Diagnosis of gestational diabetes mellitus: it is time for international consensus

Routine screening for gestational diabetes: a review

PURPOSE OF REVIEW

Rates of gestational diabetes mellitus (GDM) throughout the world continue to increase associated with the increasing rates of obesity. Given this epidemiologic burden, the importance of proper screening, diagnosis, and management cannot be understated. This review focuses on the current screening guidelines utilized throughout the world and new data recently published regarding the most optimal screening techniques and future directions for research.

RECENT FINDINGS

Despite unanimous opinion that GDM warrants screening, the optimal screening regimen remains controversial. Notably, in the United States per the consensus recommendation by the American College of Obstetrics and Gynecology and the Society for Maternal-Fetal Medicine, a 2-step screening approach is often used. Recently, there have been multiple studies published that have compared the 1-step and 2-step screening process with respect to GDM incidence and perinatal outcomes. These new findings are summarized below.

SUMMARY

Utilization of the 1-step screening as opposed to the 2-step screening results in an increased diagnosis of GDM without significant population level benefit in outcomes. However, these studies remain underpowered to allow for meaningful comparison of outcomes in those diagnosed with GDM.

Guidelines and Recommendations for Laboratory Analysis in the Diagnosis and Management of Diabetes Mellitus

BACKGROUND

Numerous laboratory tests are used in the diagnosis and management of diabetes mellitus. The quality of the scientific evidence supporting the use of these assays varies substantially.

APPROACH

An expert committee compiled evidence-based recommendations for laboratory analysis in screening, diagnosis, or monitoring of diabetes. The overall quality of the evidence and the strength of the recommendations were evaluated. The draft consensus recommendations were evaluated by invited reviewers and presented for public comment. Suggestions were incorporated as deemed appropriate by the authors (see Acknowledgments). The guidelines were reviewed by the Evidence Based Laboratory Medicine Committee and the Board of Directors of the American Association for Clinical Chemistry and by the Professional Practice Committee of the American Diabetes Association.

CONTENT

Diabetes can be diagnosed by demonstrating increased concentrations of glucose in venous plasma or increased hemoglobin A1c (HbA1c) in the blood. Glycemic control is monitored by the people with diabetes measuring their own blood glucose with meters and/or with continuous interstitial glucose monitoring (CGM) devices and also by laboratory analysis of HbA1c. The potential roles of noninvasive glucose monitoring, genetic testing, and measurement of ketones, autoantibodies, urine albumin, insulin, proinsulin, and C-peptide are addressed.

SUMMARY

The guidelines provide specific recommendations based on published data or derived from expert consensus. Several analytes are found to have minimal clinical value at the present time, and measurement of them is not recommended.

Randomized controlled trial of prepregnancy lifestyle intervention to reduce recurrence of gestational diabetes mellitus

BACKGROUND

Preconception lifestyle intervention holds potential for reducing gestational diabetes mellitus, but clinical trial data are lacking.

OBJECTIVE

This study aimed to determine the effects of a prepregnancy weight loss intervention on gestational diabetes mellitus recurrence in women with overweight/obesity and previous gestational diabetes mellitus.

STUDY DESIGN

A 2-site, randomized controlled trial comparing a prepregnancy lifestyle intervention with educational control was conducted between December 2017 and February 2022. A total of 199 English- and Spanish-speaking adults with overweight/obesity and previous gestational diabetes mellitus were randomized to a 16-week prepregnancy lifestyle intervention with ongoing treatment until conception or educational control. The primary outcome was gestational diabetes mellitus recurrence. Analyses excluded 6 participants who conceived but did not have gestational diabetes mellitus ascertained by standard methods.

RESULTS

In the 63 (33%) women who conceived and had gestational diabetes mellitus ascertained (Ns=38/102 [37%] intervention vs 25/91 [28.0%] control; P=.17), those in the intervention group had significantly greater weight loss at 16 weeks compared with controls (4.8 [3.4-6.0] vs 0.7 [-0.9 to 2.3] kg; P=.001) and a greater proportion lost ≥5% of body weight (50.0% [17/34] vs 13.6% [3/22]; P=.005). There was no significant difference in the incidence of gestational diabetes mellitus recurrence between the intervention (57.9% [ns=23/38]) and the control group (44.0% [ns=11/25]; odds ratio, 1.8 [0.59-5.8]). Independent of group, greater prepregnancy weight loss predicted 21% lower odds of gestational diabetes mellitus recurrence (odds ratio, 0.79 [0.66-0.94]; P=.008). A ≥5% weight loss before conception reduced the odds of gestational diabetes mellitus recurrence by 82% (odds ratio, 0.18 [0.04-0.88]; P=.03).

