The Role of Metformin in Metabolic Disturbances during Pregnancy: Polycystic Ovary Syndrome and Gestational Diabetes Mellitus

Pre-eclampsia: Re-visiting pathophysiology, role of immune cells, biomarker identification and recent advances in its management

Pre-eclampsia (PE) is a hypertension condition that occurs exclusively during pregnancy and has the potential to impact nearly all organ systems. It is estimated to complicate approximately 2-8% of pregnancies worldwide. PE is a prominent medical disorder that poses a significant risk to pregnant mothers and their infants. This review commences by giving the most up-to- date concepts about the pathophysiology of PE. The condition involves atypical infiltration of trophoblast cells into the spiral arteries of the decidua and myometrium, resulting in an insufficient establishment of proper blood flow between the uterus and placenta. The aberrant activation of natural killer (NK) cells in both the peripheral blood and the decidua has been identified as one of the contributing factors to the development of PE. The strong evidence for the genetic etiology of PE is provided by the association between maternal killer cell immunoglobulin-like receptor (KIR) and Human Leukocyte Antigen (HLA-C) in trophoblast cells. Recent observations provide evidence that changes in the expression of anti-angiogenic factors in the placenta are the underlying cause of the clinical symptoms associated with the condition. This review also provides a comprehensive overview of the latest advancements in understanding the underlying causes of PE. It specifically highlights the emergence of new diagnostic biomarkers and their potential implications for therapeutic interventions in managing this medical condition.

Metformin: new applications for an old drug

Metformin is a biguanide, evolved as one of the most widely used medicines. The applications of this component include but are not limited to reducing blood glucose, weight loss, and polycystic ovary syndrome. Studies about other probable indications have emerged, indicating that this agent can also be utilized for other purposes. In this review, applications of metformin are noticed based on the current evidence. Metformin commonly is used as an off-label drug in non-alcoholic fatty liver disease (NAFLD), but it worsens inflammation and should not be used for this purpose, according to the latest research. Metformin decreased the risk of death in patients with liver cirrhosis. It is an effective agent in the prevention and improvement of survival in patients suffering hepatocellular carcinoma. There is evidence of the beneficial effects of metformin in colorectal cancer, early-stage prostate cancer, breast cancer, urothelial cancer, blood cancer, melanoma, and bone cancer, suggesting metformin as a potent anti-tumor agent. Metformin shows neuroprotective effects and provides a potential therapeutic benefit for mild cognitive impairment and Alzheimer's disease (AD). It also has been shown to improve mental function and reduce the incidence of dementia. Another condition that metformin has been shown to slow the progression of is Duchenne muscular dystrophy. Regarding infectious diseases, tuberculosis (TB) and coronavirus disease (COVID-19) are among the conditions suggested to be affected by metformin. The beneficial effects of metformin in cardiovascular diseases were also reported in the literature. Concerning renal function, studies showed that daily oral administration of metformin could ameliorate kidney fibrosis and normalize kidney structure and function. This study reviewed the clinical and preclinical evidence about the possible benefits of metformin based on recent studies. Numerous questions like whether these probable indications of metformin can be observed in non-diabetics, need to be described by future basic experiments and clinical studies.

Putative Complementary Compounds to Counteract Insulin-Resistance in PCOS Patients

Polycystic ovary syndrome (PCOS) is the most frequent endocrine-metabolic disorder among women at reproductive age. The diagnosis is based on the presence of at least two out of three criteria of the Rotterdam criteria (2003). In the last decades, the dysmetabolic aspect of insulin resistance and compensatory hyperinsulinemia have been taken into account as the additional key features in the etiopathology of PCOS, and they have been widely studied. Since PCOS is a complex and multifactorial syndrome with different clinical manifestations, it is difficult to find the gold standard treatment. Therefore, a great variety of integrative treatments have been reported to counteract insulin resistance. PCOS patients need a tailored therapeutic strategy, according to the patient’s BMI, the presence or absence of familiar predisposition to diabetes, and the patient’s desire to achieve pregnancy or not. The present review analyzes and discloses the main clinical insight of such complementary substances.

