Fetal growth is increased by maternal type 1 diabetes and HLA DR4-related gene interactions

15. Management of Diabetes in Pregnancy: Standards of Care in Diabetes-2024

The American Diabetes Association (ADA) "Standards of Care in Diabetes" includes the ADA's current clinical practice recommendations and is intended to provide the components of diabetes care, general treatment goals and guidelines, and tools to evaluate quality of care. Members of the ADA Professional Practice Committee, an interprofessional expert committee, are responsible for updating the Standards of Care annually, or more frequently as warranted. For a detailed description of ADA standards, statements, and reports, as well as the evidence-grading system for ADA's clinical practice recommendations and a full list of Professional Practice Committee members, please refer to Introduction and Methodology. Readers who wish to comment on the Standards of Care are invited to do so at professional.diabetes.org/SOC.

The countdown to type 1 diabetes: when, how and why does the clock start?

'The clock to type 1 diabetes has started when islet antibodies are first detected', commented George Eisenbarth with regard to the pathogenesis of type 1 diabetes. This review focuses on 'starting the clock', i.e. the initiation of pre-symptomatic islet autoimmunity/the first appearance of islet autoantibodies. In particular, this review addresses why susceptibility to developing islet autoimmunity is greatest in the first 2 years of life and why beta cells are a frequent target of the immune system during this fertile period. A concept for the development of beta cell autoimmunity in childhood is discussed and three factors are highlighted that contribute to this early predisposition: (1) high beta cell activity and potential vulnerability to stress; (2) high rates of and first exposures to infection; and (3) a heightened immune response, with a propensity for T helper type 1 (Th1) immunity. Arguments are presented that beta cell injury, accompanied by activation of an inflammatory immune response, precedes the initiation of autoimmunity. Finally, the implications for strategies aimed at primary prevention for a world without type 1 diabetes are discussed.

15. Management of Diabetes in Pregnancy: Standards of Care in Diabetes-2023

The American Diabetes Association (ADA) "Standards of Care in Diabetes" includes the ADA's current clinical practice recommendations and is intended to provide the components of diabetes care, general treatment goals and guidelines, and tools to evaluate quality of care. Members of the ADA Professional Practice Committee, a multidisciplinary expert committee, are responsible for updating the Standards of Care annually, or more frequently as warranted. For a detailed description of ADA standards, statements, and reports, as well as the evidence-grading system for ADA's clinical practice recommendations and a full list of Professional Practice Committee members, please refer to Introduction and Methodology. Readers who wish to comment on the Standards of Care are invited to do so at professional.diabetes.org/SOC.

15. Management of Diabetes in Pregnancy: Standards of Medical Care in Diabetes-2022

The American Diabetes Association (ADA) "Standards of Medical Care in Diabetes" includes the ADA's current clinical practice recommendations and is intended to provide the components of diabetes care, general treatment goals and guidelines, and tools to evaluate quality of care. Members of the ADA Professional Practice Committee, a multidisciplinary expert committee (https://doi.org/10.2337/dc22-SPPC), are responsible for updating the Standards of Care annually, or more frequently as warranted. For a detailed description of ADA standards, statements, and reports, as well as the evidence-grading system for ADA's clinical practice recommendations, please refer to the Standards of Care Introduction (https://doi.org/10.2337/dc22-SINT). Readers who wish to comment on the Standards of Care are invited to do so at professional.diabetes.org/SOC.

14. Management of Diabetes in Pregnancy: Standards of Medical Care in Diabetes-2021

The American Diabetes Association (ADA) "Standards of Medical Care in Diabetes" includes the ADA's current clinical practice recommendations and is intended to provide the components of diabetes care, general treatment goals and guidelines, and tools to evaluate quality of care. Members of the ADA Professional Practice Committee, a multidisciplinary expert committee (https://doi.org/10.2337/dc21-SPPC), are responsible for updating the Standards of Care annually, or more frequently as warranted. For a detailed description of ADA standards, statements, and reports, as well as the evidence-grading system for ADA's clinical practice recommendations, please refer to the Standards of Care Introduction (https://doi.org/10.2337/dc21-SINT). Readers who wish to comment on the Standards of Care are invited to do so at professional.diabetes.org/SOC.