CONCLUSION

Lifestyle intervention produced considerable prepregnancy weight loss but did not affect gestational diabetes mellitus rates. Given that the conception rate was 50% lower than expected, this study was underpowered.

Guidelines and Recommendations for Laboratory Analysis in the Diagnosis and Management of Diabetes Mellitus

BACKGROUND

Numerous laboratory tests are used in the diagnosis and management of diabetes mellitus. The quality of the scientific evidence supporting the use of these assays varies substantially.

APPROACH

An expert committee compiled evidence-based recommendations for laboratory analysis in screening, diagnosis, or monitoring of diabetes. The overall quality of the evidence and the strength of the recommendations were evaluated. The draft consensus recommendations were evaluated by invited reviewers and presented for public comment. Suggestions were incorporated as deemed appropriate by the authors (see Acknowledgments). The guidelines were reviewed by the Evidence Based Laboratory Medicine Committee and the Board of Directors of the American Association of Clinical Chemistry and by the Professional Practice Committee of the American Diabetes Association.

CONTENT

Diabetes can be diagnosed by demonstrating increased concentrations of glucose in venous plasma or increased hemoglobin A1c (Hb A1c) in the blood. Glycemic control is monitored by the people with diabetes measuring their own blood glucose with meters and/or with continuous interstitial glucose monitoring (CGM) devices and also by laboratory analysis of Hb A1c. The potential roles of noninvasive glucose monitoring, genetic testing, and measurement of ketones, autoantibodies, urine albumin, insulin, proinsulin, and C-peptide are addressed.

SUMMARY

The guidelines provide specific recommendations based on published data or derived from expert consensus. Several analytes are found to have minimal clinical value at the present time, and measurement of them is not recommended.

Gut Microbiota Associated with Gestational Health Conditions in a Sample of Mexican Women

Gestational diabetes (GD), pre-gestational diabetes (PD), and pre-eclampsia (PE) are morbidities affecting gestational health which have been associated with dysbiosis of the mother's gut microbiota. This study aimed to assess the extent of change in the gut microbiota diversity, short-chain fatty acids (SCFA) production, and fecal metabolites profile in a sample of Mexican women affected by these disorders. Fecal samples were collected from women with GD, PD, or PE in the third trimester of pregnancy, along with clinical and biochemical data. Gut microbiota was characterized by high-throughput DNA sequencing of V3-16S rRNA gene libraries; SCFA and metabolites were measured by High-Pressure Liquid Chromatography (HPLC) and (Fourier Transform Ion Cyclotron Mass Spectrometry (FT-ICR MS), respectively, in extracts prepared from feces. Although the results for fecal microbiota did not show statistically significant differences in alfa diversity for GD, PD, and PE concerning controls, there was a difference in beta diversity for GD versus CO, and a high abundance of Proteobacteria, followed by Firmicutes and Bacteroidota among gestational health conditions. DESeq2 analysis revealed bacterial genera associated with each health condition; the Spearman's correlation analyses showed selected anthropometric, biochemical, dietary, and SCFA metadata associated with specific bacterial abundances, and although the HPLC did not show relevant differences in SCFA content among the studied groups, FT-ICR MS disclosed the presence of interesting metabolites of complex phenolic, valeric, arachidic, and caprylic acid nature. The major conclusion of our work is that GD, PD, and PE are associated with fecal bacterial microbiota profiles, with distinct predictive metagenomes.

Protocol for a randomized controlled trial of pre-pregnancy lifestyle intervention to reduce recurrence of gestational diabetes: Gestational Diabetes Prevention/Prevención de la Diabetes Gestacional

BACKGROUND

Gestational diabetes mellitus (GDM) is associated with several maternal complications in pregnancy, including preeclampsia, preterm labor, need for induction of labor, and cesarean delivery as well as increased long-term risks of type 2 diabetes, metabolic syndrome, and cardiovascular disease. Intrauterine exposure to GDM raises the risk for complications in offspring as well, including stillbirth, macrosomia, and birth trauma, and long-term risk of metabolic disease. One of the strongest risk factors for GDM is the occurrence of GDM in a prior pregnancy. Preliminary data from epidemiologic and bariatric surgery studies suggest that reducing body weight before pregnancy can prevent the development of GDM, but no adequately powered trial has tested the effects of a maternal lifestyle intervention before pregnancy to reduce body weight and prevent GDM recurrence.

