Metformin in gestational diabetes: the offspring follow-up (MiG TOFU): body composition at 2 years of age

A cautionary response to SMFM statement: pharmacological treatment of gestational diabetes

Use of oral agents to treat gestational diabetes mellitus remains controversial. Recent recommendations from the Society for Maternal-Fetal Medicine assert that metformin may be a safe first-line alternative to insulin for gestational diabetes mellitus treatment and preferable to glyburide. However, several issues should give pause to the widespread adoption of metformin use during pregnancy. Fetal concentrations of metformin are equal to maternal, and metformin can inhibit growth, suppress mitochondrial respiration, have epigenetic modifications on gene expression, mimic fetal nutrient restriction, and alter postnatal gluconeogenic responses. Because both the placenta and fetus express metformin transporters and exhibit high mitochondrial activity, these properties raise important questions about developmental programming of metabolic disease in offspring. Animal studies have demonstrated that prenatal metformin exposure results in adverse long-term outcomes on body weight and metabolism. Two recent clinical randomized controlled trials in women with gestational diabetes mellitus or polycystic ovary syndrome provide evidence that metformin exposure in utero may produce a metabolic phenotype that increases childhood weight or obesity. These developmental programming effects challenge the conclusion that metformin is equivalent to insulin. Although the Society for Maternal-Fetal Medicine statement endorsed metformin over glyburide if oral agents are used, there are few studies directly comparing the 2 agents and it is not clear that metformin alone is superior to glyburide. Moreover, it should be noted that prior clinical studies have dosed glyburide in a manner inconsistent with its pharmacokinetic properties, resulting in poor glycemic control and high rates of maternal hypoglycemia. We concur with the American Diabetes Association and American Congress of Obstetricians and Gynecologists, which recommend insulin as the preferred agent, but we believe that it is premature to embrace metformin as equivalent to insulin or superior to glyburide. Due to the uncertainty of the long-term metabolic risks of either metformin or glyburide, we call for carefully controlled studies that optimize oral medication dosing according to their pharmacodynamic and pharmacokinetic properties in pregnancy, appropriately target medications based on individual patterns of hyperglycemia, and follow the offspring long-term for metabolic risk.

Long-Term Effects of Oral Antidiabetic Drugs During Pregnancy on Offspring: A Systematic Review and Meta-analysis of Follow-up Studies of RCTs

INTRODUCTION

Antidiabetic drugs (OADs) are increasingly prescribed to treat hyperglycaemia during pregnancy in women with gestational diabetes mellitus (GDM) or polycystic ovary syndrome (PCOS), even though long-term effects on offspring are unknown. This systematic review summarises the evidence of follow-up studies of randomised controlled trials (RCTs) reporting on long-term effects of prenatal exposure to OADs on offspring.

METHODS

The MEDLINE, EMBASE and CENTRAL databases were searched from inception to April 2018 for the concepts antidiabetic agents and prenatal exposure (or pregnancy and offspring/child) in combination with an RCT search filter. RCTs evaluating post-neonatal health effects in offspring and comparing maternal treatment with an OAD with no treatment, placebo, an alternative OAD or insulin during pregnancy were eligible for inclusion. Two independent researchers selected, extracted and assessed the data. Meta-analyses were performed using a random effects model and the Cochrane Collaboration's risk of bias tool was used for quality assessment.

RESULTS

Ten studies were included, with a maximal follow-up duration of 9 years, comprising 778 children of mothers with GDM or PCOS who were randomised to either metformin or insulin/placebo during pregnancy. Meta-analysis showed that children prenatally exposed to metformin were heavier compared to controls (standardised mean difference (SMD) 0.26 [95% CI 0.11-0.41]), but not taller (SMD 0.10 [95% CI -0.14-0.33]). Additionally, offspring body mass index (BMI) z scores did not differ according to metformin exposure (mean difference 0.30 [95% CI -0.01-0.61]). Individual small studies reported that prenatal exposure to metformin was associated with greater mid-upper arm, head and waist circumferences, biceps skinfolds, waist-to-height ratio, more arm fat, higher fasting glucose, ferritin and lower LDL cholesterol in offspring.

CONCLUSION

Prenatal exposure to metformin is associated with increased offspring weight, but not with height or BMI. Larger follow-up studies are needed to confirm and look into the implications of these findings. Plain language summary available for this article.

Oral Agents for the Treatment of Gestational Diabetes

PURPOSE OF REVIEW

To review the current evidence of the safety and efficacy of the use of oral agents for treatment of gestational diabetes (GDM).

RECENT FINDINGS

The use of metformin and glyburide in pregnancy for treatment of GDM has dramatically increased since the early 2000s. Meta-analyses suggest that glyburide may increase the risk for large for gestational (LGA) infants and neonatal hypoglycemia. Conversely, metformin may potentially decrease rates of pregnancy-induced hypertension, LGA, neonatal hypoglycemia, and maternal weight gain. However, recent long-term offspring studies indicate a potential detrimental effect of metformin on fat mass that suggests an effect of such medication on fetal programming. While there have been several novel oral anti-diabetes medications brought to market in the past decade, there is minimal data to guide use and in particular data regarding long-term safety for the exposed offspring of treated women. Most professional societies recommend insulin as first-line treatment of gestational diabetes after failure of lifestyle modification. Both metformin and glyburide cross the placenta and long-term safety data is limited. However, patient satisfaction is substantially higher with use of oral agents, and the current literatures suggest that metformin may reduce several common short-term adverse outcomes related to GDM.

Gestational Diabetes: Underpinning Principles, Surveillance, and Management

Gestational diabetes mellitus (GDM) is carbohydrate intolerance resulting in hyperglycemia with onset during pregnancy. The article aims to provide clinicians with a working framework to minimize maternal and neonatal morbidity. Landmark historical and recent data are reviewed and presented to provide clinicians with a quick, easy reference for recognition and management of GDM. Data presented tie in insights with underlying pathophysiologic processes leading to GDM. Screening and diagnostic thresholds are discussed along with management upon diagnosis. Good clinical practice regarding screening, diagnosis, and management of GDM effectively reduces risk and improves outcomes of women and fetuses in affected pregnancies.

Pregestational Diabetes in Pregnancy

Diabetes is a common chronic condition in women of reproductive age. Preconception care is crucial to reducing the risk of adverse maternal and fetal outcomes, such as hypertensive disorders, abnormal fetal growth, traumatic delivery and stillbirth, associated with poor glycemic control. Insulin is the preferred medication to optimize glucose control in women with pregestational diabetes. Frequent dose adjustments are needed during pregnancy to achieve glycemic goals, and team-based multidisciplinary care may help. Postpartum care should include lactation support, counseling on contraceptive options, and transition to primary care.

Gestational diabetes mellitus: Multi-disciplinary treatment approaches

Gestational diabetes mellitus (GDM) is the most common metabolic disease of pregnancy, associated with several perinatal complications. Adequate glycemic control has been proved to decrease risk of GDM-related complications. Several studies have shown the beneficial effect of exercise and medical nutrition treatment on glycemic and weight control in GDM-affected women. Moreover, pharmacological agents, such as insulin and specific oral anti-diabetic agents can be prescribed safely during pregnancy, decreasing maternal blood glucose and, thus, perinatal adverse outcomes. Multi-disciplinary treatment approaches that include both lifestyle modifications (medical nutritional therapy and daily physical exercise) and pharmacological treatment, in cases of failure of the former, constitute the most effective approach. Insulin is the gold standard pharmacological agent for GDM treatment. Metformin and glyburide are two oral anti-diabetic agents that could serve as alternative, although not equal in terms of effectiveness and safety, treatment for GDM. As studies on short-term safety of metformin are reassuring, in some countries it is considered as first-line treatment for GDM management. More studies are needed to investigate the long-term effects on offspring. As safety issues have been raised on the use of glyburide during pregnancy, it must be used only when benefits surpass possible risks.

Pharmacotherapy for gestational diabetes

INTRODUCTION

Gestational diabetes mellitus (GDM) represents impaired carbohydrate metabolism during pregnancy and is characterized by progressive insulin resistance and compensatory hyperinsulinaemia. If inadequately treated, it may lead to fetal macrosomia and other adverse outcomes.

AREAS COVERED

In this review, the authors summarize the current evidence from studies on the use of insulin and other agents for the treatment of women with GDM.

