Oral Agents for the Treatment of Gestational Diabetes

Prevalence and treatment of gestational diabetes in Norway 2010-2020

AIMS

Estimate prevalence of gestational diabetes mellitus (GDM) and its treatment in Norway 2010-2020 and explore impact of new national GDM guidelines in 2017.

METHODS

We identified women giving birth in a nationwide cohort study using registers on births, prescriptions, education, primary and specialist care. For each year, we estimated prevalence of GDM overall, by BMI, age, education, and mother's birthplace; proportions of GDM pregnancies receiving pharmacological treatment; and distribution of the gestational week when GDM was diagnosed.

RESULTS

In 633,169 pregnancies, prevalence of GDM increased from 2.6 % in 2010 to 6.0 % in 2016, then stabilized. Similar patterns were seen across strata of BMI, age, education, and maternal birthplace, although prevalence was higher with higher BMI, higher age, lower education, and mothers born in Asia, Africa, or Middle East. The proportion of the GDM population pharmacologically treated increased from 11.6 % in 2010 to 13.6 % in 2016 and 31.6 % in 2020. GDM was diagnosed in recommended gestational week 24-28 in 19 % versus 45 % of GDM pregnancies in 2010 and 2020, respectively.

CONCLUSIONS

Both the proportion diagnosed with GDM within recommended time of screening, and who received pharmacological treatment, increased substantially following new guidelines in 2017. Prevalence of GDM increased from 2010 to 2016, then plateaued.

Box Behnken optimization of cubosomes for enhancing the anticancer activity of metformin: Design, characterization, and in-vitro cell proliferation assay on MDA-MB-231 breast and LOVO colon cancer cell lines

This study aimed to formulate and statistically optimize cubosomal formulations of metformin (MTF) to enhance its breast anticancer activity. A Box Behnken design was employed using Design-Expert® software. The formulation variables were glyceryl monooleate concentration (GMO) w/w%, Pluronic F-127 concentration (PF127) w/w% and Tween 80 concentration w/w% whereas Entrapment efficiency (EE%), Vesicles' size (VS) and Zeta potential (ZP) were set as the dependent responses. The design expert software was used to perform the process of optimization numerically. X ray diffraction (XRD), Transmission electron microscope (TEM), in-vitro release study, short-term stability study, and in in-vitro cell proliferation assay on the MDA-MB-231 breast cancer and LOVO cancer cell lines were used to validate the optimized cubosomal formulation. The optimized formulation had a composition of 4.35616 (w/w%) GMO, 5 (w/w%) PF127 and 7.444E-6 (w/w%) Tween 80 with a desirability of 0.733. The predicted values for EE%, VS and ZP were 78.0592%, 307.273 nm and - 26.8275 mV, respectively. The validation process carried out on the optimized formula revealed that there were less than a 5% variance from the predicted responses. The XRD thermograms showed that MTF was encapsulated inside the cubosomal vesicles. TEM images of the optimized MTF cubosomal formulation showed spherical non-aggregated nanovesicles. Moreover, it revealed a sustained release profile of MTF in comparison to the MTF solution. Stability studies indicated that optimum cubosomal formulation was stable for thirty days. Cytotoxicity of the optimized cubosomal formulation was enhanced on the MDA-MB-231 breast and LOVO cancer cell lines compared to MTF solution even at lower concentrations. However, it showed superior cytotoxic effect on breast cancer cell line. So, cubosomes could be considered a promising carrier of MTF to treat breast and colon cancers.

Case Report: Abruptio placentae and epileptic seizure after occurrence of perinatal hyperglycaemia in woman with gestational diabetes mellitus and hypertriglyceridemia-induced acute pancreatitis

Hypertriglyceridemia-induced acute pancreatitis seldom occurs in the second trimester of pregnancy with gestational diabetes mellitus. For these patients, the existing knowledge on concomitant hyperglycemia is not sufficient. We report a case of abruptio placentae and epileptic seizure following perinatal hyperglycaemia in woman with gestational diabetes mellitus and hypertriglyceridemia-induced acute pancreatitis. The occurrence of abruptio placentae and epileptic seizure may be associated with concomitant hyperglycemia, and the epileptic seizure was terminated after she underwent treatment with insulin. We should pay more attention to the adverse effects of perinatal hyperglycemia and continue to give appropriate insulin treatment even if patients have passed the acute phase of hypertriglyceridemia-induced acute pancreatitis.