METHODS

The principal aim of the Gestational Diabetes Prevention/Prevención de la Diabetes Gestacional is to determine whether a lifestyle intervention to reduce body weight before pregnancy can reduce GDM recurrence. This two-site trial targets recruitment of 252 women with overweight and obesity who have previous histories of GDM and who plan to have another pregnancy in the next 1-3 years. Women are randomized within site to a comprehensive pre-pregnancy lifestyle intervention to promote weight loss with ongoing treatment until conception or an educational control group. Participants are assessed preconceptionally (at study entry, after 4 months, and at brief quarterly visits until conception), during pregnancy (at 26 weeks' gestation), and at 6 weeks postpartum. The primary outcome is GDM recurrence, and secondary outcomes include fasting glucose, biomarkers of cardiometabolic disease, prenatal and perinatal complications, and changes over time in weight, diet, physical activity, and psychosocial measures.

DISCUSSION

The Gestational Diabetes Prevention /Prevención de la Diabetes Gestacional is the first randomized controlled trial to evaluate the effects of a lifestyle intervention delivered before pregnancy to prevent GDM recurrence. If found effective, the proposed lifestyle intervention could lay the groundwork for shifting current treatment practices towards the interconception period and provide evidence-based preconception counseling to optimize reproductive outcomes and prevent GDM and associated health risks.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02763150 . Registered on May 5, 2016.

Gestational Diabetes in the Arab Gulf Countries: Sitting on a Land-Mine

Type 2 diabetes mellitus (T2DM) has become a modern-day plague by reaching epidemic levels throughout the world. Due to its similar pathogenesis, gestational diabetes (GDM) increases in parallel to T2DM. The prevalence of T2DM (3.9–18.3%) and GDM (5.1–37.7%) in countries of the Arab Gulf are amongst the highest internationally, and they are still rising precipitously. This review traces the reasons among the Arab nations for (a) the surge of T2DM and GDM and (b) the failure to contain it. During the last five decades, the massive oil wealth in many Arab countries has led to the unhealthy lifestyle changes in physical activity and diet. The excess consumption of calories turned the advantageous genes, originally selected for the famine-like conditions, detrimental: fueling obesity and insulin resistance. Despite genetic differences in these populations, GDM—a marker for future obesity and T2DM—can overcome this scourge of T2DM through active follow-up and screening after delivery. However, the health policies of most Arab countries have fallen short. Neglecting this unique chance will miss an irreplaceable opportunity to turn the tide of the T2DM and obesity epidemic in the Middle Eastern Arab Gulf countries—as well as globally.

Comparison of Venous and Capillary Sampling in Oral Glucose Testing for the Diagnosis of Gestational Diabetes Mellitus: A Diagnostic Accuracy Cross-Sectional Study Using Accu-Chek Inform II

Gestational diabetes mellitus (GDM) is a common complication with negative impacts on mother and child. The primary aim of this study was to examine whether plasma glucose cutoffs for GDM diagnosis based on venous sampling can be replaced by cutoffs based on capillary sampling. A prospective cross-sectional study was performed at an antenatal care clinic including 175 pregnant women undergoing an oral glucose tolerance test (OGTT). Duplicate samples were collected by capillary and venous puncture while fasting and 1 h and 2 h after an OGTT. Both samples were analyzed on Accu-Chek Inform II. The cutoffs for a GDM diagnosis using capillary samples were corrected from 5.1 to 5.3 mmol/L for the fasting sample, from 10.0 to 11.1 mmol/L for the 1 h sample, and from 8.5 to 9.4 mmol/L for the 2-h sample using half of the dataset. Applying these cutoffs to the remaining dataset resulted in a sensitivity, specificity, and accuracy of 85.0%, 95.0%, and 90.3%, respectively, with a positive predictive value (PPV) of 83%, an negative predictive value (NPV) of 96%, and a positive negative likelihood ratio (LHR) of 16.4 using capillary sampling for the GDM diagnosis at fasting and 2-h after. Corrected cutoffs and capillary samples can be used for the diagnosis of GDM with maintained diagnostic accuracy using Accu-Chek Inform II.

Association of Single Nucleotide Polymorphisms of the IL-6, IL-10, and TNF-α Genes with Susceptibility to Gestational Diabetes Mellitus

