Long-term functional alterations following prenatal GLP-1R activation

Considering the use of GLP-1 receptor agonists in women with obesity prior to pregnancy: a narrative review

PURPOSE

Metabolic disease, including obesity and type 2 diabetes, are amongst the most significant health issues facing women of reproductive age. To date, no antenatal weight management tools have reduced the risk of adverse health outcomes for women with obesity and their offspring, resulting in a shift in focus to the pre-conception period. Although not yet recognised in most international weight management guidelines, glucagon-like peptide-1 receptor agonists (GLP-1 RAs) are being increasingly used for weight management prior to conception.

METHODS

A literature search of PubMed, Medline, and Embase databases identified relevant articles describing the use of GLP-1 RAs prior to and during pregnancy. Papers were selected based on relevance and originality, with clinical trials, large observational studies and meta-analyses being preferentially included.

RESULTS

This narrative review summarises the mechanism of action of GLP-1 RAs and the clinical effects observed in non-pregnant adults. It synthesises the available data from human and animal studies regarding the safety and efficacy of GLP-1 RAs prior to pregnancy, and the consequences of inadvertent drug exposure in early pregnancy. In considering the need to balance the risks of metabolic disease with the risks posed by inadvertent drug exposure, it highlights the areas where further research is needed to guide clinical decision-making.

CONCLUSION

GLP-1 RAs may have a role in facilitating weight loss and improving the metabolic health of women prior to pregnancy. However, there is currently insufficient evidence to demonstrate that the use of this class of drugs prior to pregnancy improves pregnancy outcomes.

Teratogenic risks of treated and untreated maternal obesity

Untreated obesity in pregnancy is associated with adverse fetal and neonatal outcomes that influence the long-term offspring health trajectory, propagating obesity and cardiometabolic disease from one generation to the next. The current efforts to reduce the risk of these negative outcomes through preconception weight loss remain largely ineffective. Anti-obesity medications (AOMs) are an understudied option for this indication, likely due to the potential for teratogenicity with accidental exposure during pregnancy. However, the current recommendation to discontinue all AOMs prior to conception fails to frame obesity within the chronic disease paradigm typically used for preconception counseling. Evolving evidence suggests that glucagon-like peptide 1 receptor agonists (GLP-1 RAs), the newest and most effective AOM class, may be safe in early pregnancy. Although further research is needed, counseling about GLP-1 RAs during pregnancy should include the potential for both risk and benefit. This review summarizes the known risks that obesity in pregnancy poses to the offspring and discusses the benefits and limitations of current treatment strategies. While there remain several barriers to optimal preconception and prenatal care for people with obesity, this review aims to arm providers with the knowledge needed for patient-centered counseling prior to and during pregnancy.

Impact on Metabolism Generated by Surgical and Pharmacological Interventions for Weight Loss in Women with Infertility

Obesity increases the risk of anovulation, insulin resistance, hyperandrogenism, and endometrial dysfunction, resulting in women with infertility and increasing preconceptional and pregnancy complications. Bariatric surgery has been described as the most effective intervention for obesity, with improved fertility outcomes. However, its invasive nature increases the potential of nutritional deficiencies and the need for a delayed conception post-surgery. On the other hand, pharmacological treatments such as glucagon-like-peptide 1 receptor agonists offer non-invasive alternatives with promising results in body weight, improving insulin sensitivity and restoring ovarian function. However, their use must be discontinued before conception due to potential fetal risks. Other available pharmacological treatment options encompass topiramate, phentermine, and Orlistat. The choice of treatment must be individualized considering cost-effectiveness, accessibility, obesity severity, reproductive goals, and associated risks within each patient. A multidisciplinary approach is essential to optimize metabolic and reproductive health in obesity and infertility. This review will examine the impact on metabolism when comparing surgical and pharmacological interventions for weight loss in women with infertility.

Preventing maternal morbidity and mortality from preeclampsia and eclampsia particularly in low- and middle-income countries

Preeclampsia (PE) is a complex heterogeneous disorder with overlapping clinical phenotypes that complicate diagnosis and management. Although several pathophysiological mechanisms have been proposed, placental dysfunction due to inadequate remodelling of uterine spiral arteries leading to mal-perfusion and syncytiotrophoblast stress is recognized as the unifying characteristic of early-onset PE. Placental overgrowth and or premature senescence are probably the causes of late-onset PE. The frequency of PE has increased over the last few decades due to population-wide increases in risk factors viz. obesity, diabetes, multifetal pregnancies and pregnancies at an advanced maternal age. Whilst multimodal tools with components comprising risk factors, biomarkers and sonography are used for predicting PE, aspirin is most effective in preventing early-onset PE. The incidence and clinical consequences of PE and eclampsia are influenced by socioeconomic and cultural factors, therefore management strategies should involve multi-sector partnerships to mitigate the adverse outcomes.

