In addition, the teratogenic effects of medications are often extrapolated from animals, which further adds uncertainties. Unfortunately, pregnant women are only rarely included in clinical drug trials, while doses, regimens, and side effects are often extrapolated from studies conducted in non-pregnant populations. In this comprehensive review, we present the changes occurring in each system with its effects on the pharmacokinetic variables. Understanding these physiological changes throughout normal pregnancy helps clinicians to optimize the health of pregnant women and their fetuses. Furthermore, the information on pregnancy-related physiology is also critical to guide study design in this vulnerable 'orphan' population, and provides a framework to explore pregnancy-related pathophysiology such as pre-eclampsia.

Effects of a modestly lower carbohydrate diet in gestational diabetes: a randomized controlled trial

BACKGROUND

Lower carbohydrate diets have the potential to improve glycemia but may increase ketonemia in women with gestational diabetes (GDM). We hypothesized that modestly lower carbohydrate intake would not increase ketonemia.

OBJECTIVE

To compare blood ketone concentration, risk of ketonemia, and pregnancy outcomes in women with GDM randomly assigned to a lower carbohydrate diet or routine care.

METHODS

Forty-six women aged (mean ± SEM) 33.3 ± 0.6 y and prepregnancy BMI 26.8 ± 0.9 kg/m2 were randomly assigned at 28.5 ± 0.4 wk to a modestly lower carbohydrate diet (MLC, ∼135 g/d carbohydrate) or routine care (RC, ∼200 g/d) for 6 wk. Blood ketones were ascertained by finger prick test strips and 3-d food diaries were collected at baseline and end of the intervention.

RESULTS

There were no detectable differences in blood ketones between completers in the MLC group compared with the RC group (0.1 ± 0.0 compared with 0.1 ± 0.0 mmol/L, n = 33, P = 0.31, respectively), even though carbohydrate and total energy intake were significantly lower in the intervention group (carbohydrate 165 ± 7 compared with 190 ± 9 g, P = 0.04; energy 7040 ± 240 compared with 8230 ± 320 kJ, P <0.01, respectively). Only 20% of participants in the MLC group met the target intake compared with 65% in the RC group (P <0.01). There were no differences in birth weight, rate of large-for-gestational-age infants, percent fat mass, or fat-free mass between groups.

CONCLUSIONS

An intervention to reduce carbohydrate intake in GDM did not raise ketones to clinical significance, possibly because the target of 135 g/d was difficult to achieve in pregnancy. Feeding studies with food provision may be needed to assess the benefits and risks of low-carbohydrate diets. This trial was registered at www.anzctr.org.au as ACTRN12616000018415.

Secretagogin is Related to Insulin Secretion but Unrelated to Gestational Diabetes Mellitus Status in Pregnancy

Secretagogin (SCGN) is a calcium binding protein related to insulin release in the pancreas. Although SCGN is not co-released with insulin, plasma concentrations have been found to be increased in type 2 diabetes mellitus patients. Until now, no study on SCGN levels in pregnancy or patients with gestational diabetes mellitus (GDM) has been published. In 93 women of a high-risk population for GDM at the Medical University of Vienna, secretagogin levels of 45 GDM patients were compared to 48 women with a normal glucose tolerance (NGT). Glucose tolerance, insulin resistance and secretion were assessed with oral glucose tolerance tests (OGTT) between the 10th and 28th week of gestation (GW) and postpartum. In all women, however, predominantly in women with NGT, there was a significant positive correlation between SCGN levels and Stumvoll first (r_p = 0.220, p = 0.032) and second phase index (r_p = 0.224, p = 0.028). SCGN levels were not significantly different in women with NGT and GDM. However, SCGN was higher postpartum than during pregnancy (postpartum: 88.07 ± 35.63 pg/mL; pregnancy: 75.24 ± 37.90 pg/mL, p = 0.004). SCGN was directly correlated with week of gestation (r_p = 0.308; p = 0.021) and triglycerides (r_p = 0.276; p = 0.038) in women with GDM. Therefore, SCGN is related to insulin secretion and hyperinsulinemia during pregnancy; however, it does not display differences between women with NGT and GDM.