A Pragmatic Approach to the Treatment of Women With Type 2 Diabetes in Pregnancy

Type 2 diabetes mellitus (DM) is a growing problem among reproductive-aged women. Contemporary trends in obesity and delayed child-bearing are expected to result in an increasing number of pregnancies affected by type 2 DM. Women with known type 2 DM can greatly benefit from preconception care as improved periconception glycemic control and weight loss can decrease the neonatal and maternal risks associated with type 2 DM and pregnancy. Antenatal mainstays of management include frequent blood glucose monitoring, insulin therapy, optimization of coexisting medical conditions, and fetal surveillance. Careful attention to postpartum glucose control, infant feeding choices, and contraceptive counseling are important aspects of immediate postpartum care.

Pre-Gestational Diabetes and Pregnancy Outcomes

INTRODUCTION

Pre-gestational, type 1 and type 2 diabetes are associated with adverse neonatal outcomes and increased rates of emergency caesarean sections.

METHODS

We studied pregnancy outcomes associated with pre-gestational diabetes in 174 women who attended the National Maternity Hospital in Dublin, Ireland, between 2015 and 2017.

RESULTS

Fifty women (28.6%) had type 2 diabetes mellitus, and 124 women (71.4%) had type 1 diabetes mellitus. Women with type 2 diabetes mellitus were older (36 vs. 34 years, p 0.02) and had a higher BMI (32.6 vs. 26.2 kg/m², p 0.00). Duration of diabetes mellitus in type 1 and type 2 was 15.7 and 5.7 years, respectively, and mean HbA1c in type 2 diabetes mellitus at booking was 44.5 mmol/mol (6.2%) and in type 1 diabetes mellitus was 56.3 mmol/mol (7.3%). Forty women (32%) with type 1 diabetes mellitus used continuous subcutaneous insulin infusion. In our cohort, 45.4% had a caesarean delivery. Offspring of patients with multiple dose injections were lighter (3.58 kg) than infants of continuous subcutaneous insulin infusion-treated patients (3.75 kg). More emergency caesarean sections were observed in the continuous subcutaneous insulin infusion group than in the group treated with multiple dose injections (37.5% vs. 28.5%), while the elective caesarean section rate was higher in the multiple dose injection group (17.8% vs. 12.5%). Women treated with continuous subcutaneous insulin infusion had a higher rate of miscarriage (25% vs. 19%) with more congenital malformations (10% vs. 2.3%).

CONCLUSIONS

Women in our study with pre-gestational diabetes were overweight, were older and had long-standing diabetes mellitus. Our patients with type 2 diabetes had a higher BMI, were older, had a shorter duration of diabetes mellitus and had better diabetes control compared to women with type 1 diabetes. Women treated with continuous subcutaneous insulin infusion had a higher rate of miscarriage with more congenital malformations. The initial inadequate diabetes control was significantly improved during pregnancy.

14. Management of Diabetes in Pregnancy: Standards of Medical Care in Diabetes-2020

The American Diabetes Association (ADA) "Standards of Medical Care in Diabetes" includes the ADA's current clinical practice recommendations and is intended to provide the components of diabetes care, general treatment goals and guidelines, and tools to evaluate quality of care. Members of the ADA Professional Practice Committee, a multidisciplinary expert committee (https://doi.org/10.2337/dc20-SPPC), are responsible for updating the Standards of Care annually, or more frequently as warranted. For a detailed description of ADA standards, statements, and reports, as well as the evidence-grading system for ADA's clinical practice recommendations, please refer to the Standards of Care Introduction (https://doi.org/10.2337/dc20-SINT). Readers who wish to comment on the Standards of Care are invited to do so at professional.diabetes.org/SOC.

