Management of sulfonylurea-treated monogenic diabetes in pregnancy: implications of placental glibenclamide transfer

Management of pregnancy in women with monogenic diabetes due to mutations in GCK, HNF1A and HNF4A genes

Women with maturity-onset diabetes of the young (MODY) need tailored antenatal care and monitoring of their offspring. Each MODY subtype has different implications for glycaemic targets, treatment choices and neonatal management. Hyperglycaemia of MODY is often first diagnosed in adolescence or early adulthood and therefore is clinically relevant to pregnant women. MODY remains an under-recognised and undiagnosed condition. Pregnancy represents an opportune time to make a genetic diagnosis of MODY and provide precision treatment. This review describes the nuance of antenatal care in women with MODY and the implications for pregnancies affected by a positive paternal genotype. Mutations in hepatic nuclear factor 1-alpha (HNF1A) and 4-alpha (HNF4A) genes are associated with progressive β-cell dysfunction resulting in early onset diabetes. Patients are largely managed with sulphonylureas outside of pregnancy. Macrosomia and persistent neonatal hypoglycaemia are reported in 54% and 15% of HNF4A genotype positive offspring respectively with a median increase in birthweight of 790 g. Close observation of foetal growth in utero allows optimal timing of delivery to minimise peri- and postpartum materno-foetal complications. Glucokinase (GCK)-MODY causes mild fasting hyperglycaemia which does not require treatment outside of pregnancy. Birthweight of offspring of maternal carriers is dependent on foetal genotype; heterozygous mutation carriers are usually normal weight while genotype negative offspring are large for gestational age (600 g heavier). Affected offspring of paternal carriers may be small for gestational age (500 g lighter). Serial growth scans with measurement of the abdominal circumference indirectly differentiate foetal genotype. Measurement of cell free foetal DNA in maternal blood from the late first trimester is superior to traditionally used ultrasound to distinguish foetal genotype. Cost and accessibility may limit its use.

Genetic and Epigenetic Factors in Gestational Diabetes Mellitus Pathology

Gestational diabetes (GDM) is the carbohydrate intolerance occurring during pregnancy. The risk factors of GDM include obesity, advanced maternal age, polycystic ovary syndrome, multigravidity, a sedentary lifestyle, and pre-existing hypertension. Additionally, complex genetic and epigenetic processes are also believed to play a crucial role in the development of GDM. In this narrative review, we discuss the role of genetic and epigenetic factors in gestational diabetes mellitus pathogenesis.

Maturity-onset Diabetes of the Young (MODY) in Pregnancy: A Review

Hyperglycaemia in pregnancy is one of the most common complications of pregnancy and is generally diagnosed as gestational diabetes mellitus (GDM). Nevertheless, clinical symptoms of hyperglycaemia in pregnancy in some cases do not match the clinical manifestations of GDM. It is suspected that 1-2 % of women diagnosed with GDM are misdiagnosed maturity-onset diabetes of the young (MODY). MODY often has a subclinical course; thus, it is challenging for clinicians to aptly diagnose monogenic diabetes in pregnancy. Proper diagnosis is crucial for the effective treatment of hyperglycaemia in pregnancy. Many studies revealed that misdiagnosis of MODY increases the rate of complications for both mother and fetus. This literature review reports the current knowledge regarding diagnosis, treatment, and complications of the most common types of MODY in pregnancy.

Improvements in Awareness and Testing Have Led to a Threefold Increase Over 10 Years in the Identification of Monogenic Diabetes in the U.K

OBJECTIVE

Maturity-onset diabetes of the young (MODY) is a rare monogenic form of diabetes. In 2009, >80% of U.K. cases were estimated to be misdiagnosed. Since then, there have been a number of initiatives to improve the awareness and detection of MODY, including education initiatives (Genetic Diabetes Nurse [GDN] project), the MODY probability calculator, and targeted next-generation sequencing (tNGS). We examined how the estimated prevalence of MODY and other forms of monogenic diabetes diagnosed outside the neonatal period has changed over time and how the initiatives have impacted case finding.

RESEARCH DESIGN AND METHODS

U.K. referrals for genetic testing for monogenic diabetes diagnosed >1 year of age from 1 January 1996 to 31 December 2019 were examined. Positive test rates were compared for referrals reporting GDN involvement/MODY calculator use with those that did not.