Efficacy and safety of metformin compared to insulin in gestational diabetes: a systemic review and meta-analysis of Chinese randomized controlled trials

BACKGROUND

Metformin is widely used for the treatment of gestational diabetes. Although some meta-analyses are conducted on the efficacy and safety of metformin, none of them are focused on the Chinese population. The efficacy and safety of metformin in the Chinese GDM population are unknown.

AIM

The study aimed to compare metformin to insulin regarding the safety and efficacy in Chinese GDM patients using randomized controlled trials (RCTs) conducted in China.

METHOD

Chinese databases (Wanfang, CNKI, VIP, and CBM), PubMed, Embase, Cochrane library, and Scopus were searched for RCTs. The last search date was October 18, 2021.

RESULTS

Fifty RCTs (4663 patients) were included in this study after screening. Six outcomes were analyzed. In the main analysis, metformin had lower risk of respiratory distress syndrome (RDS, OR, 0.28; 95% CI 0.16-0.51; P < 0.0001), premature birth (OR, 0.42; 95% CI 0.21-0.85, P = 0.02), and neonatal hypoglycemia (OR, 0.34; 95% CI 0.24-0.48; P < 0.00001) compared to insulin. Moreover, the metformin group is better than the insulin group concerning all other outcomes such as maternal glycemic control and glycated hemoglobin. Subgroup analysis confirmed that metformin has better outcomes than all types of insulin except for RDS, premature birth, 2 h postprandial blood glucose, and glycated hemoglobin.

CONCLUSION

Metformin is considered to be a safe and effective alternative to insulin for the management of GDM if patients refuse insulin due to any reasons in China.

Machine Learning-Based Risk Stratification for Gestational Diabetes Management

Gestational diabetes mellitus (GDM) is often diagnosed during the last trimester of pregnancy, leaving only a short timeframe for intervention. However, appropriate assessment, management, and treatment have been shown to reduce the complications of GDM. This study introduces a machine learning-based stratification system for identifying patients at risk of exhibiting high blood glucose levels, based on daily blood glucose measurements and electronic health record (EHR) data from GDM patients. We internally trained and validated our model on a cohort of 1148 pregnancies at Oxford University Hospitals NHS Foundation Trust (OUH), and performed external validation on 709 patients from Royal Berkshire Hospital NHS Foundation Trust (RBH). We trained linear and non-linear tree-based regression models to predict the proportion of high-readings (readings above the UK's National Institute for Health and Care Excellence [NICE] guideline) a patient may exhibit in upcoming days, and found that XGBoost achieved the highest performance during internal validation (0.021 [CI 0.019-0.023], 0.482 [0.442-0.516], and 0.112 [0.109-0.116], for MSE, R2, MAE, respectively). The model also performed similarly during external validation, suggesting that our method is generalizable across different cohorts of GDM patients.

Metformin versus insulin therapy for gestational diabetes: Effects on offspring anthropometrics and metabolism at the age of 9 years: A follow-up study of two open-label, randomized controlled trials

AIMS

To compare anthropometrics, and lipid and glucose metabolism in the 9-year-old offspring of mothers treated with metformin or insulin for gestational diabetes mellitus (GDM).

MATERIALS AND METHODS

This was a Finnish two-centre, 9-year follow-up study of two open-label, randomized controlled trials comparing the effects observed in the offspring of mothers who received metformin and insulin treatment for GDM. Measurements included anthropometrics, blood pressure, lipoproteins, and oral glucose tolerance tests. This study was registered with ClinicalTrials.gov, number NCT02417090.

RESULTS

At the age of 9 years 172 children (55% of the original study cohort, 82 from the metformin and 90 from the insulin group) participated in the study. No differences were found between the 9-year-old offspring groups in anthropometric variables, including body mass index and waist-to-height ratio. The offspring in the metformin group had higher high-density lipoprotein (HDL) cholesterol concentrations (1.72 vs. 1.54 mmol/L; P = 0.039) but lower low-density lipoprotein cholesterol (2.39 vs. 2.58 mmol/L; P = 0.046) and apolipoprotein B concentrations (0.63 vs. 0.67 g/L; P = 0.043) than the offspring in the insulin group. The difference in HDL cholesterol concentration was found to be significant only in boys (P = 0.003). The 2-hour glucose value in the oral glucose tolerance test was 0.6-mmol/L lower in boys from the metformin group than in those from the insulin group (P = 0.015).