Tumor targetable and pH-sensitive polymer nanoparticles for simultaneously improve the Type 2 Diabetes Mellitus and malignant breast cancer

In the recent study, we have developed novel tumor targetable and pH-sensitive PLGA nanoparticles co-loaded with camptothecin (CPT) and metformin (Metf) to simultaneously improve the Type 2 Diabetes Mellitus (T2DM) and malignant breast cancer. To improve the drug loading efficiency, the hydrophobic CPT was conjugated with PLGA polymer by the pH-sensitive hydrazone bonds (hyd). Then, the Metf was physically loaded into the hydrophobicity inner core of CPT-conjugated PLGA nanocomplex to form the dual drugs-loaded nanoparticles (NP/CPT-Metf). Furthermore, on the surface of NP/CPT-Metf was modified with tumor-homing CGKRK peptides to obtain the tumor targetable and pH-sensitive polymer nanoparticles (CNP/CPT-Metf). It was demonstrated that the developed CNP/CPT-Metf displayed sufficient sensitivity to the weak acidic tumor microenvironment. Besides, excellent ability of CNP/CPT-Metf to mediate accumulation of drugs in cells and tumor tissues finally in turn resulted in a signal enhanced anti-tumor effect. Furthermore, it was demonstrated as well that CNP/CPT-Metf was able of significantly alleviating the type 2 diabetes mellitus in diabetic mice. In summary, the developed multifunctional polymer nanoparticles might represent a promising strategy for simultaneously improve the T2DM and treat malignant breast cancer.

Gestational Diabetes Mellitus: The Crosslink among Inflammation, Nitroxidative Stress, Intestinal Microbiota and Alternative Therapies

Gestational diabetes mellitus (GDM) is characterized by a set of metabolic complications arising from adaptive failures to the pregnancy period. Estimates point to a prevalence of 3 to 15% of pregnancies. Its etiology includes intrinsic and extrinsic aspects of the progenitress, which may contribute to the pathophysiogenesis of GDM. Recently, researchers have identified that inflammation, oxidative stress, and the gut microbiota participate in the development of the disease, with potentially harmful effects on the health of the maternal-fetal binomial, in the short and long terms. In this context, alternative therapies were investigated from two perspectives: the modulation of the intestinal microbiota, with probiotics and prebiotics, and the use of natural products with antioxidant and anti-inflammatory properties, which may mitigate the endogenous processes of the GDM, favoring the health of the mother and her offspring, and in a future perspective, alleviating this critical public health problem.

Association of metabolic and inflammatory markers with polycystic ovarian syndrome (PCOS): an update

BACKGROUND

Polycystic ovarian syndrome (PCOS) is the most prevalent metabolic disorder in reproductive-age women. It is indeed a multifactorial condition evidenced by ovarian dysfunction, hyperandrogenaemia, infertility, hormonal imbalance and chronic anovulation. Experimental evidence infers that PCOS women are prone to cardiovascular problems and insulin resistance.

PURPOSE

To furnish the details about the association of inflammatory markers in PCOS.

DESIGN

An extensive literature search on PubMed, science direct and google scholar has been performed for articles about PCOS and inflammation in PCOS. A comprehensive analysis using original articles, reviews, systemic and meta-analysis was conducted for better understanding the relationship between inflammatory cytokines and PCOS.

RESULTS

The inflammatory markers perform a substantial part in managing the functions of the ovary. Any disturbances in their levels can lead to ovarian dysfunction. Inflammatory markers are associated with PCOS pathogenesis. The interplay between inflammatory cytokines in the PCOS ovary strongly implies that inflammation is one of the most potent risk factors of PCOS.

CONCLUSION

Inflammatory markers have a significant role in regulating the ovary. This manuscript highlights the significance of metabolic and inflammatory markers with PCOS. Since PCOS is always considered as a metabolic disorder, researchers can also consider focusing on the relationship between the inflammatory markers in PCOS to establish a new treatment or management of the disease and to improve women's health.

