Factors associated with maternal hyperglycaemia and neonatal hypoglycaemia after antenatal betamethasone administration in women with diabetes in pregnancy

AIMS

Bespoke glycaemic control strategies following antenatal corticosteroids for women with diabetes in pregnancy (DIP) may mitigate hyperglycaemia. This study aims to identify predictive factors for the glycaemic response to betamethasone in a large cohort of women with DIP.

METHODS

Evaluation of a prospective cohort study of 347 consecutive DIP pregnancies receiving two doses of 11.4 mg betamethasone 24 h apart between 2017 and 2021 and treated with the Pregnancy-IVI intravenous insulin protocol. Regression modelling identified factors associated with maternal glycaemic time-in-range (TIR) and maternal insulin requirements following betamethasone. Factors associated with neonatal hypoglycaemia (glucose <2.6 mmol/L) in infants born within 48 h of betamethasone administration (n = 144) were investigated.

RESULTS

The mean maternal age was 31.9 ± 5.8 years, with gestational age at betamethasone of 33.5 ± 3.4 weeks. Gestational diabetes was present in 81% (12% type 1; 7% type 2). Pre-admission subcutaneous insulin was prescribed for 63%. On-infusion maternal glucose TIR (4.0-7.8 mmol/L) was 83% [IQR 77%-90%] and mean on-IVI glucose was 6.6 ± 0.5 mmol/L. Maternal hypoglycaemia (<3.8 mmol/L) was uncommon (0.47 h/100 on-IVI woman hours). Maternal glucose TIR was negatively associated with indicators of insulin resistance (type 2 diabetes, polycystic ovary syndrome), late-pregnancy complications (pre-eclampsia, chorioamnionitis) and the 1-h OGTT result. Intravenous insulin requirements were associated with type of diabetes, pre-eclampsia and intrauterine infection, the 1-h OGTT result and the timing of betamethasone administration. Neonatal hypoglycaemia was associated with pre-existing diabetes but not with measures of glycaemic control.

CONCLUSION

An intravenous infusion protocol effectively controls maternal glucose after betamethasone. A risk-factor-based approach may allow individualisation of therapy.

Sequencing candidate genes in African American and Hispanic/ Latino probands with early-onset Atrial Fibrillation

Introduction

Mutations in cardiac ion channels, structural proteins and signaling molecules have been identified in European whites with early-onset AF (EOAF). However, it remains unclear if genetic variation also contributes to the etiology of EOAF in ethnic minorities.

Purpose

To determine the prevalence of disease causing variants in candidate AF genes in African American and Hispanic/Latino probands with EOAF.

Method

In this family-based study, probands of African and Hispanic descent with EOAF (defined as AF ≤65 years) were prospectively enrolled in a clinical-DNA biorepository and underwent targeted sequencing for 60 AF candidate genes. Variants were filtered at 20X read depth and clinically evaluated with American College of Medical Genetics and Genomics and Association for Molecular Pathology (ACMG/AMP) as well as the Association for Clinical Genomic Science (ACGS) criteria for disease-causing mutations.

Results

Among 227 EOAF probands with mean (SD) age of AF 51.0 (9.9) years, 132 (58.0%) were men and 148 (65.0%) African American and 79 (35.0%) Hispanic/Latino. Sequencing 60 candidate AF genes revealed 90 variants that met filtering criteria and underwent clinical evaluation. We identified 16 (7.0%) EOAF probands with a likely pathogenic or pathogenic variant with the majority being loss of function (62.5%) and located in the TTN gene (50.0%). We confirmed a family history of AF in 24 probands (10.6%) and 6 families with &gt;1 affected member a variant of unknown significance (VUS) in genes encoding for a sodium channel (SCN10A), potassium channel (KCNE5), sarcomeric proteins (MYH6, TTN) and atrial natriuretic peptide (NPPA) co-segregated with AF.

Conclusion

Gene sequencing in African American and Hispanic/Latinos probands with EOAF identified a small percentage of disease causing variants in patients with EOAF. Our findings not only represent important progress toward molecular phenotyping of EOAF, but also provides insight into the underlying pathophysiology toward targeted mechanism-based therapies for AF in ethnic minorities.

Funding Acknowledgement

Type of funding source: Private grant(s) and/or Sponsorship. Main funding source(s): American Heart Association