CONCLUSIONS

Metformin treatment for GDM is associated with similar offspring growth and glucose metabolism but a more favourable lipid profile at the age of 9 years as compared to insulin treatment.

Changing patterns in medication prescription for gestational diabetes during a time of guideline change in the USA: a cross-sectional study

OBJECTIVE

To define patterns of prescription and factors associated with choice of pharmacotherapy for gestational diabetes mellitus (GDM), namely metformin, glyburide and insulin, during a period of evolving professional guidelines.

DESING

Cross-sectional study.

SETTING

US commercial insurance beneficiaries from Market-Scan (late 2015 to 2018).

STUDY DESIGN

We included women with GDM, singleton gestations, 15-51 years of age on pharmacotherapy. The exposure was pharmacy claims for metformin, glyburide and insulin.

MAIN OUTCOMES

Pharmacotherapy for GDM with either oral agent, metformin or glyburide, compared with insulin as the reference, and secondarily, consequent treatment modification (addition and/or change) to metformin, glyburide or insulin.

RESULTS

Among 37 762 women with GDM, we analysed data from 10 407 (28%) with pharmacotherapy, 21% with metformin (n = 2147), 48% with glyburide (n = 4984) and 31% with insulin (n = 3276). From late 2015 to 2018, metformin use increased from 17 to 29%, as did insulin use from 26 to 44%, whereas glyburide use decreased from 58 to 27%. By 2018, insulin was the most common pharmacotherapy for GDM; metformin was more likely to be prescribed by 9% compared with late 2015/16, but glyburide was less likely by 45%. Treatment modification occurred in 20% of women prescribed metformin compared with 2% with insulin and 8% with glyburide.

CONCLUSIONS

Insulin followed by metformin has replaced glyburide as the most common pharmacotherapy for GDM among a privately insured US population during a time of evolving professional guidelines. Further evaluation of the relative effectiveness and safety of metformin compared with insulin is needed.

TWEETABLE ABSTRACT

Insulin followed by metformin has replaced glyburide as the most common pharmacotherapy for gestational diabetes mellitus in the USA.

Pregnancy in Women With Monogenic Diabetes due to Pathogenic Variants of the Glucokinase Gene: Lessons and Challenges

Heterozygous loss-of-function variants of the glucokinase (GCK) gene are responsible for a subtype of maturity-onset diabetes of the young (MODY). GCK-MODY is characterized by a mild hyperglycemia, mainly due to a higher blood glucose threshold for insulin secretion, and an up-regulated glucose counterregulation. GCK-MODY patients are asymptomatic, are not exposed to diabetes long-term complications, and do not require treatment. The diagnosis of GCK-MODY is made on the discovery of hyperglycemia by systematic screening, or by family screening. The situation is peculiar in GCK-MODY women during pregnancy for three reasons: 1. the degree of maternal hyperglycemia is sufficient to induce pregnancy adverse outcomes, as in pregestational or gestational diabetes; 2. the probability that a fetus inherits the maternal mutation is 50% and; 3. fetal insulin secretion is a major stimulus of fetal growth. Consequently, when the fetus has not inherited the maternal mutation, maternal hyperglycemia will trigger increased fetal insulin secretion and growth, with a high risk of macrosomia. By contrast, when the fetus has inherited the maternal mutation, its insulin secretion is set at the same threshold as the mother's, and no fetal growth excess will occur. Thus, treatment of maternal hyperglycemia is necessary only in the former situation, and will lead to a risk of fetal growth restriction in the latter. It has been recommended that the management of diabetes in GCK-MODY pregnant women should be guided by assessment of fetal growth by serial ultrasounds, and institution of insulin therapy when the abdominal circumference is ≥ 75th percentile, considered as a surrogate for the fetal genotype. This strategy has not been validated in women with in GCK-MODY. Recently, the feasibility of non-invasive fetal genotyping has been demonstrated, that will improve the care of these women. Several challenges persist, including the identification of women with GCK-MODY before or early in pregnancy, and the modalities of insulin therapy. Yet, retrospective observational studies have shown that fetal genotype, not maternal treatment with insulin, is the main determinant of fetal growth and of the risk of macrosomia. Thus, further studies are needed to specify the management of GCK-MODY pregnant women during pregnancy.