EXPERT OPINION

Lifestyle management is of paramount importance for the treatment of GDM. In pharmacotherapy, insulin remains the long-established mainstay of treatment. NPH (Neutral Protamine Hagedorn) and soluble human insulin have long been established for use, but favorable experience has now also accumulated with the newer insulins (aspart, lispro, detemir). Alternatively, metformin and glyburide have been used in GDM, but they have never gained wide acceptance. Nutritional supplements based on micronutrients and bioactives (probiotics and myoinositol) have shown promising results as well. Further experience with incretin agents (DPP-4 inhibitors and GLP-1 receptor agonists) is awaited.

Changing environment of hyperglycemia in pregnancy: Gestational diabetes and diabetes mellitus in pregnancy

The diagnosis and treatment of gestational diabetes mellitus (GDM) have been in a state of flux since the World Health Organization accepted and endorsed the International Diabetes and Pregnancy Study Group's diagnostic pathway and criteria in 2013. These new diagnostic criteria identify an increasing number of women at risk of hyperglycemia in pregnancy (HGiP). Maternal hyperglycemia represents a significant risk to the mother and fetus, in both the short and long term. Controversially, metformin use for the treatment of GDM is increasing in Australia. This article identifies the multiple and varied presentations of HGiP, of which GDM is the most commonly encountered. The degree of maternal hyperglycemia experienced affects the outcomes for both the mother and neonate, and specific diagnosis determines the appropriate treatment for the pregnancy. Given the increasing incidence of women with dysglycemia and those developing HGiP, this is an important area for research and clinical attention for all health professionals.

Targeted Multiplex Gene Expression Profiling to Measure High-Fat Diet and Metformin Effects on Fetal Gene Expression in a Mouse Model

BACKGROUND

Maternal obesity and excessive gestational weight gain (GWG) are associated with delivery of a large-for-gestational-age infant. We used a high-fat diet (HFD) mouse model to separate the effect of maternal obesity from excessive GWG on fetal growth. Our objective was to identify fetal gene expression changes in an HFD and control diet (CD) mouse model with and without metformin exposure.

STUDY DESIGN

Normal weight timed-pregnant (Female Friend virus B) strain mice were allocated on day e0.5 to receive HFD or CD and either plain water or metformin (2.5 mg/mL in drinking water). Dams were euthanized on day e17.5 and fetal livers harvested and frozen at -80°C. RNA was extracted and hybridized to a customized 96-gene Nanostring panel focused on angiogenesis, inflammation, and growth gene expression. Fetal liver gene expression was compared between metformin and plain water groups using analysis of variance. Significant differences in gene expression, defined by a false discovery controlled q value <0.01, were then analyzed using Ingenuity pathway analysis (IPA).

RESULTS

In HFD-fed dams, compared to controls, the metformin-treated group had significantly lower fetal weight and 39 differentially expressed liver genes; 15 (38%) were in the growth/angiogenesis gene expression network. IPA predicted that fetal liver gene upregulation associated with metformin exposure is a result of metformin inhibition of the common upstream regulator, phosphatase and tensin homolog ( PTEN).

CONCLUSIONS

Metformin-exposed fetuses from dams fed HFD and CD have significant gene expression differences in genes specific to growth and angiogenesis pathways in the fetal liver. Diet alone did not alter fetal liver gene expression.

Metformin in Pregnancy: Mechanisms and Clinical Applications

Metformin use in pregnancy is increasing worldwide as randomised controlled trial (RCT) evidence is emerging demonstrating its safety and efficacy. The Metformin in Gestational Diabetes (MiG) RCT changed practice in many countries demonstrating that metformin had similar pregnancy outcomes to insulin therapy with less maternal weight gain and a high degree of patient acceptability. A multicentre RCT is currently assessing the addition of metformin to insulin in pregnant women with type 2 diabetes. RCT evidence is also available for the use of metformin in pregnancy for women with Polycystic Ovarian Syndrome and for nondiabetic women with obesity. No evidence of an increase in congenital malformations or miscarriages has been observed even when metformin is started before pregnancy and continued to term. Body composition and metabolic outcomes at two, seven, and nine years have now been reported for the offspring of mothers treated in the MiG study. In this review, we will briefly discuss the action of metformin and then consider the evidence from the key clinical trials.

Metformin or insulin: logical treatment in women with gestational diabetes in the Middle East, our experience

OBJECTIVE

The debate still continues about the preferred modality of treatment of gestational diabetes requiring pharmacological treatment. Insulin was previously considered as the gold standard, but the National Institute of Health and Care Excellence now recommend metformin as the first line drug of choice. The pharmacological management of gestational diabetes mellitus in the Middle East with its high risk population has not been widely published. We aim to evaluate the safety and efficacy of using metformin in comparison to insulin, in our group of patients, and to study key associated morbidities.

RESULTS

A total of 291 women registered in the clinic during the study period. One hundred and twenty-one (121) were women with gestational diabetes Mellitus requiring medical therapy. Among them, 107 delivered at term. Ninety (84%) women received metformin. Additional insulin was required in 32% of these patients. There was a significant difference in the birth weight of babies in the metformin with insulin group of 207 g (p value 0.04) in favour of metformin. There was no significant difference in maternal or neonatal morbidities between the groups. Metformin was thus found to be a safe, practical and cost effective medication to be offered to our population.

Epigenetic effects of metformin: From molecular mechanisms to clinical implications

There is a growing body of evidence that links epigenetic modifications to type 2 diabetes. Researchers have more recently investigated effects of commonly used medications, including those prescribed for diabetes, on epigenetic processes. This work reviews the influence of the widely used antidiabetic drug metformin on epigenomics, microRNA levels and subsequent gene expression, and potential clinical implications. Metformin may influence the activity of numerous epigenetic modifying enzymes, mostly by modulating the activation of AMP-activated protein kinase (AMPK). Activated AMPK can phosphorylate numerous substrates, including epigenetic enzymes such as histone acetyltransferases (HATs), class II histone deacetylases (HDACs) and DNA methyltransferases (DNMTs), usually resulting in their inhibition; however, HAT1 activity may be increased. Metformin has also been reported to decrease expression of multiple histone methyltransferases, to increase the activity of the class III HDAC SIRT1 and to decrease the influence of DNMT inhibitors. There is evidence that these alterations influence the epigenome and gene expression, and may contribute to the antidiabetic properties of metformin and, potentially, may protect against cancer, cardiovascular disease, cognitive decline and aging. The expression levels of numerous microRNAs are also reportedly influenced by metformin treatment and may confer antidiabetic and anticancer activities. However, as the reported effects of metformin on epigenetic enzymes act to both increase and decrease histone acetylation, histone and DNA methylation, and gene expression, a significant degree of uncertainty exists concerning the overall effect of metformin on the epigenome, on gene expression, and on the subsequent effect on the health of metformin users.

Metformin exposure in first trimester of pregnancy and risk of all or specific congenital anomalies: exploratory case-control study

OBJECTIVE

To investigate whether exposure to metformin during the first trimester of pregnancy, for diabetes or other indications, increases the risk of all or specific congenital anomalies.

DESIGN

Population based exploratory case-control study using malformed controls. Cases of 29 specific subgroups of non-genetic anomalies, and all non-genetic anomalies combined, were compared with controls (all other non-genetic anomalies or genetic syndromes).

SETTING

11 EUROmediCAT European congenital anomaly registries surveying 1 892 482 births in Europe between 2006 and 2013.

PARTICIPANTS

50 167 babies affected by congenital anomaly (41 242 non-genetic and 8925 genetic) including live births, fetal deaths from 20 weeks' gestation, and terminations of pregnancy for fetal anomaly.

MAIN OUTCOME MEASURE

Odds ratios adjusted for maternal age, registry, multiple birth, and maternal diabetes status.

RESULTS

168 babies affected by congenital anomaly (141 non-genetic and 27 genetic) were exposed to metformin, 3.3 per 1000 births. No evidence was found for a higher proportion of exposure to metformin during the first trimester among babies with all non-genetic anomalies combined compared with genetic controls (adjusted odds ratio 0.84, 95% confidence interval 0.55 to 1.30). The only significant result was for pulmonary valve atresia (adjusted odds ratio 3.54, 1.05 to 12.00, compared with non-genetic controls; 2.86, 0.79 to 10.30, compared with genetic controls).

CONCLUSIONS

No evidence was found for an increased risk of all non-genetic congenital anomalies combined following exposure to metformin during the first trimester, and the one significant association was no more than would be expected by chance. Further surveillance is needed to increase sample size and follow up the cardiac signal, but these findings are reassuring given the increasing use of metformin in pregnancy.