RESULTS

A diagnosis of monogenic diabetes was confirmed in 3,860 individuals, more than threefold higher than 2009 (1 January 1996 to 28 February 2009, n = 1,177). Median age at diagnosis in probands was 21 years. GDN involvement was reported in 21% of referrals; these referrals had a higher positive test rate than those without GDN involvement (32% vs. 23%, P < 0.001). MODY calculator usage was indicated in 74% of eligible referrals since 2014; these referrals had a higher positive test rate than those not using the calculator (33% vs. 25%, P = 0.001). Four hundred ten (10.6%) cases were identified through tNGS. Monogenic diabetes prevalence was estimated to be 248 cases/million (double that estimated in 2009 because of increased case finding).

CONCLUSIONS

Since 2009, referral rates and case diagnosis have increased threefold. This is likely to be the consequence of tNGS, GDN education, and use of the MODY calculator.

Role of Actionable Genes in Pursuing a True Approach of Precision Medicine in Monogenic Diabetes

Monogenic diabetes is a genetic disorder caused by one or more variations in a single gene. It encompasses a broad spectrum of heterogeneous conditions, including neonatal diabetes, maturity onset diabetes of the young (MODY) and syndromic diabetes, affecting 1-5% of patients with diabetes. Some of these variants are harbored by genes whose altered function can be tackled by specific actions ("actionable genes"). In suspected patients, molecular diagnosis allows the implementation of effective approaches of precision medicine so as to allow individual interventions aimed to prevent, mitigate or delay clinical outcomes. This review will almost exclusively concentrate on the clinical strategy that can be specifically pursued in carriers of mutations in "actionable genes", including ABCC8, KCNJ11, GCK, HNF1A, HNF4A, HNF1B, PPARG, GATA4 and GATA6. For each of them we will provide a short background on what is known about gene function and dysfunction. Then, we will discuss how the identification of their mutations in individuals with this form of diabetes, can be used in daily clinical practice to implement specific monitoring and treatments. We hope this article will help clinical diabetologists carefully consider who of their patients deserves timely genetic testing for monogenic diabetes.

Inhibition of NLRP3 inflammasome by glibenclamide attenuated dopaminergic neurodegeneration and motor deficits in paraquat and maneb-induced mouse Parkinson's disease model

Pesticides exposure can lead to damage of dopaminergic neurons, which are associated with increased risk of Parkinson's disease (PD). However, the etiology of PD remains poorly understood and no therapeutic strategy is available. Previous studies suggested the involvement of NLRP3 inflammasome in the onset of PD. This study was designed to investigate whether glibenclamide, an inhibitor of NLRP3 inflammasome, could offer a reliable protective strategy for PD in a mouse PD model induced by paraquat and maneb. We found that glibenclamide exerted potent neuroprotection against paraquat and maneb-induced upregulation of α-synuclein, dopaminergic neurodegeneration and motor impairment in brain of mice. Mechanistically, glibenclamide treatment blocked NLRP3 inflammasome activation evidenced by reduced expressions of NLRP3, activated caspase-1 and mature interleukin-1β in glibenclamide co-treated mice compared with those in paraquat and maneb group mice. Furthermore, glibenclamide treatment mitigated paraquat and maneb-induced microglial M1 proinflammatory response and nuclear factor-κB activation in mice. Finally, the increased superoxide production, lipid peroxidation, protein levels of NADPH oxidase 2 (NOX2) and inducible nitric oxide synthase (iNOS) induced by paraquat and maneb were all attenuated by glibenclamide. Overall, our findings demonstrated that glibenclamide protected dopaminergic neurons in a mouse PD model induced by combined exposures of paraquat and maneb through suppression of NLRP3 inflammasome activation, microglial M1 polarization and oxidative stress.

Monogenic Diabetes: From Genetic Insights to Population-Based Precision in Care. Reflections From a Diabetes Care Editors' Expert Forum

Individualization of therapy based on a person's specific type of diabetes is one key element of a "precision medicine" approach to diabetes care. However, applying such an approach remains difficult because of barriers such as disease heterogeneity, difficulties in accurately diagnosing different types of diabetes, multiple genetic influences, incomplete understanding of pathophysiology, limitations of current therapies, and environmental, social, and psychological factors. Monogenic diabetes, for which single gene mutations are causal, is the category most suited to a precision approach. The pathophysiological mechanisms of monogenic diabetes are understood better than those of any other form of diabetes. Thus, this category offers the advantage of accurate diagnosis of nonoverlapping etiological subgroups for which specific interventions can be applied. Although representing a small proportion of all diabetes cases, monogenic forms present an opportunity to demonstrate the feasibility of precision medicine strategies. In June 2019, the editors of Diabetes Care convened a panel of experts to discuss this opportunity. This article summarizes the major themes that arose at that forum. It presents an overview of the common causes of monogenic diabetes, describes some challenges in identifying and treating these disorders, and reports experience with various approaches to screening, diagnosis, and management. This article complements a larger American Diabetes Association effort supporting implementation of precision medicine for monogenic diabetes, which could serve as a platform for a broader initiative to apply more precise tactics to treating the more common forms of diabetes.