Objective: To investigate any associations between the single nucleotide polymorphisms (SNPs) at the interleukin-6 (IL-6) rs1800796, interleukin-10 (IL-10) rs1800896, and the tumor necrosis factor-alpha (TNF-α) rs1800629 loci with gestational diabetes mellitus (GDM) susceptibility. Materials and Methods: A total of 242 GDM patients and 242 healthy controls were enrolled in this study. The genotypes of the IL-6 rs1800796, IL-10 rs1800896, and TNF-α rs1800629 loci were analyzed by Sanger sequencing. Interactions among these SNPs were analyzed through multifactor dimensionality reduction. Results: Women with the IL-6 rs1800796 G allele had a higher GDM susceptibility risk than those with the C allele (odds ratio [OR] = 1.44, 95% confidence interval [CI]: 1.10-1.90, p = 0.010). Women with the IL-10 rs1800896 C allele had a higher risk of GDM susceptibility than those with the T allele (OR = 2.94, 95% CI: 1.87-4.63, p < 0.001). Women with the TNF-α rs1800629 A allele had a higher risk of susceptibility to GDM than those with the G allele (OR = 3.73, 95% CI: 2.25-6.18, p < 0.001). The plasma levels of IL-6 and TNF-α in GDM patients were significantly higher than those in the control group, and the levels of IL-10 were significantly lower than those in the control group (p < 0.001). Women with the IL-6 rs1800796 CG/GG genotypes had higher plasma IL-6 levels than those with the CC genotype (p < 0.05). Women with the IL-10 rs1800896 TT genotype had higher IL-10 levels than those with the TC/CC genotypes (p < 0.05), and those with the TNF-α rs1800629 GA/AA genotypes had higher TNF-α levels than those with the GG genotype (p < 0.05). Conclusion: The results of this study show that the IL-6 rs1800796 G allele, the IL-10 rs1800896 C allele, and the TNF-α rs1800629 A allele are significantly associated with an increased risk of susceptibility to GDM.

Diet and Nutritional Interventions with the Special Role of Myo-Inositol in Gestational Diabetes Mellitus Management. An Evidence-Based Critical Appraisal

BACKGROUND

Gestational Diabetes Mellitus (GDM), defined as glucose intolerance with onset or first recognition during pregnancy, represents one of the most common maternal-fetal complications during pregnancy and it is associated with poor perinatal outcomes. To date, GDM is a rising condition over the last decades coinciding with the ongoing epidemic of obesity and Type 2 Diabetes Mellitus (T2DM).

OBJECTIVE

The aim of this review is to discuss the role of diet and nutritional interventions in preventing GDM with the explanation of the special role of myo-inositol (MI) in this matter.

METHODS

We performed an overview of the most recent literature data on the subject with particular attention to the effectiveness of diet and nutritional interventions in the prevention of GDM with the special role of MI.

RESULTS

Nutritional intervention and physical activity before and during pregnancy are mandatory in women affected by GDM. Moreover, the availability of insulin-sensitizers such as different forms of inositol has dramatically changed the scenario, allowing the treatment of several metabolic diseases, such as those related to glucose dysbalance. Although the optimal dose, frequency, and form of MI administration need to be further investigated, diet supplementation with MI appears to be an attractive alternative for the GDM prevention as well as for the reduction of GDM-related complications.

CONCLUSIONS

More studies should be conducted to prove the most effective nutritional intervention in GDM. Regarding the potential effectiveness of MI, further evidence in multicenter, randomized controlled trials is needed to draw firm conclusions.

Systematic review and meta-analysis of diagnosing gestational diabetes mellitus with one-step or two-step approaches and associations with adverse pregnancy outcomes

BACKGROUND

There is an ongoing discussion about the optimal diagnostic strategy for gestational diabetes mellitus (GDM).

OBJECTIVE

To assess the magnitude of the association between GDM diagnosed with the one-step (International Association of Diabetes and Pregnancy Study Groups criteria) or two-step (Carpenter and Coustan criteria) approach and selected adverse pregnancy outcomes.

SEARCH STRATEGY

Five electronic databases were searched up to October 2017 using Medical Subject Headings for each adverse outcome combined with the term "gestational diabetes."

SELECTION CRITERIA

Observational studies assessing the one-step versus the two-step diagnostic approach in GDM.

DATA COLLECTION AND ANALYSIS

Relative risks were extracted and random-effects models were used to estimate pooled relative risks (RRs).

MAIN RESULTS

A total of 41 663 participants from nine studies were included. Gestational diabetes mellitus was significantly associated with pre-eclampsia (RR 1.68 vs RR 1.77), cesarean delivery (RR 1.28 vs RR 1.33), and large for gestational age (RR 1.44 vs RR 1.68) when diagnosed with the one-step versus the two-step approach. A one-step diagnosis also increased the risks of neonatal intensive care unit admission and gestational hypertension, whereas a two-step diagnosis increased the incidence of macrosomia.

CONCLUSIONS

Women with GDM diagnosed with either the one-step or the two-step approach were at increased risk for selected adverse pregnancy outcomes. The associations with the two-step method were slightly stronger.

Bimodal glucose distribution in Asian Indian pregnant women: Relevance in gestational diabetes mellitus diagnosis

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Pregnant Asian Indian women have bimodality in plasma glucose distribution.

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Bimodality is evident even in very young pregnant women of age 18–23 years.

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Glucose cut points may suggest thresholds for gestational diabetes diagnosis.