14. Management of Diabetes in Pregnancy: Standards of Medical Care in Diabetes-2019

The American Diabetes Association (ADA) "Standards of Medical Care in Diabetes" includes ADA's current clinical practice recommendations and is intended to provide the components of diabetes care, general treatment goals and guidelines, and tools to evaluate quality of care. Members of the ADA Professional Practice Committee, a multidisciplinary expert committee, are responsible for updating the Standards of Care annually, or more frequently as warranted. For a detailed description of ADA standards, statements, and reports, as well as the evidence-grading system for ADA's clinical practice recommendations, please refer to the Standards of Care Introduction Readers who wish to comment on the Standards of Care are invited to do so at professional.diabetes.org/SOC.

Birth weight in newborn infants with different diabetes-associated HLA genotypes in three neighbouring countries: Finland, Estonia and Russian Karelia

BACKGROUND

Human leukocyte antigen (HLA) genotypes associated with increased risk for type 1 diabetes mellitus (T1D) have been reported to be associated with increased birth weight. We set out to investigate the association between HLA haplotypes conferring risk for T1D and birth weight and search for possible differences in the strength of these associations among populations with contrasting incidence of T1D.

METHODS

As a part of the EU-funded DIABIMMUNE study, genotyping for the HLA haplotypes associated with T1D was performed in 8369 newborn infants from Estonia, Finland and Russian Karelia. Infants born before 35 gestational weeks, from mothers with diabetes, and multiple pregnancies were excluded. Relative birth weight, expressed in standard deviation scores, was estimated for each gestational week, sex and country. The standard deviation scores were calculated internally using the actual population studied. According to their HLA haplotypes, participants were divided into risk groups, and the distribution of birth weight between quartiles was analysed.

RESULTS

We did not find any direct association between various HLA risk-associated genotypes (HLA DR3-DQ2/DR4-DQ8, DR3-DQ2/X or DR4-DQ8/X) and birth weight. We observed a significant relationship between increased relative birth weight and the protective HLA-DR2-DQ6 and DR13-DQ6 haplotypes. This association was significant only when these haplotypes were found together with the DR4-DQ8 haplotype.

CONCLUSIONS

The previously reported association between HLA-risk haplotypes for T1D and an increased birth weight was not confirmed. This suggests that the mechanisms behind the association between high birth weight and risk for T1D may be not directly HLA related.

Country-specific birth weight and length in type 1 diabetes high-risk HLA genotypes in combination with prenatal characteristics

OBJECTIVE

To examine the relationship between high-risk human leukocyte antigen (HLA) genotypes for type 1 diabetes and birth size in combination with prenatal ch aracteristics in different countries.

STUDY DESIGN

Four high-risk HLA genotypes were enrolled in the Environmental determinants of Diabetes in the Young study newborn babies from the general population in Finland, Germany, Sweden and the United States. Stepwise regression analyses were used to adjust for country, parental physical characteristics and environmental factors during pregnancy.

RESULT

Regression analyses did not reveal differences in birth size between the four type 1 diabetes high-risk HLA genotypes. Compared with DQ 4/8 in each country, (1) DQ 2/2 children were heavier in the United States (P=0.028) mostly explained however, by parental weight; (2) DQ 2/8 (P=0.023) and DQ 8/8 (P=0.046) children were longer in Sweden independent of parents height and as well as (3) in the United States for DQ 2/8 (P=0.023), but again dependent on parental height.

CONCLUSION

Children born with type 1 diabetes high-risk HLA genotypes have comparable birth size. Longitudinal follow-up of these children should reveal whether birth size differences between countries contribute to the risk for islet autoimmunity and type 1 diabetes.