Metformin in the management of diabetes during pregnancy and lactation

This review explores the current place of metformin in the management of gestational diabetes (GDM) and type 2 diabetes during pregnancy and lactation. The rationale and basic pharmacology of metformin usage in pregnancy is discussed along with the evidence from observational and randomized controlled trials in women with GDM or overt diabetes. There seems to be adequate evidence of efficacy and short-term safety of metformin in relation to maternal and neonatal outcomes in GDM, with possible benefits related to lower maternal weight gain and lower risk of neonatal hypoglycemia and macrosomia. Additionally, metformin offers the advantages of oral administration, convenience, less cost and greater acceptability. Metformin may, therefore, be considered in milder forms of GDM where glycemic goals are not attained by lifestyle modification. However, failure rate is likely to be higher in those with an earlier diagnosis of GDM, higher blood glucose, higher body mass index (BMI) or previous history of GDM, and insulin remains the cornerstone of pharmacological treatment in such cases. The use of metformin in type 2 diabetes has been assessed in observational and small randomized trials. Metformin monotherapy in women with overt diabetes is highly unlikely to achieve glycemic targets. Hence, the use should be restricted as adjunct to insulin and may be considered in women with high insulin dose requirements or rapid weight gain. There is clearly a need for more clinical trials to assess the effect of combined insulin plus metformin therapy in pregnancy with type 2 diabetes. Additionally, there is a paucity of data on long-term effects in offspring exposed to metformin in utero. It is imperative to further explore its impact on offspring as metformin has significant transplacental transfer and has the potential to impact the programming of the epigenome. Therefore, caution must be exercised when prescribing metformin in pregnant women. More research is clearly needed before metformin can be considered as standard of care in the management of diabetes during pregnancy.

Involvement of mTOR, JNK and PI3K in the negative effect of ethanol and metformin on the human first-trimester extravillous trophoblast HTR-8/SVneo cell line

Our aim was to investigate the effect of two xenobiotics to which pregnant woman may be exposed, the drug of abuse ethanol (EtOH) (and its metabolite acetaldehyde (ACA)) and the therapeutic agent metformin (METF), on placentation-related processes in an extravillous trophoblastic (EVTs) cell line (HTR-8/SVneo cells). EtOH, ACA and METF (24 h) significantly reduced cell proliferation rates, culture growth, viability and migratory capacity of HTR-8/SVneo cells. Moreover, both EtOH (100 μM) and METF (1 mM) increased the apoptosis index and inhibited ³H-deoxy-D-glucose (³H-DG) and ³H-folic acid (³H-FA) uptake. mTOR, JNK and PI3K intracellular signaling pathways were involved in the effect of EtOH upon ³H-FA uptake and in the effect of METF upon cell viability, and mTOR and JNK in the effect of EtOH upon cell viability and ³H-DG uptake. We show that EtOH and METF have a detrimental effect in placentation-related processes of HTR-8/SVneo cells. Moreover, mTOR, JNK and PI3K appear to mediate some of these negative effects.

Predictors of metformin failure in gestational diabetes mellitus (GDM)

INTRODUCTION AND OBJECTIVE

The role of metformin in gestational diabetes mellitus (GDM) is also increasing. However, almost half of metformin-treated women required additional insulin. Therefore, identifying the characteristics of these women may help define optimal therapeutic strategy.

METHODS

This is a retrospective cohort study done in a District General Hospital, UK. GDM was diagnosed by 75 g OGTT test between 24 and 28 weeks of gestation with fasting levels of ≥6.1 mmol/l and/or 2 h postprandial (PP) level of ≥7.8 mmol/l. Logistic regression and receiver operator curves (ROC) were performed to identify the predictors of metformin failure.

RESULTS

Out of 228 women with GDM included, 46/228 (20.2%) and 151/228 (66.2%) received insulin and metformin as first-line medication respectively. Among the metformin-treated, 13 stopped treatment and were excluded from analysis. Of the included 138 metformin-treated women, 77 (55.8%) required supplementary insulin (metformin failure). Metformin failure group had higher maternal age and fasting glucose level at OGTT, HbA1c at OGTT and earlier gestational age (GA) at medication initiation. Metformin failure was predicted if fasting OGTT level >4.8 mmol/l (69% sensitivity and 62% specificity). If the fasting levels of IADPSG (International Association of Diabetes and Pregnancy Study Groups) criteria and NICE (National Institute of Health and Care Excellence) were used, the positive predictive value was 78% and 77% respectively.

CONCLUSION

As women with higher fasting glucose levels have higher chance of necessitating insulin in later pregnancies, appropriate addition of insulin at metformin initiation for these women could help better glycaemic control throughout pregnancy.

Metformin treatment of type 2 diabetes mellitus in pregnancy: update on safety and efficacy

With the increasing prevalence of type 2 diabetes mellitus (T2DM) in women of childbearing age, prescribing antidiabetic medications in first-trimester pregnancy is becoming more common. Metformin treatment during this time is usually avoided in countries with well-resourced healthcare. This is based on historical concerns about safety to the foetus and the widespread availability of insulin. However, there is now increasing interest in the potential benefits of metformin in pregnant women with T2DM. In this commentary, the main evidence supporting metformin safety in pregnancy is summarized, with an emphasis on the first trimester. Based on a structured literature search, the recent randomized controlled trials comparing metformin and insulin are reviewed. We then show that prescribing advice for metformin in pregnancy is inconsistent and product information/package inserts (PI) are universally out of date. This causes confusion and pushes some women and their clinicians to change from metformin to insulin. The potential advantages of metformin in pregnant women with T2DM are then discussed, including oral dosing and improved acceptability, lower resource utilization and cost, decreased insulin requirements, less maternal weight gain and less risk of maternal and neonatal hypoglycaemia. The conclusion is that metformin is a cheap and efficacious antidiabetic medication for many pregnant women with T2DM, with reasonable evidence for safety. Drug information resources should be updated so that metformin can be considered more broadly in women with T2DM who present for antenatal care.

Developmental origins of health and disease: current knowledge and potential mechanisms

Epidemiologic and clinical research has provided a large body of evidence supporting the developmental origins of health and disease (DOHaD), but there has been a relative dearth of mechanistic studies in humans due to the complexity of working with large, longitudinal cohorts. Nonetheless, animal models of undernutrition have provided substantial evidence for the potential epigenetic, metabolic, and endocrine mechanisms behind DOHaD. Furthermore, recent research has explored the interaction between the environment and the gastrointestinal system by investigating how the gut microbial ecology may impact the capacity for nutrient processing and absorption in a manner that may limit growth. This review presents a summary of current research that supports the concept of DOHaD, as well as potential mechanisms and interactions that explain how nutrition in utero and during early childhood influences lifelong health.

Reduced Cortical Excitability, Neuroplasticity, and Salivary Cortisol in 11-13-Year-Old Children Born to Women with Gestational Diabetes Mellitus

Background

Children exposed to gestational diabetes mellitus (GDM) in utero are at increased risk of neurodevelopmental difficulties, including autism and impaired motor control. However, the underlying neurophysiology is unknown.

Methods

Using transcranial magnetic stimulation, we assessed cortical excitability, long-term depression (LTD)-like neuroplasticity in 45 GDM-exposed and 12 control children aged 11–13 years. Data were analysed against salivary cortisol and maternal diabetes severity and treatment (insulin [N = 22] or metformin [N = 23]) during pregnancy.

Findings

GDM-exposed children had reduced cortical excitability (p = .003), LTD-like neuroplasticity (p = .005), and salivary cortisol (p < .001) when compared with control children. Higher maternal insulin resistance (IR) before and during GDM treatment was associated with a blunted neuroplastic response in children (p = .014) and this was not accounted for by maternal BMI. Additional maternal and neonatal measures, including fasting plasma glucose and inflammatory markers, predicted neurophysiological outcomes. The metformin and insulin treatment groups had similar outcomes.

Interpretation

These results suggest that GDM can contribute to subtle differences in child neurophysiology, and possibly cortisol secretion, persisting into early adolescence. Importantly, these effects appear to occur during second trimester, before pharmacologic treatment typically commences, and can be predicted by maternal insulin resistance. Therefore, earlier detection and treatment of GDM may be warranted. Metformin appears to be safe for these aspects of neurodevelopment.

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Children exposed to gestational diabetes (GDM) had lower cortical excitability, measured as higher resting motor thresholds.

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The GDM group also exhibited smaller LTD-like neuroplastic responses to repetitive brain stimulation.

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These were associated with lower salivary cortisol and with maternal diabetes severity, especially insulin resistance.