Aims

Presence of bimodality in plasma glucose distribution (BPG) and its relevance for gestational diabetes mellitus (GDM) diagnosis were studied in Asian Indian pregnant women.

Methods

Fasting (FPG) and two hour plasma glucose (2-h PG) values of oral glucose tolerance tests performed in 36,530 pregnant women for GDM screening (2006–16 period), were analyzed for BPG. A unimodal normal and a mixture of two normal distributions were fitted to log-transformed FPG and 2-h PG data. The mixture model was compared to unimodal model for BPG using likelihood ratio test (LRT) and the comparison was further verified by bootstrapping. The cut points of the two normal distribution curves in the mixture models of FPG and 2-h PG were noted.

Results

Fasting and 2-h PG distribution was bimodal in all pregnant women. The comparison of mixture and unimodal models using LRT revealed p value <0.001 in all age groups. The cut points for FPG and 2-h PG were 5.81 mmol/L (95% CI: 5.69–5.92) and 8.41 mmol/l (95% CI: 8.09–8.75) respectively.

Conclusion

BPG is noted for both FPG and 2-hPG in Asian Indian pregnant women. The cutpoints of normal distribution curves are close to threshold values for FPG and 2-h PG proposed in NICE (National Institute for health and Care Excellence) and IADPSG (International Association of Diabetes and Pregnancy Study Group) GDM diagnostic criteria respectively. Further research on BPG in pregnant women of racial groups with high GDM prevalence, is likely to be of value in GDM diagnosis.

Consensus in Gestational Diabetes MELLITUS: Looking for the Holy Grail

The world's pre-eminent diabetes, obstetric, endocrine, and health organizations advocate a plethora of diverse algorithms for the screening, diagnosis, management, and follow-up of gestational diabetes mellitus (GDM). Additionally, there are regional recommendations of local health societies. Several of these proposals for GDM are contentious because some of them were developed from unscientific studies, based on expert-opinion, catered to preserve resources, and subjectively modified for convenience. Due to the wide variety of choices available, the approach to GDM can be extremely diverse even within the same hospital. This lack of consensus creates major problems in addressing prevalence, complications, efficacy of treatment, and follow-up of GDM. Moreover, it becomes nearly impossible to compare the numerous studies. Furthermore, the lack of consensus confuses the health care providers of obstetric health who look to the experts for guidance. Therefore, a clear, objective, "evidence-based" global approach, which is simple, easy to follow, and validated by corroborative research, is crucial. We contend that, despite decades of research, a single acceptable global guideline is not yet on the horizon.

Excessive Neutrophil Activity in Gestational Diabetes Mellitus: Could It Contribute to the Development of Preeclampsia?

Gestational diabetes mellitus is a transient form of glucose intolerance occurring during pregnancy. Pregnancies affected by gestational diabetes mellitus are at risk for the development of preeclampsia, a severe life threatening condition, associated with significant feto-maternal morbidity and mortality. It is a risk factor for long-term health in women and their offspring. Pregnancy has been shown to be associated with a subliminal degree of neutrophil activation and tightly regulated generation of neutrophil extracellular traps (NETs). This response is excessive in cases with preeclampsia, leading to the presence of large numbers of NETs in affected placentae. We have recently observed that circulatory neutrophils in cases with gestational diabetes mellitus similarly exhibit an excessive pro-NETotic phenotype, and pronounced placental presence, as detected by expression of neutrophil elastase. Furthermore, exogenous neutrophil elastase liberated by degranulating neutrophils was demonstrated to alter trophoblast physiology and glucose metabolism by interfering with key signal transduction components. In this review we examine whether additional evidence exists suggesting that altered neutrophil activity in gestational diabetes mellitus may contribute to the development of preeclampsia.

Screening for gestational diabetes in Tuscany, Italy. A population study

AIMS

According to current Italian guidelines, only women at higher risk of gestational diabetes (GDM) are eligible for receiving a glucose tolerance test (OGTT) during pregnancy. This study evaluates the compliance to national guidelines, additionally proposing an algorithm able to identify women with GDM.

METHODS

The study included 23,270 pregnant women aged >15yr, resident in Tuscany, a region in central Italy, delivering in year 2015, identified by certificates of care at delivery. Eligibility to screening was evaluated by fulfillment to regional guidelines recommending a 2-h-75g-OGTT only in presence of risk factors. Additionally, a validated algorithm is proposed to diagnose GDM from regional administrative databases.

RESULTS

Glucose tolerance was tested in 79.2% of women. Eligibility criteria were fulfilled in 55.6% of OGTT performers and in 40.2% of those who didn't perform any OGTT. Performers' rate increased with age, body weight, higher education degree and in those followed by a well defined clinical setting. Housewives and students had a lower chance of receiving an OGTT. Algorithm identified GDM in 11% of women, ranging from 14% among eligible and 7% among non-eligible ones.