Non-coding RNAs in diabetes mellitus and diabetic cardiovascular disease

More than 10% of the world's population already suffers from varying degrees of diabetes mellitus (DM), but there is still no cure for the disease. Cardiovascular disease (CVD) is one of the most common and dangerous of the many health complications that can be brought on by DM, and has become the leading cause of death in people with diabetes. While research on DM and associated CVD is advancing, the specific mechanisms of their development are still unclear. Given the threat of DM and CVD to humans, the search for new predictive markers and therapeutic ideas is imminent. Non-coding RNAs (ncRNAs) have been a popular subject of research in recent years. Although they do not encode proteins, they play an important role in living organisms, and they can cause disease when their expression is abnormal. Numerous studies have observed aberrant ncRNAs in patients with DM complications, suggesting that they may play an important role in the development of DM and CVD and could potentially act as biomarkers for diagnosis. There is additional evidence that treatment with existing drugs for DM, such as metformin, alters ncRNA expression levels, suggesting that regulation of ncRNA expression may be a key mechanism in future DM treatment. In this review, we assess the role of ncRNAs in the development of DM and CVD, as well as the evidence for ncRNAs as potential therapeutic targets, and make use of bioinformatics to analyze differential ncRNAs with potential functions in DM.

The Use of Oral Hypoglycemic Agents during Pregnancy: An Alternative to Insulin?

OBJECTIVE

Gestational Diabetes Mellitus (GDM) and Type 2 Diabetes Mellitus (DM2) are metabolic disorders characterized by increased insulin resistance. Although insulin is the treatment of choice in pregnant patients with DM, the prescription of oral hypoglycemic agents (OHA) has been increasing among practitioners. This study aimed to evaluate the maternal and neonatal outcomes when oral hypoglycemic agents were used in diabetic pregnant women.

METHODS

Medical records from the Maternal-Infant Care Unit Clinics SoM-UPR (n=149) were reviewed. Patients that were treated with metformin, sulfonylurea or insulin were included. Maternal and neonatal outcomes were compared between groups.

RESULTS

Patient's mean age was 28 ± 6 years. The majority had GDM (91%). The most common comorbidity was hypertension (9.9%). Lifestyle modification was used as treatment in 77% of patients during the second trimester, but its use decreased to 33% during the third trimester. Insulin was the treatment of choice. Among the OHA, sulfonylurea was preferred. Postprandial glucose levels were lower in patients who used insulin as compared to those without medications.

CONCLUSION

No significant differences were found in maternal outcomes such as C-section, induction of labor, episiotomy or preterm labor, or neonatal outcomes such as macrosomia, neonatal hypoglycemia or congenital abnormalities among treatment groups. OHA can be considered as an alternative to insulin for the treatment of DM during pregnancy in selected cases.

Nuciferine administration in C57BL/6J mice with gestational diabetes mellitus induced by a high-fat diet: the improvement of glycolipid disorders and intestinal dysbacteriosis

Gestational diabetes mellitus (GDM) has become a global health concern as the main result of its contribution to the high risk of adverse pregnancy outcomes for both the mother and fetus. However, there is absence of an ideal and widely acceptable therapy. Nuciferine has previously been shown to exert beneficial effects in various metabolic diseases. This study aimed to investigate the potential therapeutic efficacy of nuciferine on GDM in C57BL/6J mice induced by a high-fat diet (HFD), which has not been reported before. The results showed that nuciferine improved glucose intolerance, reduced lipid accumulation and increased the glycogen content within hepatocytes, and decreased placental lipid and glycogen deposition, thus ameliorating glycolipid disorders in GDM mice. Additionally, nuciferine protected against histological degeneration of metabolism-associated critical organs including the liver, pancreas, and abdominal adipose tissue. Most interestingly, nuciferine could correct intestinal dysbacteriosis in GDM mice, as evidenced by the elevation of probiotic abundances consisting of Akkermansia, Lactobacillus, and Bifidobacterium, which were all negatively correlated with serum and liver triglyceride (TG) and positively associated with hepatic glycogen, and the reduction of conditional pathogen abundances including Escherichia-Shigella and Staphylococcus, and the latter was positively related to serum and liver TG and negatively linked with liver glycogen. Collectively, these findings suggest that nuciferine as a food-borne strategy played important roles in the management of GDM.