Our results suggest that gestational diabetes, even when detected and treated as per clinical guidelines, has subtle effects on important neurophysiological processes persisting into early adolescence, including neuroplasticity and possibly cortisol secretion. The extent of these effects is related to the severity of maternal diabetes, particularly insulin resistance, during mid pregnancy. These results may aid in understanding how insulin resistance and hyperglycemia affect the developing brain. Further, our results indicate that earlier detection and pharmacologic treatment of gestational diabetes may attenuate or prevent these changes to neurodevelopment, and that maternal metformin treatment does not influence these aspects of development.

Metformin Use in PCOS Pregnancies Increases the Risk of Offspring Overweight at 4 Years of Age: Follow-Up of Two RCTs

CONTEXT

Metformin is used in pregnancy in women with gestational diabetes mellitus, polycystic ovary syndrome (PCOS), and obesity. Metformin passes the placenta.

OBJECTIVE

To explore the effects of metformin use in PCOS pregnancies on offspring growth to 4 years of age.

DESIGN

Follow-up study of two randomized, double-blind, placebo-controlled trials.

SETTING

Secondary care centers. Eleven public hospitals in Norway.

PARTICIPANTS

One hundred eighty-two children of mothers with PCOS who participated in two randomized controlled trials.

INTERVENTION

Metformin 1700 or 2000 mg/d or placebo from first trimester to delivery in the original studies. No intervention in the current study.

MAIN OUTCOME MEASURES

Height, weight, body mass index (BMI), and overweight/obesity at 4 years of age and head circumference at 1 year of age, converted to z scores.

RESULTS

The difference in height z score means between the groups at 4 years of age was nonsignificant (0.07 [95% confidence interval (CI): -0.22 to 0.36]; P = 0.651). At 4 years of age, the metformin group had higher weight z score than the placebo group [difference in means: 0.38 (0.07 to 0.69); P = 0.017] and higher BMI z score [difference in means: 0.45 (0.11 to 0.78); P = 0.010]. There were more overweight/obese children in the metformin group [26 (32%)] than in the placebo group [14 (18%)] at 4 years of age [odds ratio: 2.17 (1.04 to 4.61); P = 0.038]. The difference in mean head circumference z score at 1 year of age was 0.27 (-0.04 to 0.58; P = 0.093).

CONCLUSION

Metformin-exposed children had higher BMI and increased prevalence of overweight/obesity at 4 years of age.

Outcomes for Women with Gestational Diabetes Treated with Metformin: A Retrospective, Case-Control Study

Metformin is increasingly being used a therapeutic option for the management of gestational diabetes mellitus (GDM). The aim of this study was to compare the maternal characteristics and perinatal outcomes of women with GDM treated with metformin (with or without supplemental insulin) with those receiving other management approaches. A retrospective, case-control study was carried out and 83 women taking metformin were matched 1:1 with women receiving insulin or diet and lifestyle modification alone. Women managed with diet and lifestyle modification had a significantly lower fasting plasma glucose (p < 0.001) and HbA1c (p < 0.01) at diagnosis of GDM. Furthermore, women managed with metformin had a higher early pregnancy body mass index (BMI) compared to those receiving insulin or diet and lifestyle modification (p < 0.001). There was no difference in mode of delivery, birth weight or incidence of large- or small-for-gestational-age neonates between groups. Women receiving glucose lowering therapies had a higher rate of neonatal hypoglycaemia (p < 0.05). The incidence of other adverse perinatal outcomes was similar between groups. Despite their greater BMI, women with metformin-treated GDM did not have an increased risk of adverse perinatal outcomes. Metformin is a useful alternative to insulin in the management of GDM.

The diversity of gestational diabetes: a therapeutic challenge

Metformin as the first drug of choice for glucose lowering in gestational diabetes (GDM) is still controversial, despite recent publications reporting similar outcomes in comparison to insulin, both for offspring and mothers. The use of metformin during pregnancy is increasing and several recent guidelines recommend metformin use in GDM pregnancies. Background, current metformin use and unresolved concerns are discussed in the context of the article from Gante and coworkers.

Therapies for gestational diabetes and their implications for maternal and offspring health: Evidence from human and animal studies

Obesity prior to and during pregnancy is associated with an increased risk of complications during pregnancy. One of the most common complications of pregnancy is gestational diabetes mellitus (GDM), a condition characterized by hyperglycemia and insulin resistance that is diagnosed in the third trimester of pregnancy. GDM predisposes both mothers and their children to increased obesity and cardiometabolic disorders, namely type 2 diabetes and cardiovascular disease. Current treatments include lifestyle changes and insulin injections, but oral anti-diabetic drugs such as metformin and glyburide are increasingly prescribed as they do not require injections. However, the long-term implications of therapies for diabetes during pregnancy on mothers and their offspring are not fully understood. In this review, we describe current treatments for GDM, including the first line lifestyle interventions such as exercise as well as insulin, glyburides and metformin. We also review selected natural health products that are sometimes used by individuals during pregnancy that could also be an effective therapeutic in pregnancies characterized by obesity or GDM. We focus on both the short- and long-term effects of treatments on the health of mothers and their offspring. We review the current literature from clinical research and animal studies.

Metformin in gestational diabetes: the offspring follow-up (MiG TOFU): body composition and metabolic outcomes at 7-9 years of age

OBJECTIVE

To compare body composition and metabolic outcomes at 7-9 years in offspring of women with gestational diabetes (GDM) randomized to metformin (±insulin) or insulin treatment during pregnancy.

RESEARCH DESIGN AND METHODS

Children were assessed at 7 years in Adelaide (n=109/181) and 9 years in Auckland (n=99/396) by anthropometry, bioimpedance analysis (BIA), dual-energy X-ray absorptiometry (DXA), magnetic resonance imaging (MRI) (n=92/99) and fasting bloods (n=82/99).

RESULTS

In the Adelaide subgroup, mothers were similar at enrollment. Women randomized to metformin versus insulin had higher treatment glycemia (p=0.002) and more infants with birth weight >90th percentile (20.7% vs 5.9%; p=0.029). At 7 years, there were no differences in offspring measures. In Auckland, at enrollment, women randomized to metformin had a higher body mass index (BMI) (p=0.08) but gained less weight during treatment (p=0.07). Offspring birth measures were similar. At 9 years, metformin offspring were larger by measures of weight, arm and waist circumferences, waist:height (p<0.05); BMI, triceps skinfold (p=0.05); DXA fat mass and lean mass (p=0.07); MRI abdominal fat volume (p=0.051). Body fat percent was similar between treatment groups by DXA and BIA. Abdominal fat percentages (visceral adipose tissue, subcutaneous adipose tissue and liver) were similar by MRI. Fasting glucose, triglyceride, insulin, insulin resistance, glycosylated hemoglobin (HbA1c), cholesterol, liver transaminases, leptin and adiponectin were similar.

CONCLUSIONS

Metformin or insulin for GDM was associated with similar offspring total and abdominal body fat percent and metabolic measures at 7-9 years. Metformin-exposed children were larger at 9 years. Metformin may interact with fetal environmental factors to influence offspring outcomes.

Insulin for the treatment of women with gestational diabetes

BACKGROUND

Gestational diabetes mellitus (GDM) is associated with short- and long-term complications for the mother and her infant. Women who are unable to maintain their blood glucose concentration within pre-specified treatment targets with diet and lifestyle interventions will require anti-diabetic pharmacological therapies. This review explores the safety and effectiveness of insulin compared with oral anti-diabetic pharmacological therapies, non-pharmacological interventions and insulin regimens.

OBJECTIVES

To evaluate the effects of insulin in treating women with gestational diabetes.

SEARCH METHODS

We searched Pregnancy and Childbirth's Trials Register (1 May 2017), ClinicalTrials.gov, WHO International Clinical Trials Registry Platform (ICTRP) (1 May 2017) and reference lists of retrieved studies.

SELECTION CRITERIA

We included randomised controlled trials (including those published in abstract form) comparing:a) insulin with an oral anti-diabetic pharmacological therapy;b) with a non-pharmacological intervention;c) different insulin analogues;d) different insulin regimens for treating women with diagnosed with GDM.We excluded quasi-randomised and trials including women with pre-existing type 1 or type 2 diabetes. Cross-over trials were not eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study eligibility, risk of bias, and extracted data. Data were checked for accuracy.