Improvement Effect of Metformin on Female and Male Reproduction in Endocrine Pathologies and Its Mechanisms

Metformin (MF), a first-line drug to treat type 2 diabetes mellitus (T2DM), alone and in combination with other drugs, restores the ovarian function in women with polycystic ovary syndrome (PCOS) and improves fetal development, pregnancy outcomes and offspring health in gestational diabetes mellitus (GDM) and T2DM. MF treatment is demonstrated to improve the efficiency of in vitro fertilization and is considered a supplementary drug in assisted reproductive technologies. MF administration shows positive effect on steroidogenesis and spermatogenesis in men with metabolic disorders, thus MF treatment indicates prospective use for improvement of male reproductive functions and fertility. MF lacks teratogenic effects and has positive health effect in newborns. The review is focused on use of MF therapy for restoration of female and male reproductive functions and improvement of pregnancy outcomes in metabolic and endocrine disorders. The mechanisms of MF action are discussed, including normalization of metabolic and hormonal status in PCOS, GDM, T2DM and metabolic syndrome and restoration of functional activity and hormonal regulation of the gonadal axis.

Expression of mitofusin 2 in placentae of women with gestational diabetes mellitus

Gestational diabetes mellitus (GDM) represents a common carbohydrate metabolism disorder during pregnancy. The objective of this study was to evaluate the expression levels of mitofusin 2 (MFN2) expression in placentae of GDM patients compared to that in the placental tissues from normal uncomplicated pregnancies. A total of 70 subjects were enrolled from September 2014 to June 2016, including 42 patients with GDM (the GDM group) and 28 normal uncomplicated pregnancies (the control group). Immunohistochemical staining and qRT-PCR were used for the detection of the expression levels and distribution of MFN2 in the placentae of GDM patients and normal controls. Kolmogorov-Smirnov test was used for statistical analysis. P < 0.05 and P < 0.01 were used for assessing statistical significance. The baseline characteristics were comparable in both groups. The 1-h and 2-h postprandial glucose levels (PPG) were 7.94±1.26 versus 6.88±0.51 mmol/L and 7.01±1.34 versus 6.14±0.63 mmol/L, respectively,for the GDM group and the control group (P < 0.05). The relative expression levels of MFN2 mRNA were 0.982±1.242 for GDM and 1.257 ± 0.815 for control, respectively, with significant between group difference (P < 0.01). Immunohistochemical staining analysis showed that MFN2 was mostly distributed in the cytoplasm of syncytiotrophoblasts under optical microscopy. Additionally,about 50% of samples of the GDM group were within the intensity of moderate staining of MFN2 and more than 50% of patients in the control group were within the intensity of strong staining of MFN2. The expression levels of MFN2 in GDM placentae was significantly lower compared to that of placentae from normal uncomplicated pregnancies.

Why AMPK agonists not known to be stressors may surprisingly contribute to miscarriage or hinder IVF/ART