CONCLUSION

Selective screening for GDM is not being currently applied in Tuscany. Despite the percentage of eligible women by national guidelines was 55%, the rate of those who performed the screening was about 80%, with a 40% of low risk women continuing to be screened. Moreover, GDM rate, calculated by algorithm, was relatively large (7%) among non-eligible women, suggesting the need of universal glucose screening to adequately capture all GDM cases.

Application of One-Step IADPSG Versus Two-Step Diagnostic Criteria for Gestational Diabetes in the Real World: Impact on Health Services, Clinical Care, and Outcomes

PURPOSE OF REVIEW

This paper seeks to summarize the impact of the one-step International Association of Diabetes and Pregnancy Study Groups (IADPSG) versus the two-step gestational diabetes mellitus (GDM) criteria with regard to prevalence, outcomes, healthcare delivery, and long-term maternal metabolic risk.

RECENT FINDINGS

Studies demonstrate a 1.03-3.78-fold rise in the prevalence of GDM with IADPSG criteria versus baseline criteria. Women with GDM by IADPSG criteria have more adverse pregnancy outcomes than women with normal glucose tolerance (NGT). Treatment of GDM by IADPSG criteria may be cost effective. Use of the fasting glucose as a screen before the 75-g oral glucose tolerance test to rule out GDM with fasting plasma glucose (FPG) < 4.4 (80 mg/dl) and rule in GDM with FPG ≥ 5.1 mmol/l (92 mg/dl) reduces the need for OGTT by 50% and its cost and inconvenience. The prevalence of postpartum abnormal glucose metabolism is higher for women with GDM diagnosed by IADPSG criteria versus that for women with NGT. Data support the use of IADPSG criteria, if the cost of diagnosis and treatment can be controlled and if lifestyle can be optimized to reduce the risk of future diabetes.

Gestational Diabetes Mellitus Is Associated with Altered Neutrophil Activity

Gestational diabetes mellitus (GDM) is a unique form of glucose intolerance, in that it is transient and solely occurs in pregnancy. Pregnancies with GDM are at high risk of developing preeclampsia (PE), a leading cause of fetal and maternal morbidity or mortality. Since PE is associated with excessive activation of circulatory neutrophils and occurrence of neutrophil extracellular traps (NETs) in affected placentae, we examined these features in cases with GDM, as this could be a feature linking the two conditions. Our data indicate that neutrophil activity is indeed altered in GDM, exhibiting pronounced activation and spontaneous generation of NETs by isolated neutrophils in in vitro culture. In this manner, GDM may similarly affect neutrophil behavior and NET formation as witnessed in other forms of diabetes, with the addition of the physiological changes mediated by pregnancy. Since circulatory TNF-α levels are elevated in cases with GDM, a feature also observed in this study, we examined whether this pro-inflammatory cytokine contributed to neutrophil activation. By using infliximab, a clinically utilized TNF-α antagonist, we observed that the pro-NETotic effect of GDM sera was significantly reduced. We also detected pronounced neutrophil infiltrates in placentae from GDM cases. The occurrence of NETs in these tissues is suggested by the extracellular co-localization of citrullinated histones and myeloperoxidase. In addition, elevated neutrophil elastase (NE) mRNA and active enzymatic protein were also detected in such placentae. This latter finding could be important in the context of previous studies in cancer or diabetes model systems, which indicated that NE liberated from infiltrating neutrophils enters surrounding cells, altering cell signaling by the degradation of IRS1. These findings could potentiate the underlying inflammatory response process in GDM and possibly open an avenue for the therapeutic interventions in gestational hyperglycemia.

Randomized Face-to-Face vs. Home Exercise Interventions in Pregnant Women with Gestational Diabetes

OBJECTIVES

Evaluate effects of a theoretically-based, semi-intensive (Face-to-Face; F2F) exercise intervention and minimum-contact (Home) exercise intervention to the standard care (Control) on exercise, its motivational determinants, blood glucose levels, and insulin use of pregnant women with gestational diabetes mellitus (GDM).

DESIGN

Randomized control trial with two intervention arms and control (standard care).

METHOD

Participants (N=65) were randomized to a Control (standard prenatal care/GDM dietary counseling), Home (standard care + phone education/support + home exercise), or F2F (standard care + on-site education/support + guided exercise with instructor on 2 days/week) group from ~20 weeks gestation to delivery. Assessments of exercise and motivational determinants were obtained at baseline (20-weeks gestation) and follow-up (32-weeks gestation). Blood glucose levels (fasting/postprandial mg/dL) and insulin use were extrapolated from medical records.