ADIPS 2020 guideline for pre-existing diabetes and pregnancy

This is the full version of the Australasian Diabetes in Pregnancy Society (ADIPS) 2020 guideline for pre-existing diabetes and pregnancy. The guideline encompasses the management of women with pre-existing type 1 diabetes and type 2 diabetes in relation to pregnancy, including preconception, antepartum, intrapartum and postpartum care. The management of women with monogenic diabetes or cystic fibrosis-related diabetes in relation to pregnancy is also discussed.

Treatment Options for MODY Patients: A Systematic Review of Literature

Maturity-onset diabetes of the young (MODY) is an unusual form of diabetes with specific features that distinguish it from type 1 and type 2 diabetes. There are 14 known subtypes of MODY, and mutations in three genes (HNF1A, HNF4A, GCK) account for about 95% of all MODY cases. Diagnosis usually occurs before the age of 25 years, although less frequent forms may occur more often-but not necessarily-later in life. The molecular diagnosis may tailor the choice of the most appropriate treatment, with the aim to optimize blood glucose control, reduce the risk of hypoglycemic events and long-term complications, and enable proper genetic counseling. Treatment is usually unnecessary for patients with mutations in the GCK gene, while oral hypoglycemic agents (generally sulphonylureas) are recommended for patients with mutations in the HNF4A and HNF1A genes. More recent data show that other glucose-lowering agents can be effective in the latter patients, and additional and alternative therapies have been proposed. Proper management guidelines during pregnancy have been developed for carriers of GCK gene mutations, but such guidelines are still a subject of debate in other cases, although some recommendations are available. The other subtypes of MODY are even more rare, and very little data are available in the literature. In this review we summarize the most pertinent findings and recommendations on the treatment of patients with the different subtypes of MODY. Our aim is to provide the reader with an easy-to-read update that can be used to drive the clinician's therapeutical approach to these patients after the molecular diagnosis.

Identification of MODY among patients screened for gestational diabetes: a clinician's guide

PURPOSE

Screening of gestational diabetes/GDM (although different in different countries) represents a standard procedure allowing to identify women with pregnancy-associated diabetes. Some of the women with GDM (up to 5%) may, however, suffer from previously undiagnosed MODY (Maturity-Onset Diabetes of the Young). Currently, no international or local guidelines focused on the identification of MODY among GDM exist. Thus, the aim of this manuscript is to propose a clear guide for clinicians on how to detect MODY among pregnant women with gestational diabetes.

METHODS

Based on the available literature about diagnosis (in general population) of MODY and management of MODY (both, in general population and in pregnant women), we propose a clear clinical guide on how to diagnose and manage MODY in pregnancy.

RESULTS

The manuscript suggests a feasible clinical approach how to recognize MODY among patients with GDM and how to manage pregnancy of women with three most common MODY subtypes.

CONCLUSION

A correct classification of diabetes is, nonetheless, essential, particularly in case of MODY, as the management of pregnant women with MODY is different and the correct diagnosis of MODY enables individualized treatment with regard to optimal pregnancy outcomes.

Update of variants identified in the pancreatic β-cell KATP channel genes KCNJ11 and ABCC8 in individuals with congenital hyperinsulinism and diabetes

The most common genetic cause of neonatal diabetes and hyperinsulinism is pathogenic variants in ABCC8 and KCNJ11. These genes encode the subunits of the β-cell ATP-sensitive potassium channel, a key component of the glucose-stimulated insulin secretion pathway. Mutations in the two genes cause dysregulated insulin secretion; inactivating mutations cause an oversecretion of insulin, leading to congenital hyperinsulinism, whereas activating mutations cause the opposing phenotype, diabetes. This review focuses on variants identified in ABCC8 and KCNJ11, the phenotypic spectrum and the treatment implications for individuals with pathogenic variants.

Screening for monogenic diabetes in primary care

AIMS

Updates on the latest diagnostic methods and features of MODY (Maturity Onset Diabetes of the Young) and promotion of education and awareness on the subject are discussed.

METHOD

Previous recommendations were identified using PubMed and using combinations of terms including "MODY" "monogenic diabetes" "mature onset diabetes" "MODY case review". The diabetesgenes.org website and the US Monogenic Diabetes Registry (University of Colorado) were directly referenced. The remaining referenced papers were taken from peer-reviewed journals. The initial literature search occurred in January 2017 and the final search occurred in September 2018.