MAIN RESULTS

We included 53 relevant studies (103 publications), reporting data for 7381 women. Forty-six of these studies reported data for 6435 infants but our analyses were based on fewer number of studies/participants.Overall, the risk of bias was unclear; 40 of the 53 included trials were not blinded. Overall, the quality of the evidence ranged from moderate to very low quality. The primary reasons for downgrading evidence were imprecision, risk of bias and inconsistency. We report the results for our maternal and infant GRADE outcomes for the main comparison. Insulin versus oral anti-diabetic pharmacological therapyFor the mother, insulin was associated with an increased risk for hypertensive disorders of pregnancy (not defined) compared to oral anti-diabetic pharmacological therapy (risk ratio (RR) 1.89, 95% confidence interval (CI) 1.14 to 3.12; four studies, 1214 women; moderate-quality evidence). There was no clear evidence of a difference between those who had been treated with insulin and those who had been treated with an oral anti-diabetic pharmacological therapy for the risk of pre-eclampsia (RR 1.14, 95% CI 0.86 to 1.52; 10 studies, 2060 women; moderate-quality evidence); the risk of birth by caesarean section (RR 1.03, 95% CI 0.93 to 1.14; 17 studies, 1988 women; moderate-quality evidence); or the risk of developing type 2 diabetes (metformin only) (RR 1.39, 95% CI 0.80 to 2.44; two studies, 754 women; moderate-quality evidence). The risk of undergoing induction of labour for those treated with insulin compared with oral anti-diabetic pharmacological therapy may possibly be increased, although the evidence was not clear (average RR 1.30, 95% CI 0.96 to 1.75; three studies, 348 women; I² = 32%; moderate-quality of evidence). There was no clear evidence of difference in postnatal weight retention between women treated with insulin and those treated with oral anti-diabetic pharmacological therapy (metformin) at six to eight weeks postpartum (MD -1.60 kg, 95% CI -6.34 to 3.14; one study, 167 women; low-quality evidence) or one year postpartum (MD -3.70, 95% CI -8.50 to 1.10; one study, 176 women; low-quality evidence). The outcomes of perineal trauma/tearing or postnatal depression were not reported in the included studies.For the infant, there was no evidence of a clear difference between those whose mothers had been treated with insulin and those treated with oral anti-diabetic pharmacological therapies for the risk of being born large-for-gestational age (average RR 1.01, 95% CI 0.76 to 1.35; 13 studies, 2352 infants; moderate-quality evidence); the risk of perinatal (fetal and neonatal death) mortality (RR 0.85; 95% CI 0.29 to 2.49; 10 studies, 1463 infants; low-quality evidence);, for the risk of death or serious morbidity composite (RR 1.03, 95% CI 0.84 to 1.26; two studies, 760 infants; moderate-quality evidence); the risk of neonatal hypoglycaemia (average RR 1.14, 95% CI 0.85 to 1.52; 24 studies, 3892 infants; low-quality evidence); neonatal adiposity at birth (% fat mass) (mean difference (MD) 1.6%, 95% CI -3.77 to 0.57; one study, 82 infants; moderate-quality evidence); neonatal adiposity at birth (skinfold sum/mm) (MD 0.8 mm, 95% CI -2.33 to 0.73; random-effects; one study, 82 infants; very low-quality evidence); or childhood adiposity (total percentage fat mass) (MD 0.5%; 95% CI -0.49 to 1.49; one study, 318 children; low-quality evidence). Low-quality evidence also found no clear differences between groups for rates of neurosensory disabilities in later childhood: hearing impairment (RR 0.31, 95% CI 0.01 to 7.49; one study, 93 children), visual impairment (RR 0.31, 95% CI 0.03 to 2.90; one study, 93 children), or any mild developmental delay (RR 1.07, 95% CI 0.33 to 3.44; one study, 93 children). Later infant mortality, and childhood diabetes were not reported as outcomes in the included studies.We also looked at comparisons for regular human insulin versus other insulin analogues, insulin versus diet/standard care, insulin versus exercise and comparisons of insulin regimens, however there was insufficient evidence to determine any differences for many of the key health outcomes. Please refer to the main results for more information about these comparisons.

AUTHORS' CONCLUSIONS

The main comparison in this review is insulin versus oral anti-diabetic pharmacological therapies. Insulin and oral anti-diabetic pharmacological therapies have similar effects on key health outcomes. The quality of the evidence ranged from very low to moderate, with downgrading decisions due to imprecision, risk of bias and inconsistency.For the other comparisons of this review (insulin compared with non-pharmacological interventions, different insulin analogies or different insulin regimens), there is insufficient volume of high-quality evidence to determine differences for key health outcomes.Long-term maternal and neonatal outcomes were poorly reported for all comparisons.The evidence suggests that there are minimal harms associated with the effects of treatment with either insulin or oral anti-diabetic pharmacological therapies. The choice to use one or the other may be down to physician or maternal preference, availability or severity of GDM. Further research is needed to explore optimal insulin regimens. Further research could aim to report data for standardised GDM outcomes.

Oral anti-diabetic agents for women with established diabetes/impaired glucose tolerance or previous gestational diabetes planning pregnancy, or pregnant women with pre-existing diabetes

BACKGROUND

While most guidance recommends the use of insulin in women whose pregnancies are affected by pre-existing diabetes, oral anti-diabetic agents may be more acceptable to women. The effects of these oral anti-diabetic agents on maternal and infant health outcomes need to be established in pregnant women with pre-existing diabetes or impaired glucose tolerance, as well as in women with previous gestational diabetes mellitus preconceptionally or during a subsequent pregnancy. This review is an update of a review that was first published in 2010.

OBJECTIVES

To investigate the effects of oral anti-diabetic agents in women with established diabetes, impaired glucose tolerance or previous gestational diabetes who are planning a pregnancy, or pregnant women with pre-existing diabetes, on maternal and infant health. The use of oral anti-diabetic agents for the management of gestational diabetes in a current pregnancy is evaluated in a separate Cochrane Review.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 October 2016) and reference lists of retrieved studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs assessing the effects of oral anti-diabetic agents in women with established diabetes, impaired glucose tolerance or previous gestational diabetes who were planning a pregnancy, or pregnant women with pre-existing diabetes. Cluster-RCTs were eligible for inclusion, but none were identified.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study eligibility, extracted data and assessed the risk of bias of the included RCTs. Review authors checked the data for accuracy, and assessed the quality of the evidence using the GRADE approach.

MAIN RESULTS

We identified six RCTs (707 women), eligible for inclusion in this updated review, however, three RCTs had mixed populations (that is, they included pregnant women with gestational diabetes) and did not report data separately for the relevant subset of women for this review. Therefore we have only included outcome data from three RCTs; data were available for 241 women and their infants. The three RCTs all compared an oral anti-diabetic agent (metformin) with insulin. The women in the RCTs that contributed data had type 2 diabetes diagnosed before or during their pregnancy. Overall, the RCTs were judged to be at varying risk of bias. We assessed the quality of the evidence for selected important outcomes using GRADE; the evidence was low- or very low-quality, due to downgrading because of design limitations (risk of bias) and imprecise effect estimates (for many outcomes only one or two RCTs contributed data).For our primary outcomes there was no clear difference between metformin and insulin groups for pre-eclampsia (risk ratio (RR) 0.63, 95% confidence interval (CI) 0.33 to 1.20; RCTs = 2; participants = 227; very low-quality evidence) although in one RCT women receiving metformin were less likely to have pregnancy-induced hypertension (RR 0.58, 95% CI 0.37 to 0.91; RCTs = 1; participants = 206; low-quality evidence). Women receiving metformin were less likely to have a caesarean section compared with those receiving insulin (RR 0.73, 95% CI 0.61 to 0.88; RCTs = 3; participants = 241; low-quality evidence). In one RCT there was no clear difference between groups for large-for-gestational-age infants (RR 1.12, 95% CI 0.73 to 1.72; RCTs = 1; participants = 206; very low-quality evidence). There were no perinatal deaths in two RCTs (very low-quality evidence). Neonatal mortality or morbidity composite outcome and childhood/adulthood neurosensory disability were not reported.For other secondary outcomes we assessed using GRADE, there were no clear differences between metformin and insulin groups for induction of labour (RR 1.42, 95% CI 0.62 to 3.28; RCTs = 2; participants = 35; very low-quality evidence), though infant hypoglycaemia was reduced in the metformin group (RR 0.34, 95% CI 0.18 to 0.62; RCTs = 3; infants = 241; very low-quality evidence). Perineal trauma, maternal postnatal depression and postnatal weight retention, and childhood/adulthood adiposity and diabetes were not reported.