Here we examine recent evidence suggesting that many drugs and diet supplements (DS), experimental AMP-activated protein kinase (AMPK) agonists as well as energy-depleting stress, lead to decreases in anabolism, growth or proliferation, and potency of cultured oocytes, embryos, and stem cells in an AMPK-dependent manner. Surprising data for DS and drugs that have some activity as AMPK agonists in in vitro experiments show possible toxicity. This needs to be balanced against a preponderance of evidence in vivo that these drugs and DS are beneficial for reproduction. We here discuss and analyze data that leads to two possible conclusions: First, although DS and drugs that have some of their therapeutic mechanisms mediated by AMPK activity associated with low ATP levels, some of the associated health problems in vivo and in vitro fertilization/assisted reproductive technologies (IVF/ART) may be better-treated by increasing ATP production using CoQ10 (Ben-Meir et al., Aging Cell 14:887-895, 2015). This enables high developmental trajectories simultaneous with solving stress by energy-requiring responses. In IVF/ART, it is ultimately best to maintain handling and culture of gametes and embryos in the quietest state with low metabolic activity (Leese et al., Mol Hum Reprod 14:667-672, 2008; Leese, Bioessays 24 (9):845-849, 2002) using back-to-nature or simplex algorithms to identify optima (Biggers, Reprod Biomed Online 4 Suppl 1:30-38, 2002). Stress markers, such as checkpoint proteins like TRP53 (aka p53) (Ganeshan et al., Exp Cell Res 358:227-233, 2017); Ganeshan et al., Biol Reprod 83:958-964, 2010) and a small set of kinases from the protein kinome that mediate enzymatic stress responses, can also be used to define optima. But, some gametes or embryos may have been stressed in vivo prior to IVF/ART or IVF/ART optimized for one outcome may be suboptimal for another. Increasing nutrition or adding CoQ10 to increase ATP production (Yang et al., Stem Cell Rev 13:454-464, 2017), managing stress enzyme levels with inhibitors (Xie et al., Mol Hum Reprod 12:217-224, 2006), or adding growth factors such as GM-CSF (Robertson et al., J Reprod Immunol 125:80-88, 2018); Chin et al., Hum Reprod 24:2997-3009, 2009) may increase survival and health of cultured embryos during different stress exposure contexts (Puscheck et al., Adv Exp Med Biol 843:77-128, 2015). We define "stress" as negative stimuli which decrease normal magnitude and speed of development, and these can be stress hormones, reactive oxygen species, inflammatory cytokines, or physical stimuli such as hypoxia. AMPK is normally activated by high AMP, commensurate with low ATP, but it was recently shown that if glucose is present inside the cell, AMPK activation by low ATP/high AMP is suppressed (Zhang et al., Nature 548:112-116, 2017). As we discuss in more detail below, this may also lead to greater AMPK agonist toxicity observed in two-cell embryos that do not import glucose. Stress in embryos and stem cells increases AMPK in large stimulation indexes but also direness indexes; the fastest AMPK activation occurs when stem cells are shifted from optimal oxygen to lower or high levels (Yang et al., J Reprod Dev 63:87-94, 2017). CoQ10 use may be better than risking AMPK-dependent metabolic and developmental toxicity when ATP is depleted and AMPK activated. Second, the use of AMPK agonists, DS, and drugs may best be rationalized when insulin resistance or obesity leads to aberrant hyperglycemia and hypertriglyceridemia, and obesity that negatively affect fertility. Under these conditions, beneficial effects of AMPK on increasing triglyceride and fatty acid and glucose uptake are important, as long as AMPK agonist exposures are not too high or do not occur during developmental windows of sensitivity. During these windows of sensitivity suppression of anabolism, proliferation, and stemness/potency due to AMPK activity, or overexposure may stunt or kill embryos or cause deleterious epigenetic changes.

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.

Prenatal androgen exposure causes hypertension and gut microbiota dysbiosis

BACKGROUND

Conditions of excess androgen in women, such as polycystic ovary syndrome (PCOS), often exhibit intergenerational transmission. One way in which the risk for PCOS may be increased in daughters of affected women is through exposure to elevated androgens in utero. Hyperandrogenemic conditions have serious health consequences, including increased risk for hypertension and cardiovascular disease. Recently, gut dysbiosis has been found to induce hypertension in rats, such that blood pressure can be normalized through fecal microbial transplant. Therefore, we hypothesized that the hypertension seen in PCOS has early origins in gut dysbiosis caused by in utero exposure to excess androgen. We investigated this hypothesis with a model of prenatal androgen (PNA) exposure and maternal hyperandrogenemia by single-injection of testosterone cypionate or sesame oil vehicle (VEH) to pregnant dams in late gestation. We then completed a gut microbiota and cardiometabolic profile of the adult female offspring.