Association of HLA-A, -B and -DRB1 genotype with birthweight and CD34+ cell content: analysis of Korean newborns and their cord blood

Birthweight and the hematopoietic progenitor cell content in cord blood affect and reflect fetal development, and MHC has been reported to play an important role in intrauterine growth. In this study, we assessed HLA-A, -B and -DRB1 polymorphisms, birthweight and cord blood CD34(+) cell content in 1628 full-term healthy neonates to identify the HLA alleles that are associated with fetal growth in Koreans. HLA-A*31, B*47, B*51, DRB1*04 showed positive association and HLA-A*03, A*24, A*30, B*07, B*52, B*58, DRB1*03 showed negative association with birthweight and/or CD34(+) cell content; additionally, there was a greater association in homozygotes than heterozygotes revealed in the trend analysis of birthweight centile with candidate allele zygosity (A*24, P= 0.018; DRB1*04, P= 0.047). Among these alleles, HLA-A*24 and DRB1*03 showed significant negative association with birthweight and/or CD34(+) cell content after Bonferroni correction, suggesting a significant association of these alleles with fetal growth in late pregnancy (A*24, P= 0.002, P(c) = 0.026; DRB1*03, P < 0.001, P(c) < 0.001). Various populations should be analyzed to identify different or consistent factors among ethnicities. Furthermore, a larger scale study that includes pre-terms will aid in the comprehensive understanding of these associations.

Is islet autoimmunity related to insulin sensitivity or body weight in children of parents with type 1 diabetes?

AIMS/HYPOTHESIS

It has been suggested that metabolic demand and insulin resistance play a role in the development of type 1 diabetes, including the onset of autoimmunity. The aim of the present study was to determine whether insulin demand is increased in children with islet autoantibodies.

METHODS

BMI standard deviation score (BMI-SDS) was measured from 2 years of age in 1,650 prospectively followed children of mothers or fathers with type 1 diabetes, including 135 who developed persistent islet autoantibodies. HOMA of insulin resistance (HOMA-IR) was determined using fasting samples from 777 of the children starting from age 5 years.

RESULTS

An increased HOMA-IR was associated with female sex (p = 0.0004), older age (p < 0.0001) and increased BMI-SDS (p < 0.0001). Children with islet autoantibodies did not have an increased HOMA-IR compared with age-matched islet autoantibody-negative children (age 8 years: mean 0.61 vs mean 0.72, respectively, p = 0.21; age 11 years: mean 0.96 vs mean 1.21, respectively, p = 0.07). Furthermore, after correction for age and sex, autoantibody positivity was associated with decreased HOMA-IR values (p = 0.01). BMI-SDS was similar between islet autoantibody-positive and -negative children at age 2 (mean 0.07 vs mean 0.16, respectively), 5 (mean 0.06 vs 0.08, respectively), 8 (mean - 0.09 vs mean 0.02, respectively), and 11 years (mean 0.22 vs mean 0.16, respectively) and similar to that of national reference values.

CONCLUSIONS/INTERPRETATION

Islet autoantibody-positive children in the BABYDIAB cohort are not insulin resistant and do not have an increased BMI around and early after islet autoantibody seroconversion. These findings are inconsistent with the notion that insulin resistance is a risk factor for islet autoimmunity.

The Environmental Determinants of Diabetes in the Young (TEDDY) Study

The etiology of type 1 diabetes (T1D) remains unknown, but a growing body of evidence points to infectious agents and/or components of early childhood diet. The National Institutes of Health has established the TEDDY Study consortium of six clinical centers in the United States and Europe and a data coordinating center to identify environmental factors predisposing to, or protective against, islet autoimmunity and T1D. From 2004-2009, TEDDY will screen more than 360,000 newborns from both the general population and families already affected by T1D to identify an estimated 17,804 children with high-risk HLA-DR,DQ genotypes. Of those, 7,801 (788 first-degree relatives and 7,013 newborns with no family history of T1D) will be enrolled in prospective follow-up beginning before the age of 4.5 months. As of May 2008, TEDDY has screened more than 250,000 newborns and enrolled nearly 5,000 infants--approximately 70% of the final cohort. Participants are seen every 3 months up to 4 years of age, with subsequent visits every 6 months until the subject is 15 years of age. Blood samples are collected at each visit for detection of candidate infectious agents and nutritional biomarkers; monthly stool samples are collected for infectious agents. These samples are saved in a central repository. Primary endpoints include (1) appearance of one or more islet autoantibodies (to insulin, GAD65 or IA-2) confirmed at two consecutive visits; (2) development of T1D. By age 15, an estimated 800 children will develop islet autoimmunity and 400 will progress to T1D; 67 and 27 children have already reached these endpoints.