AUTHORS' CONCLUSIONS

There are insufficient RCT data to evaluate the use of oral anti-diabetic agents in women with established diabetes, impaired glucose tolerance or previous gestational diabetes who are planning a pregnancy, or in pregnant women with pre-existing diabetes. Low to very low-quality evidence suggests possible reductions in pregnancy-induced hypertension, caesarean section birth and neonatal hypoglycaemia with metformin compared with insulin for women with type 2 diabetes diagnosed before or during their pregnancy, and no clear differences in pre-eclampsia, induction of labour and babies that are large-for-gestational age. Further high-quality RCTs that compare any combination of oral anti-diabetic agent, insulin and dietary and lifestyle advice for these women are needed. Future RCTs could be powered to evaluate effects on short- and long-term clinical outcomes; such RCTs could attempt to collect and report on the standard outcomes suggested in this review. We have identified three ongoing studies and four are awaiting classification. We will consider these when this review is updated.

Metformin, the aspirin of the 21st century: its role in gestational diabetes mellitus, prevention of preeclampsia and cancer, and the promotion of longevity

Metformin is everywhere. Originally introduced in clinical practice as an antidiabetic agent, its role as a therapeutic agent is expanding to include treatment of prediabetes mellitus, gestational diabetes mellitus, and polycystic ovarian disease; more recently, experimental studies and observations in randomized clinical trials suggest that metformin could have a place in the treatment or prevention of preeclampsia. This article provides a brief overview of the history of metformin in the treatment of diabetes mellitus and reviews the results of metaanalyses of metformin in gestational diabetes mellitus as well as the treatment of obese, non-diabetic, pregnant women to prevent macrosomia. We highlight the results of a randomized clinical trial in which metformin administration in early pregnancy did not reduce the frequency of large-for-gestational-age infants (the primary endpoint) but did decrease the frequency of preeclampsia (a secondary endpoint). The mechanisms by which metformin may prevent preeclampsia include a reduction in the production of antiangiogenic factors (soluble vascular endothelial growth factor receptor-1 and soluble endoglin) and the improvement of endothelial dysfunction, probably through an effect on the mitochondria. Another potential mechanism whereby metformin may play a role in the prevention of preeclampsia is its ability to modify cellular homeostasis and energy disposition, mediated by rapamycin, a mechanistic target. Metformin has a molecular weight of 129 Daltons and therefore readily crosses the placenta. There is considerable evidence to suggest that this agent is safe during pregnancy. New literature on the role of metformin as a chemotherapeutic adjuvant in the prevention of cancer and in prolonging life and protecting against aging is reviewed briefly. Herein, we discuss the mechanisms of action and potential benefits of metformin.

Metformin use in pregnancy: promises and uncertainties

Metformin has been prescribed in pregnancy for over 40 years; for much of this time, use has been limited both in numbers and geographically, and the evidence base has been confined to observational studies. In early years, perceived safety concerns and lack of availability of the drug in many countries acted as a barrier to use. More recently, RCTs have begun to examine the role of metformin in pregnancy in much-needed detail. However, this evidence base has been interpreted differently in different countries, leading to very wide variation in its current application in pregnancy. In this short review, we will discuss the history of metformin in pregnancy and highlight some of the key clinical trials. We will then consider some of the remaining controversies associated with metformin use in pregnancy, most important of these being the potential for long-term 'programming' effects on the fetus as a result of metformin being able to cross the placenta. We will also consider clinical situations where metformin might be avoided. Finally, we will discuss some future directions for this drug as it reaches its sixtieth anniversary.

Gestational diabetes mellitus-right person, right treatment, right time?

BACKGROUND

Personalised treatment that is uniquely tailored to an individual's phenotype has become a key goal of clinical and pharmaceutical development across many, particularly chronic, diseases. For type 2 diabetes, the importance of the underlying clinical heterogeneity of the condition is emphasised and a range of treatments are now available, with personalised approaches being developed. While a close connection between risk factors for type 2 diabetes and gestational diabetes has long been acknowledged, stratification of screening, treatment and obstetric intervention remains in its infancy.

CONCLUSIONS

Although there have been major advances in our understanding of glucose tolerance in pregnancy and of the benefits of treatment of gestational diabetes, we argue that far more vigorous approaches are needed to enable development of companion diagnostics, and to ensure the efficacious and safe use of novel therapeutic agents and strategies to improve outcomes in this common condition.

The emerging role of metformin in gestational diabetes mellitus

Metformin use during pregnancy is controversial and there is disparity in the acceptance of metformin treatment in women with gestational diabetes mellitus (GDM) in Australia. Despite short term maternal and neonatal safety measures, the placental transfer of metformin during GDM treatment and the absence of long-term safety data in offspring has regulators and prescribers cautious about its use. To determine the current role in GDM management, this literature review describes the physiological changes that occur in GDM and other forms of diabetes in pregnancy (DIP) and international changes in guidelines for GDM diagnosis. Management options are considered, with a focus on the evolving evidence for metformin, its mechanism of action, the maternal, foetal and neonatal outcomes associated with its use and benefit vs risk when compared with the current gold standard, insulin. Investigation reveals a favourable balance of evidence to support the safety and long-term benefits, to mother and child, of using metformin as an alternate to insulin for treatment of GDM. Recent findings of the gastrointestinal-directed action of metformin are at least as important as the hepatic effect and the availability of a novel delayed-release metformin dose form to exploit this new information provides a product and therapeutic strategy ideally suited to the use of metformin in GDM.

Lifestyle interventions for the treatment of women with gestational diabetes

BACKGROUND

Gestational diabetes (GDM) is glucose intolerance, first recognised in pregnancy and usually resolving after birth. GDM is associated with both short- and long-term adverse effects for the mother and her infant. Lifestyle interventions are the primary therapeutic strategy for many women with GDM.

OBJECTIVES

To evaluate the effects of combined lifestyle interventions with or without pharmacotherapy in treating women with gestational diabetes.

SEARCH METHODS

We searched the Pregnancy and Childbirth Group's Trials Register (14 May 2016), ClinicalTrials.gov, WHO International Clinical Trials Registry Platform (ICTRP) (14th May 2016) and reference lists of retrieved studies.

SELECTION CRITERIA

We included only randomised controlled trials comparing a lifestyle intervention with usual care or another intervention for the treatment of pregnant women with GDM. Quasi-randomised trials were excluded. Cross-over trials were not eligible for inclusion. Women with pre-existing type 1 or type 2 diabetes were excluded.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by the Cochrane Collaboration. All selection of studies, data extraction was conducted independently by two review authors.

MAIN RESULTS

Fifteen trials (in 45 reports) are included in this review (4501 women, 3768 infants). None of the trials were funded by a conditional grant from a pharmaceutical company. The lifestyle interventions included a wide variety of components such as education, diet, exercise and self-monitoring of blood glucose. The control group included usual antenatal care or diet alone. Using GRADE methodology, the quality of the evidence ranged from high to very low quality. The main reasons for downgrading evidence were inconsistency and risk of bias. We summarised the following data from the important outcomes of this review. Lifestyle intervention versus control groupFor the mother:There was no clear evidence of a difference between lifestyle intervention and control groups for the risk of hypertensive disorders of pregnancy (pre-eclampsia) (average risk ratio (RR) 0.70; 95% confidence interval (CI) 0.40 to 1.22; four trials, 2796 women; I² = 79%, Tau² = 0.23; low-quality evidence); caesarean section (average RR 0.90; 95% CI 0.78 to 1.05; 10 trials, 3545 women; I² = 48%, Tau² = 0.02; low-quality evidence); development of type 2 diabetes (up to a maximum of 10 years follow-up) (RR 0.98, 95% CI 0.54 to 1.76; two trials, 486 women; I² = 16%; low-quality evidence); perineal trauma/tearing (RR 1.04, 95% CI 0.93 to 1.18; one trial, n = 1000 women; moderate-quality evidence) or induction of labour (average RR 1.20, 95% CI 0.99 to 1.46; four trials, n = 2699 women; I² = 37%; high-quality evidence).More women in the lifestyle intervention group had met postpartum weight goals one year after birth than in the control group (RR 1.75, 95% CI 1.05 to 2.90; 156 women; one trial, low-quality evidence). Lifestyle interventions were associated with a decrease in the risk of postnatal depression compared with the control group (RR 0.49, 95% CI 0.31 to 0.78; one trial, n = 573 women; low-quality evidence).For the infant/child/adult:Lifestyle interventions were associated with a reduction in the risk of being born large-for-gestational age (LGA) (RR 0.60, 95% CI 0.50 to 0.71; six trials, 2994 infants; I² = 4%; moderate-quality evidence). Birthweight and the incidence of macrosomia were lower in the lifestyle intervention group.Exposure to the lifestyle intervention was associated with decreased neonatal fat mass compared with the control group (mean difference (MD) -37.30 g, 95% CI -63.97 to -10.63; one trial, 958 infants; low-quality evidence). In childhood, there was no clear evidence of a difference between groups for body mass index (BMI) ≥ 85th percentile (RR 0.91, 95% CI 0.75 to 1.11; three trials, 767 children; I² = 4%; moderate-quality evidence).There was no clear evidence of a difference between lifestyle intervention and control groups for the risk of perinatal death (RR 0.09, 95% CI 0.01 to 1.70; two trials, 1988 infants; low-quality evidence). Of 1988 infants, only five events were reported in total in the control group and there were no events in the lifestyle group. There was no clear evidence of a difference between lifestyle intervention and control groups for a composite of serious infant outcome/s (average RR 0.57, 95% CI 0.21 to 1.55; two trials, 1930 infants; I² = 82%, Tau² = 0.44; very low-quality evidence) or neonatal hypoglycaemia (average RR 0.99, 95% CI 0.65 to 1.52; six trials, 3000 infants; I² = 48%, Tau² = 0.12; moderate-quality evidence). Diabetes and adiposity in adulthood and neurosensory disability in later childhoodwere not prespecified or reported as outcomes for any of the trials included in this review.