RESULTS

At the 32-week follow-up, the F2F group had significantly higher exercise min, pedometer steps/day, and motivational determinants (attitude, subjective norm, perceived control, intention) than controls (p's < .05) and significantly higher exercise min and subjective norm than the Home group (p's < .05); these effect sizes were medium-large (η2 = .11-.23). There was a medium effect (η2 = .13) on postprandial blood glucose at 36-weeks gestation with the F2F group having lower values than controls. Although not significant, the F2F group started insulin later (33 weeks gestation) than the Home (27 weeks) and Control (31 weeks) groups.

CONCLUSION

A theoretically-based, F2F exercise intervention has multiple health benefits and may be the necessary approach for promoting exercise motivation and behavior among GDM women.

Impact of Implementing Preanalytical Laboratory Standards on the Diagnosis of Gestational Diabetes Mellitus: A Prospective Observational Study

BACKGROUND

Gestational diabetes mellitus (GDM) is associated with adverse pregnancy outcomes, but risk is reduced with identification and early treatment. Glucose measurements are affected by preanalytical sample handling, such as temperature of storage, phlebotomy-analysis interval, and use of a glycolysis inhibitor. We evaluated glucose concentrations and the incidence of GDM after strict implementation of the American Diabetes Association (ADA) preanalytical guidelines, compared with usual hospital conditions.

METHODS

Women screened selectively for GDM at 24-32 weeks' gestation were recruited at their convenience before a 75-g oral glucose tolerance test. Paired samples were taken: the first sample followed ADA recommendations and was transferred to the laboratory on an iced slurry for immediate separation and analysis (research conditions), and the second sample was not placed on ice and was transferred according to hospital practice (usual conditions).

RESULTS

Of samples from 155 women, the mean fasting, 1-h, and 2-h results were 90.0 (12.6) mg/dL [5.0 (0.7) mmol/L], 142.2 (43.2) mg/dL [7.9 (2.4) mmol/L], and 102.6 (32.4) mg/dL [5.7 (1.8) mmol/L], respectively, under research conditions, and 81 (12.6) mg/dL [4.5 (0.7) mmol/L], 133.2 (41.4) mg/dL [7.4 (2.3) mmol/L], and 99 (32.4) mg/dL [5.5 (1.8) mmol/L] under usual conditions (all P < 0.0001). GDM was diagnosed in 38.1% (n = 59) under research conditions and 14.2% (n = 22) under usual conditions (P < 0.0001). The phlebotomy-analysis interval for the fasting, 1-h, and 2-h samples was 20 (9), 17 (10), and 17 (9) min under research conditions and 162 (19), 95 (23), and 32 (19) min under usual conditions (all P < 0.0001). All cases of GDM were diagnosed on fasting or 1-h samples; the 2-h test diagnosed no additional cases.

CONCLUSIONS

Implementation of ADA preanalytical glucose sample handling recommendations resulted in higher mean glucose concentrations and 2.7-fold increased detection of GDM compared with usual hospital practices.

Obese Nondiabetic Pregnancies and High Maternal Glycated Hemoglobin at Delivery as an Indicator of Offspring and Maternal Postpartum Risks: The Prospective PEACHES Mother-Child Cohort

BACKGROUND

We investigated whether obese pregnant women negative for gestational diabetes (GDM) still experience dysglycemia, as indicated by high glycated hemoglobin (Hb A1c) at delivery, and whether this impacts offspring and long-term maternal outcomes.

METHODS

Data of 462 mother-child pairs of our prospective Programming of Enhanced Adiposity Risk in Childhood - Early Screening (PEACHES) cohort study were analyzed. Of 885 obese and normal-weight pregnancies prospectively enrolled after GDM testing according to the International Association of Diabetes and Pregnancy Study Groups criteria, 462 GDM-negative mothers and their offspring were investigated. We assessed associations of maternal Hb A1c at delivery with large-for-gestational-age (LGA) birth weights, cord-blood C-peptide, and biomarkers of glucose metabolism and inflammation in obese mothers followed for 2.9 years (median) postpartum (n = 42).