RESULTS

The metabolic assessment revealed that adult PNA rats had increased body weight and increased mRNA expression of adipokines: adipocyte binding protein 2, adiponectin, and leptin in inguinal white adipose tissue. Radiotelemetry analysis revealed hypertension with decreased heart rate in PNA animals. The fecal microbiota profile of PNA animals contained higher relative abundance of bacteria associated with steroid hormone synthesis, Nocardiaceae and Clostridiaceae, and lower abundance of Akkermansia, Bacteroides, Lactobacillus, Clostridium. The PNA animals also had an increased relative abundance of bacteria associated with biosynthesis and elongation of unsaturated short chain fatty acids (SCFAs).

CONCLUSIONS

We found that prenatal exposure to excess androgen negatively impacted cardiovascular function by increasing systolic and diastolic blood pressure and decreasing heart rate. Prenatal androgen was also associated with gut microbial dysbiosis and altered abundance of bacteria involved in metabolite production of short chain fatty acids. These results suggest that early-life exposure to hyperandrogenemia in daughters of women with PCOS may lead to long-term alterations in gut microbiota and cardiometabolic function.

Effects of myo-inositol plus alpha-lactalbumin in myo-inositol-resistant PCOS women

Background

Myo-inositol (MI), successfully used in polycystic ovary syndrome (PCOS), was administered with α-LA to exploit its action of favouring the passage of other molecules through biological barriers, and also considering its anti-inflammatory effect.

Methods

PCOS patients, according to the Rotterdam ESHRE–ASRM criteria, with anovulation and infertility > 1 year, were included in this open and prospective study. The preliminary phase was aimed at determining a set of MI-resistant PCOS patients. This treatment involved 2 g MI, taken twice per day by oral route, for three months. The Homeostasis Model Assessment (HOMA) index and MI plasma levels were measured. In the main phase, previously selected MI-resistant patients received the same daily amount of MI plus 50 mg α-LA twice a day, for a further three months. Ovulation was assessed using ultrasound examination on days 12, 14 and 20 of the cycle. The HOMA index, lipid, hormone and MI plasma levels were detected at baseline and at the end of this phase.

Results

Thirty-seven anovulatory PCOS subjects were included in the study. Following MI treatment, 23 of the 37 women (62%) ovulated, while 14 (38%) were resistant and did not ovulate. In the latter group, MI plasma levels did not increase. These MI-resistant patients underwent treatment in the main phase of the study, receiving MI and α-LA. After this combined treatment, 12 (86%) of them ovulated. Their MI plasma levels were found to be significantly higher than at baseline; also, a hormone and lipid profile improvement was recorded.

Conclusion

The combination of MI with α-LA allowed us to obtain significant progress in the treatment of PCOS MI-resistant patients. Therefore, this new formulation was able to re-establish ovulation, greatly increasing the chances of desired pregnancy.

Trial Registration

Clinical trial registration number: NCT03422289 (ClinicalTrials.gov registry).

A Review on Glycosylated Hemoglobin in Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is one of the most common reproductive endocrine disorders among women of reproductive age, with a variety of complications and consequences mostly due to hyperandrogenism and insulin resistance (IR). PCOS patients with IR are at risk for metabolic syndrome and diabetes mellitus (DM) along with its complications such as cardiovascular events. There are several methods for screening IR in patients with PCOS to predict DM and other complications. Fasting plasma glucose test, oral glucose tolerance test, and insulin and glycosylated hemoglobin (HbA1c) levels are some available screening tools for IR. The American Diabetes Association recommended HbA1c to screen for DM because HbA1c is not affected by day-to-day plasma glucose levels and reflects the plasma glucose status during 2-3 months before measurement. Some studies have evaluated the role of HbA1c as a screening method to predict DM in PCOS patients, however, there are still controversies in this matter. Also some studies reported that HbA1c has a correlation with complications of PCOS such as metabolic syndrome and cardiovascular events. We found that HbA1c could be a suitable screening test for IR in PCOS patients but more studies are recommended, omitting confounding factors that could affect IR in patients with PCOS, such as antihyperglycemic agents like metformin, or lifestyle modification, which can be effective in reducing IR in patients with PCOS.