Gestational diabetes mellitus - A metabolic and reproductive disorder

Maternal health associated with Gestational Diabetes Mellitus (GDM) has been gaining significant research attention due to its severe risk and adverse health effects. GDM is the leading health disease in pregnant women. It is the most common metabolic disease and it can affect up to 25% of women during pregnancy. Pregnancy is a sensitive period that impacts both pregnant women and their unborn children's long-term health. It is a well-known fact that the leading causes of disease and mortality worldwide are diabetes mellitus and cancer, and specifically, women with diabetes mellitus are at a higher risk of developing breast cancer (BC). Women who have diabetes are equally vulnerable to reproductive diseases. Reproductive dysfunctions with diabetes are mainly attributed to coexisting polycystic ovarian syndrome (PCOS), obesity, and hyperinsulinemia, etc. Moreover, India has long been recognized as the world's diabetic capital, and it is widely acknowledged that particularly pregnant and lactating women are among the most affected by diabetes. In India, one-third (33%) of women with GDM had a history of maternal diabetes. Nevertheless, the latest research suggests that gestational diabetes is also a risk factor for cardiometabolic diseases of the mother and offspring. Therefore, in the 21st century, GDM imposes a major challenge for healthcare professionals. We intend to explore the role of diabetes on female reproductive function throughout various stages of life in the perspective of the changing prognosis, prevalence, and prevention of GDM.

Characterization of women with gestational diabetes who failed to achieve glycemic control by lifestyle modifications

PURPOSE

To identify specific characteristics of women diagnosed with gestational diabetes who failed to achieve good glycemic control by lifestyle modifications only.

METHODS

Retrospective analysis of women carrying a singleton pregnancy diagnosed with gestational diabetes. The cohort included 314 women who achieved good glycemic control by lifestyle modifications and 328 women who required anti-diabetic medications. Lifestyle modifications included medical nutrition therapy and physical exercise recommendations. Anti-diabetic medications included either oral treatment with metformin or glyburide and\or insulin.

RESULTS

Women in the lifestyle modifications group were younger (32.87 vs. 33.79 years, p = 0.012) and had lower pre-pregnancy body-mass-index (25.86 vs. 27.93 kg/m², p < 0.001). Glucose challenge test (GCT) was significantly lower in the lifestyle modifications group (158.31 vs. 171.04 mg/dL in the anti-diabetic treatment group, p < 0.001). Moreover, fasting oral-glucose-tolerance-test (fOGTT) results were significantly lower in the lifestyle modifications group (88.22 vs. 96.34 mg/dL in the anti-diabetic treatment group, p < 0.001). In a receiver-operator-curve analysis, GCT + 4*fOGTT, was the best model to predict lifestyle modifications failure with an area under the curve of 0.7419. Higher rates of vaginal delivery and lower rates of maternal hypoglycemia in the lifestyle modifications group were observed.

CONCLUSIONS

Maternal baseline characteristics and diabetes diagnostic parameters may predict which women will fail to achieve good glycemic control solely by lifestyle modifications.

Glucose Lowering Treatment Modalities of Type 2 Diabetes Mellitus

This chapter gives an overview of present knowledge and clinical aspects of antidiabetic drugs according to the recently available research evidence and clinical expertise.Many agents are acting on eight groups of pathophysiological mechanisms, which is commonly called as "Ominous Octet" by DeFronzo. The muscle, liver and β-cell, the fat cell, gastrointestinal tract, α-cell, kidney, and brain play essential roles in the development of glucose intolerance in type 2 diabetic individuals (Defronzo, Diabetes 58:773-795, 2009).A treatment paradigm shift is seen in the initiation of anti-hyperglycemic agents from old friends (meglitinides or sulphonylürea) to newer agents effecting on GLP-1 RA or SGLT-2 inhibitors. It is mostly about the other protective positive effects of these agents for kidney, heart, etc. Although there are concerns for the long term safety profiles; they are used widely around the World. The delivery of patient-centered care, facilitating medication adherence, the importance of weight loss in obese patients, the importance of co-morbid conditions are the mainstays of selecting the optimal agent.