Insulin-sensitizing agents for infertility treatment in woman with polycystic ovary syndrome: a narrative review of current clinical practice

PURPOSE

Polycystic ovary syndrome (PCOS) is an endocrine, metabolic, and reproductive disorder which, according to the Rotterdam criteria, affects up to 24% of women of childbearing age. Although the prevalence of infertility in this subpopulation of women is high, the optimal treatment has not been fully established yet. Insulin resistance is considered to be an important mechanism involved in the development of PCOS; hence, the aim of this narrative review is to present an overview of the current pharmacological insulin-sensitizing treatment modalities for infertile women with PCOS.

METHODS

A MEDLINE and PubMed search for the years 1990-2023 was performed using a combination of keywords. Clinical trials with insulin sensitizers used for infertility treatment as well as analyses of systematic reviews and meta-analyses were evaluated. When deemed necessary, additional articles referenced in the retrieved papers were included in this narrative review.

RESULTS

Several insulin-sensitizing compounds and various therapeutical protocols are available for infertility treatment of women with PCOS. Metformin is the most common adjuvant medication to induce ovulation in infertile women with PCOS and is more frequently administered in combination with clomiphene citrate than on its own. Recently, inositol and glucagon-like peptide-1 (GLP-1) receptor agonists have emerged as possible options for infertility treatment in PCOS.

CONCLUSION

The future of medical treatment of PCOS women with infertility lies in a personalized pharmacological approach, which involves various compounds with different mechanisms of action that could modify ovarian function and endometrial receptivity, ultimately leading to better overall reproductive outcomes in these women.

Case Series: Exposure to Glucagon-like Peptide-1 Receptor Agonist in the First Trimester of Pregnancy in Two Siblings

BACKGROUND

The safety of glucagon-like peptide-1 receptor agonists in pregnancy is under investigation. In this report, we want to share the results of a patient with polycystic ovary syndrome who applied to our outpatient clinic for diabetes and had two unplanned pregnancies following the initiation of exenatide for obesity treatment.

CASE PRESENTATION

A 40-year-old woman with diabetes was admitted to the endocrinology outpatient clinic. On physical examination, the body mass index was over 35 kg/m ², therefore, exenatide treatment was started. Four weeks later, she came to suspicion of pregnancy, and obstetric ultrasound revealed a fetus at 17 weeks of gestation. Exenatide was interrupted. At 37 weeks of gestation, she gave birth to a female baby with atrial septal defect. The baby was followed with echocardiography annually until spontaneous closure of ASD when she was three years old. Two years later, the patient consulted us again for weight gain. Exenatide was prescribed again. After 5 months, an abdominal ultrasound revealed a fatty liver and detected a pregnancy compatible with 13 weeks of gestation. Two siblings are healthy now, 7 and 5 years old, respectively.

CONCLUSION

This report contributes to our knowledge of fetal exposure to exenatide. Large-scale randomized studies are needed for its safe use in pregnancy.

Glucagon-like peptide-1 receptor agonists and safety in the preconception period

PURPOSE OF REVIEW

Glucagon-like peptide-1 (GLP-1) receptor agonists (RAs) are becoming increasingly popular for the treatment of type II diabetes and obesity. Body mass index (BMI) thresholds at in vitro fertilization (IVF) clinics may further drive the use of these medications before infertility treatment. However, most clinical guidance regarding optimal time to discontinue these medications prior to conception is based on animal data. The purpose of this review was to evaluate the literature for evidence-based guidance regarding the preconception use of GLP-1 RA.

RECENT FINDINGS

16 articles were found in our PubMed search, 10 were excluded as they were reviews or reported on animal data. Included were 3 case reports detailing pregnancy outcomes in individual patients that conceived while on a GLP-1 RA and 2 randomized controlled trials (RCTs) and a follow-up study to one of the RCTs that reported on patients randomized to GLP-1 RA or metformin prior to conception. No adverse pregnancy or neonatal outcomes were reported.

SUMMARY

There are limited data from human studies to guide decision-making regarding timing of discontinuation of GLP-1 RA before conception. Studies focused on pregnancy and neonatal outcomes would provide additional information regarding a safe washout period. Based on the available literature a 4-week washout period prior to attempting conception may be considered for the agents reviewed in this publication.