RESULTS

Cumulative distribution analysis in GDM-negative normal-weight women (n = 155) revealed that 12% had Hb A1c ≥5.7% at delivery (high Hb A1c). Among obese GDM-negative women (n = 307), 31.9% (95% CI, 26.7%-37.4%) equaled or exceeded this cutoff. In obese GDM-negative women with Hb A1c ≥5.7% (n = 98) vs <5.7% (n = 209) at delivery, newborns were more likely to be born LGA [adjusted odds ratio 3.56 (95% CI, 1.64-8.02)], and mean cordblood serum C-peptide was increased by 0.09 ng/mL (95% CI, 0.01-0.17 ng/mL). In the mothers at follow-up, mean postpartum Hb A1c, fasting glucose, high-sensitivity C-reactive protein, and fibrinogen concentrations were higher by 0.3% (95% CI, 0.1%-0.5%), 6.0 mg/dL (95% CI, 2.4-9.5 mg/dL), 6.8 mg/L (95% CI, 1.4-12.3 mg/L), and 74.9 mg/dL (95% CI, 13.6-136.2 mg/dL), respectively.

CONCLUSIONS

Increased Hb A1c in obese GDM-negative women at delivery indicates gestational dysglycemia, potentially conferring offspring and long-term maternal health risks. These findings should raise awareness as to careful monitoring of obese pregnancies. Measurement of Hb A1c at delivery could help select women who may need closer postpartum health checks.

Diabetes mellitus: The epidemic of the century

The epidemic nature of diabetes mellitus in different regions is reviewed. The Middle East and North Africa region has the highest prevalence of diabetes in adults (10.9%) whereas, the Western Pacific region has the highest number of adults diagnosed with diabetes and has countries with the highest prevalence of diabetes (37.5%). Different classes of diabetes mellitus, type 1, type 2, gestational diabetes and other types of diabetes mellitus are compared in terms of diagnostic criteria, etiology and genetics. The molecular genetics of diabetes received extensive attention in recent years by many prominent investigators and research groups in the biomedical field. A large array of mutations and single nucleotide polymorphisms in genes that play a role in the various steps and pathways involved in glucose metabolism and the development, control and function of pancreatic cells at various levels are reviewed. The major advances in the molecular understanding of diabetes in relation to the different types of diabetes in comparison to the previous understanding in this field are briefly reviewed here. Despite the accumulation of extensive data at the molecular and cellular levels, the mechanism of diabetes development and complications are still not fully understood. Definitely, more extensive research is needed in this field that will eventually reflect on the ultimate objective to improve diagnoses, therapy and minimize the chance of chronic complications development.

Gestational diabetes mellitus: An update on the current international diagnostic criteria

The approach to screening and diagnosis of gestational diabetes mellitus (GDM) around the world is disorderly. The protocols for diagnosis vary not only in-between countries, but also within countries. Furthermore, in any country, this disparity occurs in-between its hospitals and often exists within a single hospital. There are many reasons for these differences. There is the lack of an international consensus among preeminent health organizations (e.g., American College of Gynecologists and World Health Organization). Often there is a disagreement between the country's national diabetes organization, its local health society and its regional obstetric organization with each one recommending a different option for approaching GDM. Sometimes the causes for following an alternate approach are very obvious, e.g., a resource strapped hospital is unable to follow the ivory-tower demanding recommendation of its obstetric organization. But more often than not, the rationale for following or not following a guideline, or following different guideline within the same geographic area is without any perceivable explanation. This review is an attempt to understand the problems afflicting the screening and diagnosis of GDM globally. It traces the major temporal changes in the diagnostic criteria of (1) some respected health organizations; and (2) a few selected countries. With an understanding of the reasons for this disparity, a way forward can be found to reach the ultimate goal: a single global guideline for GDM followed worldwide.

Gestational diabetes: differences between the current international diagnostic criteria and implications of switching to IADPSG

AIMS

To highlight the differences between eight international expert panel diagnostic criteria (either current or outdated but in use) for the diagnosis of gestational diabetes mellitus (GDM) and implications of switching to the International Association of Diabetes in Pregnancy Study Groups (IADPSG) criterion.

METHODS

2337 pregnant women underwent a 75-g oral glucose tolerance test as part of a universal screening protocol. The GDM prevalence and number of women classified differently were compared between the criteria of the American Diabetes Association (2003); Australasian Diabetes in Pregnancy Society (1998); the Canadian Diabetes Association, CDA (2003 & 2013); the European Association for the Study of Diabetes (1996); IADPSG (2010); the New Zealand Society for the Study of Diabetes (2004) and the World Health Organization (1999).

RESULTS

The prevalence varied from 9.2% to 45.3% with the different criteria. The IADPSG compared a) best with CDA 2013 [356(15.2%) women classified differently, (kappa, k=68.3%)] and b) worst with CDA 2003 [843 (36.1%) women classified differently, (k=21.8%)]; p<0.001.Switching to IADPSG from the original criteria would increase the prevalence 1.5-4.9 times.

CONCLUSIONS

In 2015, the various international guidelines for GDM continue to show major discrepancies in the prevalence and the women classified dissimilarly. A consensus on a single global guideline would be a giant leap forward.