RESULTS

A diagnosis of MODY has implications for treatment, quality of life, management in pregnancy and research. The threshold for referral and testing varies among different ethnic groups, and depends on body mass index, family history of diabetes and associated syndromes. Novel causative genetic variations are still being discovered however testing is currently limited by low referral rates. Educational material is currently being promoted in the UK in an effort to raise awareness.

CONCLUSIONS

The benefits and implications of life altering treatment such as termination of insulin administration are significant but little can be done without appropriate identification and referral.

Management and Outcomes of Maturity-Onset Diabetes of the Young in Pregnancy

Maturity-onset diabetes of the young (MODY) is a group of monogenic disorders that accounts for 1% to 5% of diabetes. The most common mutations are those in the hepatocyte nuclear factor-1-alpha (HNF-1-alpha) and in the glucokinase (GCK) genes. Although management of MODY is well established, no guidelines currently exist for management during pregnancy. Both maternal glycemic control and fetal mutation status are factors that may influence outcomes during pregnancy. The primary aim of this project was to describe cases of MODY during pregnancy to highlight the clinical implications of management of this disorder during pregnancy. The Ottawa Hospital is the primary referral centre for high-risk obstetrical patients, including those with diabetes in pregnancy, in Ottawa, Canada. Referrals between 2008 and 2018 were reviewed and a case series of three women and five pregnancies is described. Together with the illustrative cases, a literature review of MODY in pregnancy is used to highlight clinical considerations unique to MODY in pregnancy. We describe 5 pregnancies with MODY-2 (GCK mutation) and MODY 3 (HNF-1-alpha mutation). Important issues identified included monitoring of fetal growth and individualization of maternal glycemic control, particularly in cases where fetal mutation status is unknown. Management of MODY in pregnancy is challenging and there is little evidence to guide recommendations. Fetal growth can be used to guide management of maternal glycemic targets when fetal mutation status is unknown.

Monogenic Forms of Diabetes Mellitus

In addition to the common types of diabetes mellitus, two major monogenic diabetes forms exist. Maturity-onset diabetes of the young (MODY) represents a heterogenous group of monogenic, autosomal dominant diseases. MODY accounts for 1-2% of all diabetes cases, and it is not just underdiagnosed but often misdiagnosed to type 1 or type 2 diabetes. More than a dozen MODY genes have been identified to date, and their molecular classification is of great importance in the correct treatment decision and in the judgment of the prognosis. The most prevalent subtypes are HNF1A, GCK, and HNF4A. Genetic testing for MODY has changed recently due to the technological advancements, as contrary to the sequential testing performed in the past, nowadays all MODY genes can be tested simultaneously by next-generation sequencing. The other major group of monogenic diabetes is neonatal diabetes mellitus which can be transient or permanent, and often the diabetes is a part of a syndrome. It is a severe monogenic disease appearing in the first 6 months of life. The hyperglycemia usually requires insulin. There are two forms, permanent neonatal diabetes mellitus (PNDM) and transient neonatal diabetes mellitus (TNDM). In TNDM, the diabetes usually reverts within several months but might relapse later in life. The incidence of NDM is 1:100,000-1:400,000 live births, and PNDM accounts for half of the cases. Most commonly, neonatal diabetes is caused by mutations in KCNJ11 and ABCC8 genes encoding the ATP-dependent potassium channel of the β cell. Neonatal diabetes has experienced a quick and successful transition into the clinical practice since the discovery of the molecular background. In case of both genetic diabetes groups, recent guidelines recommend genetic testing.

Monogenic diabetes: the impact of making the right diagnosis

PURPOSE OF REVIEW

Monogenic forms of diabetes have received increased attention and genetic testing is more widely available; however, many patients are still misdiagnosed as having type 1 (T1D) or type 2 diabetes. This review will address updates to monogenic diabetes prevalence, identification, treatment, and genetic testing.

RECENT FINDINGS

The creation of a T1D genetic risk score and the use of noninvasive urinary C-peptide creatinine ratios have provided new tools to aid in the discrimination of possible monogenic diabetes from likely T1D. Early, high-dose sulfonylurea treatment in infants with a KCNJ11 or ABCC8 mutation continues to be well tolerated and effective. As the field moves towards more comprehensive genetic testing methods, there is an increased opportunity to identify novel genetic causes. Genetic testing results continue to allow for personalized treatment but should provide patient information at an appropriate health literacy level.