Bile acid signalling and its role in anxiety disorders

Anxiety disorder is a prevalent neuropsychiatric disorder that afflicts 7.3%~28.0% of the world's population. Bile acids are synthesized by hepatocytes and modulate metabolism via farnesoid X receptor (FXR), G protein-coupled receptor (TGR5), etc. These effects are not limited to the gastrointestinal tract but also extend to tissues and organs such as the brain, where they regulate emotional centers and nerves. A rise in serum bile acid levels can promote the interaction between central FXR and TGR5 across the blood-brain barrier or activate intestinal FXR and TGR5 to release fibroblast growth factor 19 (FGF19) and glucagon-like peptide-1 (GLP-1), respectively, which in turn, transmit signals to the brain via these indirect pathways. This review aimed to summarize advancements in the metabolism of bile acids and the physiological functions of their receptors in various tissues, with a specific focus on their regulatory roles in brain function. The contribution of bile acids to anxiety via sending signals to the brain via direct or indirect pathways was also discussed. Different bile acid ligands trigger distinct bile acid signaling cascades, producing diverse downstream effects, and these pathways may be involved in anxiety regulation. Future investigations from the perspective of bile acids are anticipated to lead to novel mechanistic insights and potential therapeutic targets for anxiety disorders.

Effects of GLP-1 agonists and SGLT2 inhibitors during pregnancy and lactation on offspring outcomes: a systematic review of the evidence

Aims/hypothesis

Glucagon-like peptide 1 (GLP-1) agonists and sodium-glucose co-transporter-2 (SGLT2) inhibitors are novel drugs which have recently seen rapid uptake in the treatment of type 2 diabetes and obesity. The paucity of data regarding their safety during pregnancy and lactation causes a dilemma for the physician. The aim of the present study was to systematically review all available data on the offspring effects of GLP-1 agonists and SGLT2 inhibitors during pregnancy and lactation.

Methods

We systematically searched PubMed, clinicaltrials.gov, FDA and EMA product information on GLP-1 agonists and SGLT2 inhibitors in pregnancy and lactation from inception up to 19 April 2022 without language restrictions. We approached both the Netherlands Pharmacovigilance Centre Lareb on January 17th 2023 and the Teratology Information Service (TIS) of Switzerland on February 6th 2023. Eligible studies investigating the safety (including congenital anomalies, fetal growth, perinatal demise) in animals or humans, or reporting the degree of transfer of these drugs to the fetus, breast milk or breastfed neonate. Two reviewers independently assessed and selected studies for inclusion and subsequently resolved discrepancies by discussion.

Results

We included 39 records (n=9 theoretical; based on drug properties, n=7 human; n=23 animal, including 76 human offspring, and an unknown number of animal offspring as these numbers could not be retrieved from the FDA and EMA product information). In animal studies, GLP1-agonists were associated with reduced fetal weight and/or growth, delayed ossification and skeletal variants, usually associated with a reduction in maternal weight gain and decreased food consumption. Exendin-4 (GLP1-agonist) was not transported across the maternal-fetal placental interface. In human studies, exenatide (GLP1-agonist) showed a fetal-to-maternal peptide concentration ratio of ≤ 0.017 in ex vivo human placental perfusion in a single placenta. Liraglutide (GLP1-agonist) showed no significant maternal to fetal transfer at least 3.5 hours after maternal exposure in a human study with one subject. In animal studies, GLP-1 agonists were excreted in breast milk; human data on excretion were not available. In animal studies, SGLT2 inhibitors were generally safe during the first trimester but exposure during postnatal day 21 to 90 in juvenile rats, a period coinciding with the late second and third trimester of human renal development, caused dilatation of the renal pelvis and tubules. Human data consisted of a pharmaceutical database of inadvertent pregnancies during SGLT2 inhibitor use, which found an increase in miscarriages and congenital malformations. In animal studies SGLT2 inhibitors were excreted in breast milk and affected neonatal growth, but human data are not available.

Conclusion/interpretation

We found evidence for adverse offspring effects of GLP-1 agonists and SGLT2 inhibitors also in human studies. Our findings broadly support the advice to discontinue GLP-1 agonists and SGLT2 inhibitors during pregnancy and lactation, and also support the ongoing registration of pregnancy outcomes in pharmacological databases since the amount of available data is scarce and mostly limited to animal studies.

Registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=219877.