No evidence of attenuation of placental insulin-stimulated Akt phosphorylation and amino acid transport in maternal obesity and gestational diabetes mellitus

Pregnancies complicated by obesity and/or gestational diabetes (GDM) are associated with peripheral insulin resistance; however, the insulin responsiveness of the placenta in these pregnancy complications remains largely unknown. We tested the hypothesis that primary human trophoblast cells and placental villous explants will be insulin responsive, characterized by amino acid transport, Akt and Erk activity with maternal obesity, and/or GDM. We evaluated term placentas from women with normal body mass index (BMI) (normal; n = 15), obesity (OB; n = 11), normal BMI with GDM (N-GDM; n = 11), and obesity with GDM (OB-GDM; n = 11). In a subgroup, primary human trophoblast cells (PHT) were isolated, and in an independent subgroup placental villous explants were exposed to varying concentrations of insulin. Amino acid transport capacity and insulin signaling activity were determined. Insulin significantly increased amino acid transport activity to a similar degree in PHT cells isolated from normal (+21%), N-GDM (+38%), OB (+37%), and OB-GDM (+35%) pregnancies. Insulin increased Akt and Erk phosphorylation in PHT cells (3-fold) and in villous explants (2-fold) in all groups to a similar degree. In contrast to the peripheral maternal insulin resistance commonly associated with obesity and/or GDM, we found that the placenta is insulin sensitive in these pregnancy complications. We suggest that elevated maternal insulin levels in pregnancies complicated by obesity and/or GDM promote critical placental functions, including amino acid transport. Insulin-stimulated placental nutrient delivery may contribute to the increased risk of fetal overgrowth and adiposity in these pregnancies. Moreover, our findings may inform efforts to optimize insulin regimens for women with GDM.

Neonatal, infant, and childhood growth following metformin versus insulin treatment for gestational diabetes: A systematic review and meta-analysis

BACKGROUND

Metformin is increasingly offered as an acceptable and economic alternative to insulin for treatment of gestational diabetes mellitus (GDM) in many countries. However, the impact of maternal metformin treatment on the trajectory of fetal, infant, and childhood growth is unknown.

METHODS AND FINDINGS

PubMed, Ovid Embase, Medline, Web of Science, ClinicalTrials.gov, and the Cochrane database were systematically searched (from database inception to 26 February 2019). Outcomes of GDM-affected pregnancies randomised to treatment with metformin versus insulin were included (randomised controlled trials and prospective randomised controlled studies) from cohorts including European, American, Asian, Australian, and African women. Studies including pregnant women with pre-existing diabetes or non-diabetic women were excluded, as were trials comparing metformin treatment with oral glucose-lowering agents other than insulin. Two reviewers independently assessed articles for eligibility and risk of bias, and conflicts were resolved by a third reviewer. Outcome measures were parameters of fetal, infant, and childhood growth, including weight, height, BMI, and body composition. In total, 28 studies (n = 3,976 participants) met eligibility criteria and were included in the meta-analysis. No studies reported fetal growth parameters; 19 studies (n = 3,723 neonates) reported measures of neonatal growth. Neonates born to metformin-treated mothers had lower birth weights (mean difference -107.7 g, 95% CI -182.3 to -32.7, I2 = 83%, p = 0.005) and lower ponderal indices (mean difference -0.13 kg/m3, 95% CI -0.26 to 0.00, I2 = 0%, p = 0.04) than neonates of insulin-treated mothers. The odds of macrosomia (odds ratio [OR] 0.59, 95% CI 0.46 to 0.77, p < 0.001) and large for gestational age (OR 0.78, 95% CI 0.62 to 0.99, p = 0.04) were lower following maternal treatment with metformin compared to insulin. There was no difference in neonatal height or incidence of small for gestational age between groups. Two studies (n = 411 infants) reported measures of infant growth (18-24 months of age). In contrast to the neonatal phase, metformin-exposed infants were significantly heavier than those in the insulin-exposed group (mean difference 440 g, 95% CI 50 to 830, I2 = 4%, p = 0.03). Three studies (n = 520 children) reported mid-childhood growth parameters (5-9 years). In mid-childhood, BMI was significantly higher (mean difference 0.78 kg/m2, 95% CI 0.23 to 1.33, I2 = 7%, p = 0.005) following metformin exposure than following insulin exposure, although the difference in absolute weights between the groups was not significantly different (p = 0.09). Limited evidence (1 study with data treated as 2 cohorts) suggested that adiposity indices (abdominal [p = 0.02] and visceral [p = 0.03] fat volumes) may be higher in children born to metformin-treated compared to insulin-treated mothers. Study limitations include heterogeneity in metformin dosing, heterogeneity in diagnostic criteria for GDM, and the scarcity of reporting of childhood outcomes.