SUMMARY

Although there have been clinical and genetic advances in monogenic diabetes, patients are still misdiagnosed. Improved insurance coverage of genetic testing is needed. The majority of data on monogenic diabetes has been collected from Caucasian populations, therefore, research studies should endeavor to include broader ethnic and racial diversity to provide comprehensive information for all populations.

Clinical Management of Women with Monogenic Diabetes During Pregnancy

PURPOSE OF REVIEW

Monogenic diabetes accounts for 1-2% of all diabetes cases, but is frequently misdiagnosed as type 1, type 2, or gestational diabetes. Accurate genetic diagnosis directs management, such as no pharmacologic treatment for GCK-MODY, low-dose sulfonylureas for HNF1A-MODY and HNF4A-MODY, and high-dose sulfonylureas for K_ATP channel-related diabetes. While diabetes treatment is defined for the most common causes of monogenic diabetes, pregnancy poses a challenge to management. Here, we discuss the key issues in pregnancy affected by monogenic diabetes.

RECENT FINDINGS

General recommendations for pregnancy affected by GCK-MODY determine need for maternal insulin treatment based on fetal mutation status. However, a recent study suggests macrosomia and miscarriage rates may be increased with this strategy. Recent demonstration of transplacental transfer of sulfonylureas also raises questions as to when insulin should be initiated in sulfonylurea-responsive forms of monogenic diabetes. Pregnancy represents a challenge in management of monogenic diabetes, where factors of maternal glycemic control, fetal mutation status, and transplacental transfer of medication must all be taken into consideration. Guidelines for pregnancy affected by monogenic diabetes will benefit from large, prospective studies to better define the need for and timing of initiation of insulin treatment.

Use of oral antidiabetic drugs in the treatment of maturity-onset diabetes of the young: A mini review

MODY (maturity-onset diabetes of the young) is a genetically linked group of clinically heterogeneous subtypes of diabetes. Roughly 5% of people with diabetes mellitus diagnosed prior to age 45 have MODY diabetes. Most of them have been erroneously diagnosed as patients with either type 1 or type 2 diabetes and, as a result, have been improperly treated. Genetic identification of MODY diabetes and its subtypes allows proper treatment and enables clinicians to switch many patients to oral antidiabetic agents, mainly sulphonylureas. However, some new classes of oral antidiabetic drugs have also been tested and found to be effective in MODY patients. We have searched for research articles and case reports written in full-text English or with an English abstract, using the following keywords: MODY and oral antidiabetic* in the databases Cochrane Library, PubMed, and Science Direct. Therapeutic options using currently standardized oral antidiabetic drugs (mainly sulphonylureas), as well as more experimental treatment with other classes of oral antidiabetic drugs in different types of MODY, are discussed, with special focus on the therapy of the most common MODY subtypes, including specific conditions such as pregnancy. This review article summarizes the currently available information about oral antidiabetic treatment of patients with MODY diabetes.

Management of sulfonylurea-treated monogenic diabetes in pregnancy: implications of placental glibenclamide transfer

The optimum treatment for HNF1A/HNF4A maturity-onset diabetes of the young and ATP-sensitive potassium (K_ATP ) channel neonatal diabetes, outside pregnancy, is sulfonylureas, but there is little evidence regarding the most appropriate treatment during pregnancy. Glibenclamide has been widely used in the treatment of gestational diabetes, but recent data have established that glibenclamide crosses the placenta and increases risk of macrosomia and neonatal hypoglycaemia. This raises questions about its use in pregnancy. We review the available evidence and make recommendations for the management of monogenic diabetes in pregnancy. Due to the risk of stimulating increased insulin secretion in utero, we recommend that in women with HNF1A/ HNF4A maturity-onset diabetes of the young, those with good glycaemic control who are on a sulfonylurea per conception either transfer to insulin before conception (at the risk of a short-term deterioration of glycaemic control) or continue with sulfonylurea (glibenclamide) treatment in the first trimester and transfer to insulin in the second trimester. Early delivery is needed if the fetus inherits an HNF4A mutation from either parent because increased insulin secretion results in ~800-g weight gain in utero, and prolonged severe neonatal hypoglycaemia can occur post-delivery. If the fetus inherits a K_ATP neonatal diabetes mutation from their mother they have greatly reduced insulin secretion in utero that reduces fetal growth by ~900 g. Treating the mother with glibenclamide in the third trimester treats the affected fetus in utero, normalising fetal growth, but is not desirable, especially in the high doses used in this condition, if the fetus is unaffected. Prospective studies of pregnancy in monogenic diabetes are needed.