Effects of repeated developmental GLP-1R agonist exposure on young adult behavior and hippocampal structure in mice

Glucagon-like peptide-1 receptor (GLP-1R) agonists are common type 2 diabetes medications that have been repurposed for adult chronic weight management. Clinical trials suggest this class may also be beneficial for obesity in pediatric populations. Since several GLP-1R agonists cross the blood-brain barrier, it is important to understand how postnatal developmental exposure to GLP-1R agonists might affect brain structure and function later in life. Toward that end, we systemically treated male and female C57BL/6 mice with the GLP-1R agonist exendin-4 (0.5 mg/kg, twice daily) or saline from postnatal day 14 to 21, then allowed uninterrupted development to young adulthood. Beginning at 7 weeks of age, we performed open field and marble burying tests to assess motor behavior and the spontaneous location recognition (SLR) task to assess hippocampal-dependent pattern separation and memory. Mice were sacrificed, and we counted ventral hippocampal mossy cells, as we have recently shown that most murine hippocampal neuronal GLP-1R is expressed in this cell population. We found that GLP-1R agonist treatment did not alter P14-P21 weight gain, but modestly reduced young adult open field distance traveled and marble burying. Despite these motor changes, there was no effect on SLR memory performance or time spent investigating objects. Finally, we did not detect any changes in ventral mossy cell number using two different markers. These data suggest developmental exposure to GLP-1R agonists might have specific rather than global effects on behavior later in life and that extensive additional study is necessary to clarify how drug timing and dose affect distinct constellations of behavior in young adulthood.

Effects of repeated developmental GLP-1R agonist exposure on adult behavior and hippocampal structure in mice

Glucagon-like peptide-1 receptor (GLP-1R) agonists are common type 2 diabetes medications that have been repurposed for adult chronic weight management. Clinical trials suggest this class may also be beneficial for obesity in pediatric populations. Since several GLP-1R agonists cross the blood-brain barrier, it is important to understand how postnatal developmental exposure to GLP-1R agonists might affect brain structure and function in adulthood. Toward that end, we systemically treated male and female C57BL/6 mice with the GLP-1R agonist exendin-4 (0.5 mg/kg, twice daily) or saline from postnatal day 14 to 21, then allowed uninterrupted development to adulthood. Beginning at 7 weeks of age, we performed open field and marble burying tests to assess motor behavior and the spontaneous location recognition (SLR) task to assess hippocampal-dependent pattern separation and memory. Mice were sacrificed, and we counted ventral hippocampal mossy cells, as we have recently shown that most murine hippocampal neuronal GLP-1R is expressed in this cell population. We found that GLP-1R agonist treatment did not alter P14-P21 weight gain, but modestly reduced adult open field distance traveled and marble burying. Despite these motor changes, there was no effect on SLR memory performance or time spent investigating objects. Finally, we did not detect any changes in ventral mossy cell number using two different markers. These data suggest developmental exposure to GLP-1R agonists might have specific rather than global effects on behavior later in life and that extensive additional study is necessary to clarify how drug timing and dose affect distinct constellations of behavior in adulthood.

Behavioral and Neuroanatomical Consequences of Cell-Type Specific Loss of Dopamine D2 Receptors in the Mouse Cerebral Cortex

Developmental dysregulation of dopamine D2 receptors (D2Rs) alters neuronal migration, differentiation, and behavior and contributes to the psychopathology of neurological and psychiatric disorders. The current study is aimed at identifying how cell-specific loss of D2Rs in the cerebral cortex may impact neurobehavioral and cellular development, in order to better understand the roles of this receptor in cortical circuit formation and brain disorders. We deleted D2R from developing cortical GABAergic interneurons (Nkx2.1-Cre) or from developing telencephalic glutamatergic neurons (Emx1-Cre). Conditional knockouts (cKO) from both lines, Drd2^fl/fl, Nkx2.1-Cre⁺ (referred to as GABA-D2R-cKO mice) or Drd2^fl/fl, Emx1-Cre⁺ (referred to as Glu-D2R-cKO mice), exhibited no differences in simple tests of anxiety-related or depression-related behaviors, or spatial or nonspatial working memory. Both GABA-D2R-cKO and Glu-D2R-cKO mice also had normal basal locomotor activity, but GABA-D2R-cKO mice expressed blunted locomotor responses to the psychotomimetic drug MK-801. GABA-D2R-cKO mice exhibited improved motor coordination on a rotarod whereas Glu-D2R-cKO mice were normal. GABA-D2R-cKO mice also exhibited spatial learning deficits without changes in reversal learning on a Barnes maze. At the cellular level, we observed an increase in PV+ cells in the frontal cortex of GABA-D2R-cKO mice and no noticeable changes in Glu-D2R-cKO mice. These data point toward unique and distinct roles for D2Rs within excitatory and inhibitory neurons in the regulation of behavior and interneuron development, and suggest that location-biased D2R pharmacology may be clinically advantageous to achieve higher efficacy and help avoid unwanted effects.