Children developing type 1 diabetes before 6 years of age have increased linear growth independent of HLA genotypes

AIMS/HYPOTHESIS

High birthweight and increased childhood growth are risk factors for type 1 diabetes. Relative birthweight is associated with HLA genotypes that confer a high risk of diabetes. Our aims were to test whether young children prior to clinical onset of type 1 diabetes have increased: (1) birthweight or birth length standard deviation scores (SDS); (2) height development SDS; or (3) BMI SDS during first 18 months of life and whether these parameters are related to HLA genotypes or mid-parental height (MPH).

METHODS

Birthweight, birth length, weight and height were obtained from 58 type 1 diabetes children and 155 controls matched for HLA or not in the Diabetes Prediction in Skåne study.

RESULTS

Birth length SDS corrected for MPH was increased in children developing diabetes compared with all (p < 0.048) and with non-HLA- (p < 0.050) but not with HLA-matched controls. Children developing diabetes had increased height gain at 0 to 18 months of age (p < 0.005). Diabetic children were significantly taller from 6 to 18 months of age when correcting for MPH compared with non-HLA-matched as well as HLA-matched controls, but BMI was not increased.

CONCLUSIONS/INTERPRETATION

Birth length SDS was associated with diabetes risk HLA. When corrected for MPH, children developing diabetes were taller at birth than non-HLA- but not taller than HLA-matched controls. Diabetic children had increased MPH-corrected height up to 18 months of age compared with both HLA- and non-HLA-matched controls. High-risk HLA affects prenatal growth, but other factors may explain the increased postnatal linear growth in children developing diabetes.

Maternal type 1 diabetes reduces the risk of islet autoantibodies: relationships with birthweight and maternal HbA(1c)

AIMS/HYPOTHESIS

The risk of type 1 diabetes is reduced in the children of mothers with type 1 diabetes compared with children of fathers with type 1 diabetes. We asked whether children of mothers with type 1 diabetes also have a decreased risk of developing islet autoantibodies, and which factors associated with maternal diabetes contribute to a reduced islet autoantibody risk in offspring.

METHODS

Singleton offspring of a mother (n = 1,008) or father with type 1 diabetes (n = 578) from the BABYDIAB study were included. Children were followed from birth for the development of islet autoantibodies defined as two or more autoantibodies to insulin, glutamic acid decarboxylase or insulinoma antigen 2 in two or more blood samples.

RESULTS

Islet autoantibody risk was lower in children of mothers with type 1 diabetes (5 year risk, 3.2% vs 5.7% in children of fathers with type 1 diabetes; p = 0.04). Among factors that differed between pregnancies from mothers with and without type 1 diabetes, birthweight was associated with islet autoantibody risk. Risk was reduced in children with birthweights in the lower (adjusted HR 0.33; 95% CI 0.14-0.75; p = 0.009) and upper (HR 0.45; 95% CI 0.21-0.97; p = 0.04) tertiles compared with the middle tertile. A sub-analysis of maternal HbA(1c) suggested that moderately elevated third trimester maternal HbA(1c) was also associated with a reduced islet autoantibody risk in children of mothers with type 1 diabetes (5.7-7%; HR 0.38; 95% CI 0.15-0.96; p = 0.04 vs children of mothers with HbA(1c) < 5.7%).

CONCLUSIONS/INTERPRETATION

The risk of islet autoimmunity is modified by maternally influenced events such as birthweight.