AUTHORS' CONCLUSIONS

Lifestyle interventions are the primary therapeutic strategy for women with GDM. Women receiving lifestyle interventions were less likely to have postnatal depression and were more likely to achieve postpartum weight goals. Exposure to lifestyle interventions was associated with a decreased risk of the baby being born LGA and decreased neonatal adiposity. Long-term maternal and childhood/adulthood outcomes were poorly reported.The value of lifestyle interventions in low-and middle-income countries or for different ethnicities remains unclear. The longer-term benefits or harms of lifestyle interventions remains unclear due to limited reporting.The contribution of individual components of lifestyle interventions could not be assessed. Ten per cent of participants also received some form of pharmacological therapy. Lifestyle interventions are useful as the primary therapeutic strategy and most commonly include healthy eating, physical activity and self-monitoring of blood glucose concentrations.Future research could focus on which specific interventions are most useful (as the sole intervention without pharmacological treatment), which health professionals should give them and the optimal format for providing the information. Evaluation of long-term outcomes for the mother and her child should be a priority when planning future trials. There has been no in-depth exploration of the costs 'saved' from reduction in risk of LGA/macrosomia and potential longer-term risks for the infants.

Efficacy of metformin in improving glycaemic control & perinatal outcome in gestational diabetes mellitus: A non-randomized study

BACKGROUND & OBJECTIVES

Gestational diabetes mellitus (GDM) can cause adverse perinatal outcome if not treated. Although insulin therapy has been the main treatment modality over decades but considering its cost and parenteral mode of administration, it does not seem to be appropriate, especially in low-resource settings. The objective of this study was to evaluate the role of metformin in GDM and know its efficacy as well as adverse effect on foetus and mother.

METHODS

All pregnant women with GDM who were not controlled on medical nutrition therapy and required metformin therapy were included in the study. Careful monitoring of blood sugar was done. Development of any maternal or foetal complications and adverse effect were recorded.

RESULTS

A total of 2797 pregnant women were screened, of whom 233 (8.3%) were found to have GDM. Of the 64 women with GDM (28.7%) who required metformin therapy, majority (93.8%) achieved blood sugar control, whereas three (4.7%) women failed. Caesarean section rate was 54 per cent, and 15.6 per cent neonates were large for gestational age. Only two (3.1%) women had gastrointestinal side effects which were minor and got resolved with time. No case of hypoglycaemia or perinatal mortality was reported.

INTERPRETATION & CONCLUSIONS

Our findings indicate that metformin may be used as a safe and effective oral hypoglycaemic agent in GDM, especially in low-resource settings where cost, storage and compliance are logistic issues. However, long-term follow up studies are needed to solve issues related to its safety in pregnancy.

Metformin; a review of its history and future: from lilac to longevity

Metformin is a widely prescribed medication that has been used to treat children with type 2 diabetes in the United States for the past 15 years. Metformin now has a variety of clinical applications in pediatrics, and its potential clinical uses continue to expand. In addition to reviewing the current understanding of its mechanisms of action including the newly discovered effects on the gastrointestinal tract, we will also discuss current clinical uses in pediatrics, including in type 1 diabetes. Finally, we examine the existing state of monitoring for metformin efficacy and side effects and discuss prospective future clinical uses.

Developmental origins of NAFLD: a womb with a clue

Changes in the maternal environment leading to an altered intrauterine milieu can result in subtle insults to the fetus, promoting increased lifetime disease risk and/or disease acceleration in childhood and later in life. Particularly worrisome is that the prevalence of NAFLD is rapidly increasing among children and adults, and is being diagnosed at increasingly younger ages, pointing towards an early-life origin. A wealth of evidence, in humans and non-human primates, suggests that maternal nutrition affects the placenta and fetal tissues, leading to persistent changes in hepatic metabolism, mitochondrial function, the intestinal microbiota, liver macrophage activation and susceptibility to NASH postnatally. Deleterious exposures in utero include fetal hypoxia, increased nutrient supply, inflammation and altered gut microbiota that might produce metabolic clues, including fatty acids, metabolites, endotoxins, bile acids and cytokines, which prime the infant liver for NAFLD in a persistent manner and increase susceptibility to NASH. Mechanistic links to early disease pathways might involve shifts in lipid metabolism, mitochondrial dysfunction, pioneering gut microorganisms, macrophage programming and epigenetic changes that alter the liver microenvironment, favouring liver injury. In this Review, we discuss how maternal, fetal, neonatal and infant exposures provide developmental clues and mechanisms to help explain NAFLD acceleration and increased disease prevalence. Mechanisms identified in clinical and preclinical models suggest important opportunities for prevention and intervention that could slow down the growing epidemic of NAFLD in the next generation.

Perceptions and Concerns Regarding Diabetes Mellitus During Pregnancy Among American Indian Women

Diabetes among American Indian (AI) people is a. condition that creates excessive morbidity and mortality and is a significant health disparity. This research delineated culturally constructed models of diabetes mellitus (DM) among 97 pregnant women in 2 large AI Nations to Oklahoma. Analysis of data revealed intense anxiety, fear, and dread related to DM during pregnancy. The sample was stratified by DM status: (a) absence of DM (n = 66), (b) DM prior to pregnancy (n = 4), and (c) gestational (n = 27). Structured and semistructured interviews elicited patient culturally based explanatory models (EMs) of etiology, course, and treatment. The research incorporated an integrated phenomenologic and ethnographic approach and yielded both quantitative and qualitative data. General findings comprised the following main categories of patients' concerns regarding DM as an illness: (a) care-seeking behaviors, (b) medical management, (c) adherence and self-management, (d) complications, and (e) the conceptual sense of DM as a "severe" and feared condition. Many findings varied according to acculturation status, but all included significant fear and anxiety surrounding (a) the health and well-being of the unborn child, (b) the use of insulin injections, (c) blindness, (d) amputation, and (e) death, but with (f) a paradoxically lowered anxiety level about diabetes severity overall, while at the same time expressing extreme dread of specific outcomes. The latter finding is considered consistent with the presence of chronic conditions that can usually be managed, yet still having risk if severe.