CONCLUSIONS

Following intrauterine exposure to metformin for treatment of maternal GDM, neonates are significantly smaller than neonates whose mothers were treated with insulin during pregnancy. Despite lower average birth weight, metformin-exposed children appear to experience accelerated postnatal growth, resulting in heavier infants and higher BMI by mid-childhood compared to children whose mothers were treated with insulin. Such patterns of low birth weight and postnatal catch-up growth have been reported to be associated with adverse long-term cardio-metabolic outcomes. This suggests a need for further studies examining longitudinal perinatal and childhood outcomes following intrauterine metformin exposure. This review protocol was registered with PROSPERO under registration number CRD42018117503.

Gestational diabetes mellitus

Hyperglycaemia that develops during pregnancy and resolves after birth has been recognized for over 50 years, but uniform worldwide consensus is lacking about threshold hyperglycaemic levels that merit a diagnosis of 'gestational diabetes mellitus' (GDM) and thus treatment during pregnancy. GDM is currently the most common medical complication of pregnancy, and prevalence of undiagnosed hyperglycaemia and even overt diabetes in young women is increasing. Maternal overweight and obesity, later age at childbearing, previous history of GDM, family history of type 2 diabetes mellitus and ethnicity are major GDM risk factors. Diagnosis is usually performed using an oral glucose tolerance test (OGTT), although a non-fasting, glucose challenge test (GCT) is used in some parts of the world to screen women for those requiring a full OGTT. Dietary modification and increased physical activity are the primary treatments for GDM, but pharmacotherapy, usually insulin, is used when normoglycaemia is not achieved. Oral hypoglycaemic agents, principally metformin and glibenclamide (glyburide), are also used in some countries. Treatment improves immediate pregnancy outcomes, reducing excess fetal growth and adiposity and pregnancy-related hypertensive disorders. GDM increases the risk of long-term complications, including obesity, impaired glucose metabolism and cardiovascular disease, in both the mother and infant. Optimal management of mother and infant during long-term follow-up remains challenging, with very limited implementation of preventive strategies in most parts of the world.

Drugs to Control Diabetes During Pregnancy

Diabetes is a common complication of pregnancy associated with both short- and long-term adverse maternal and offspring effects. All types of diabetes in pregnancy are increasing in prevalence. Treatment of diabetes in pregnancy, targeting glycemic control, improves both maternal and offspring outcomes, albeit imperfectly for many women. Pharmacologic treatment recommendations differ between pregestational and gestational diabetes. Improved treatment of diabetes in pregnancy will need to consider maternal disease heterogeneity and comorbidities as well as long-term offspring outcomes. In this review, the authors summarize recent clinical studies to highlight established pharmacologic treatments for diabetes in pregnancy and provide suggestions for further research.

Metformin and Breast Cancer: Molecular Targets

Metformin has been the first-line drug for the treatment of type II diabetes mellitus for decades, being presently the most widely prescribed antihyperglycemic drug. Retrospective studies associate the use of metformin with a reduction in cancer incidence and cancer-related death. However, despite extensive research about the molecular effects of metformin in cancer cells, its mode of action remains controversial. The major molecular targets of metformin include complex I of the mitochondrial electron transport chain, adenosine monophosphate (AMP)-activated protein kinase (AMPK), and mechanistic target of rapamycin complex 1 (mTORC1), but AMPK-independent effects of metformin have also been described. Breast cancer is one of the leading causes of cancer-related morbidity and mortality among women worldwide. Several studies have reinforced a link between breast cancer risk and diabetes. Moreover, metformin significantly reduces breast cancer risk, compared to patients who are not using metformin and is independent of diabetes status. In this review, we summarize the current molecular evidence to elucidate metformin's mode of action against breast cancer cells.