[Gestational diabetes mellitus]

Gestational diabetes (GDM) is defined as any degree of glucose intolerance with onset during pregnancy and is associated with increased feto-maternal morbidity as well as long-term complications in mothers and offspring. Women detected to have diabetes early in pregnancy receive the diagnosis of overt, non-gestational, diabetes (glucose: fasting > 126 mg/dl, spontaneous > 200 mg/dl or HbA1c > 6.5 % before 20 weeks of gestation). GDM is diagnosed by an oral glucose tolerance test (OGTT) or fasting glucose concentrations (> 92 mg/dl). Screening for undiagnosed type 2 diabetes at the first prenatal visit (Evidence level B) is recommended in women at increased risk using standard diagnostic criteria (high risk: history of GDM or pre-diabetes (impaired fasting glucose or impaired glucose tolerance); malformation, stillbirth, successive abortions or birth weight > 4,500 g in previous pregnancies; obesity, metabolic syndrome, age > 45 years, vascular disease; clinical symptoms of diabetes (e. g. glucosuria)). Performance of the OGTT (120 min; 75 g glucose) may already be indicated in the first trimester in some women but is mandatory between 24 and 28 gestational weeks in all pregnant women with previous non-pathological glucose metabolism (Evidence level B). Based on the results of the Hyperglycemia and Adverse Pregnancy Outcome (HAPO) study GDM is defined, if fasting venous plasma glucose exceeds 92 mg/dl or 1 h 180 mg/dl or 2 h 153 mg/dl after glucose loading (OGTT; international consensus criteria). In case of one pathological value a strict metabolic control is mandatory. This diagnostic approach was recently also recommended by the WHO. All women should receive nutritional counseling and be instructed in blood glucose self-monitoring and to increase physical activity to moderate intensity levels- if not contraindicated. If blood glucose levels cannot be maintained in the normal range (fasting < 95 mg/dl and 1 h after meals < 140 mg/dl) insulin therapy should be initiated as first choice. Maternal and fetal monitoring is required in order to minimize maternal and fetal/neonatal morbidity and perinatal mortality. After delivery all women with GDM have to be reevaluated as to their glucose tolerance by a 75 g OGTT (WHO criteria) 6-12 weeks postpartum and every 2 years in case of normal glucose tolerance (Evidence level B). All women have to be instructed about their (sevenfold increased relative) risk of type 2 diabetes at follow-up and possibilities for diabetes prevention, in particular weight management and maintenance/increase of physical activity. Monitoring of the development of the offspring and recommendation of healthy lifestyle of the children and family is recommended.

Implications of maternal obesity on fetal growth and the role of ultrasound

Over fifty percent of women entering pregnancy are overweight or obese. This has a significant impact on short and long term maternal and infant health outcomes, and the intergenerational effects of obesity are now a major public health problem globally. Areas covered: There are two major pathways contributing to fetal growth. Glucose and insulin directly affect growth, while other substrates such as leptin, adiponectin and insulin-like growth factors indirectly influence growth through structural and morphological effects on the placenta, uteroplacental blood flow, and regulation of placental transporters. Advances in ultrasonography over the past decade have led to interest in the prediction of the fetus at risk of overgrowth and adiposity utilizing both standard ultrasound biometry and fetal body composition measurements. However, to date there is no consensus regarding the definition of fetal overgrowth, its reporting, and clinical management. Expert commentary: Maternal dietary intervention targeting the antenatal period appear to be too late to sufficiently affect fetal growth. The peri-conceptual period and early pregnancy are being evaluated to determine if the intergenerational effects of maternal obesity can be altered to improve newborn, infant and child health.

Short- and long-term outcomes of metformin compared with insulin alone in pregnancy: a systematic review and meta-analysis

AIM

To assess the short- and long-term maternal and fetal impact of metformin in pregnancy compared with insulin.

METHODS

We performed a comprehensive literature search of MEDLINE, EMBASE, BIOSIS, Cochrane Database of Systematic Reviews and ClinicalTrials.gov. Eligible studies were randomized control trials (RCTs) or follow-up of an RCT that: (1) compared metformin with insulin in pregnancy in women with gestational diabetes mellitus or Type 2 diabetes; and (2) reported maternal or fetal outcomes of interest. Two reviewers extracted the data, evaluated study quality and calculated pooled estimates.

RESULTS

Sixteen studies (n = 2165 in quantitative analysis) were included. Metformin lowered the risk of neonatal hypoglycaemia [risk ratio (RR) = 0.63; 95% confidence interval (95% CI), 0.45 to 0.87], large for gestational age babies (RR = 0.80; 95% CI, 0.64 to 0.99), pregnancy-induced hypertension (RR = 0.56; 95% CI, 0.37 to 0.85) and total maternal pregnancy weight gain [mean difference (MD) -2.07; 95% CI -2.88 to -1.27]. Metformin did not increase preterm delivery (RR = 1.18; 95% CI 0.67 to 2.07), small for gestational age babies (RR = 1.20; 95% CI, 0.67 to 2.14), perinatal mortality (RR = 0.82; 95% CI, 0.17 to 3.92) or Caesarean section (RR = 0.97; 95% CI, 0.80 to 1.19). Long-term outcome information is limited.

CONCLUSIONS

Our review found that metformin had no short-term adverse effects on pregnancy, potential benefits in the neonatal period, but limited long-term follow-up information. Prior to routine use, we recommend further follow-up studies of offspring exposed to metformin in utero.

A story of metformin-butyrate synergism to control various pathological conditions as a consequence of gut microbiome modification: Genesis of a wonder drug?

The most widely prescribed oral anti-diabetic agent today in the world today is a member of the biguanide class of drugs called metformin. Apart from its use in diabetes, it is currently being investigated for its potential use in many diseases such as cancer, cardiovascular diseases, Alzheimer's disease, obesity, comorbidities of diabetes such as retinopathy, nephropathy to name a few. Numerous in-vitro and in-vivo studies as well as clinical trials have been and are being conducted with a vast amount of literature being published every day. Numerous mechanisms for this drug have been proposed, but they have been unable to explain all the actions observed clinically. It is of interest that insulin has a stimulatory effect on cellular growth. Metformin sensitizes the insulin action but believed to be beneficial in cancer. Like -wise metformin is shown to have beneficial effects in opposite sets of pathological scenario looking from insulin sensitization point of view. This requires a comprehensive review of the disease conditions which are claimed to be affected by metformin therapy. Such a comprehensive review is presently lacking. In this review, we begin by examining the history of metformin before it became the most popular anti-diabetic medication today followed by a review of its relevant molecular mechanisms and important clinical trials in all areas where metformin has been studied and investigated till today. We also review novel mechanistic insight in metformin action in relation to microbiome and elaborate implications of such aspect in various disease states. Finally, we highlight the quandaries and suggest potential solutions which will help the researchers and physicians to channel their research and put this drug to better use.

Telemedicine Technologies for Diabetes in Pregnancy: A Systematic Review and Meta-Analysis

Background

Diabetes in pregnancy is a global problem. Technological innovations present exciting opportunities for novel approaches to improve clinical care delivery for gestational and other forms of diabetes in pregnancy.

Objective

To perform an updated and comprehensive systematic review and meta-analysis of the literature to determine whether telemedicine solutions offer any advantages compared with the standard care for women with diabetes in pregnancy.

Methods

The review was developed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) framework. Randomized controlled trials (RCT) in women with diabetes in pregnancy that compared telemedicine blood glucose monitoring with the standard care were identified. Searches were performed in SCOPUS and PubMed, limited to English language publications between January 2000 and January 2016. Trials that met the eligibility criteria were scored for risk of bias using the Cochrane Collaborations Risk of Bias Tool. A meta-analysis was performed using Review Manager software version 5.3 (Nordic Cochrane Centre, Cochrane Collaboration).

Results

A total of 7 trials were identified. Meta-analysis demonstrated a modest but statistically significant improvement in HbA1c associated with the use of a telemedicine technology. The mean HbA1c of women using telemedicine was 5.33% (SD 0.70) compared with 5.45% (SD 0.58) in the standard care group, representing a mean difference of −0.12% (95% CI −0.23% to −0.02%). When this comparison was limited to women with gestational diabetes mellitus (GDM) only, the mean HbA1c of women using telemedicine was 5.22% (SD 0.70) compared with 5.37% (SD 0.61) in the standard care group, mean difference −0.14% (95% CI −0.25% to −0.04%). There were no differences in other maternal and neonatal outcomes reported.

Conclusions

There is currently insufficient evidence that telemedicine technology is superior to standard care for women with diabetes in pregnancy; however, there was no evidence of harm. No trials were identified that assessed patient satisfaction or cost of care delivery, and it may be in these areas where these technologies may be found most valuable.

Gestational Diabetes Mellitus:current knowledge and unmet needs

Gestational diabetes mellitus (GDM) is a global health concern, not only because its prevalence is high and on the increase, but also because of the potential implications for the health of mothers and their offspring. Unfortunately, there is considerable controversy in the literature surrounding the diagnosis and treatment of GDM, as well as the possible long-term consequences for the offspring. As a result, worldwide there is a lack of uniformly accepted diagnostic criteria and the advice regarding the treatment of GDM, including diet, insulin therapy, and the use of oral blood glucose-lowering agents, is highly variable. In this review we provide an overview of the important issues in the field of GDM, including diagnostic criteria, different treatment regimens available, and the long-term consequences of GDM in the offspring.