CGMS profile of women diagnosed as GDM by IADPSG criteria and labelled as normoglycemic by alternate criteria in early pregnancy

Postpartum glycemic and cardiometabolic profile of women testing positive for gestational diabetes mellitus by International Association of Diabetes and Pregnancy Study Groups (IADPSG) but negative by alternate criteria: Insights from CHIP-F study

OBJECTIVE

To evaluate burden of postpartum diabetes and other cardiometabolic risk factors among women who test positive for gestational diabetes mellitus (GDM) by International Association of Diabetes and Pregnancy Study Groups (IADPSG) criteria, but negative by alternate criteria.

METHODS

This prospective cross-sectional study was conducted from 2019 to 2022 and is a sub-study of the CHIP-F cohort (Cohort Study of Indian Women with Hyperglycemia in Pregnancy and their Families).

RESULTS

Study participants (n = 826; 183 with normoglycemia and 643 with GDM using IADPSG criteria) were evaluated at a median (IQR) postpartum interval of 31 (21-45) months. Using the United Kingdom National Institute of Health and Care Excellence (UK NICE), Canadian Diabetes Association (CDA), and Diabetes in Pregnancy Study Group India (DIPSI) criteria, 251 (39.0 %), 148 (23.0 %) and 384 (59.7 %) women who tested positive for GDM by IADPSG criteria, would have tested negative. The incidence of postpartum diabetes among such women was 30.4, 34.3, and 48.2 per 1000 women-years, respectively, which was significantly higher than those testing negative by both IADPSG and UK NICE (5.0 per 1000 women-years), IADPSG and CDA (9.2/1000 women-years) and IADPSG and DIPSI criteria (5.0/1000 women-years). The burden of obesity and metabolic syndrome was also significantly higher in such women.

CONCLUSIONS

We found a significant burden of postpartum diabetes and cardiometabolic risk factors among women who tested positive for GDM by IADPSG, but negative by alternate criteria. There are potential clinical implications of a "failed" diagnosis for future cardiometabolic diseases that need to be carefully examined.

Glucose levels measured with continuous glucose monitoring in uncomplicated pregnancies

INTRODUCTION

To characterize glucose levels during uncomplicated pregnancies, defined as pregnancy with a hemoglobin A1c <5.7% (<39 mmol/mol) in early pregnancy, and without a large-for-gestational-age birth, hypertensive disorders of pregnancy, or gestational diabetes mellitus (ie, abnormal oral glucose tolerance test).

RESEARCH DESIGN AND METHODS

Two sites enrolled 937 pregnant individuals aged 18 years and older prior to reaching 17 gestational weeks; 413 had an uncomplicated pregnancy (mean±SD body mass index (BMI) of 25.3±5.0 kg/m2) and wore Dexcom G6 continuous glucose monitoring (CGM) devices throughout the observed gestational period. Mealtimes were voluntarily recorded. Glycemic levels during gestation were characterized using CGM-measured glycemic metrics.

RESULTS

Participants wore CGM for a median of 123 days each. Glucose levels were nearly stable throughout all three trimesters in uncomplicated pregnancies. Overall mean±SD glucose during gestation was 98±7 mg/dL (5.4±0.4 mmol/L), median per cent time 63-120 mg/dL (3.5-6.7 mmol/L) was 86% (IQR: 82-89%), median per cent time <63 mg/dL (3.5 mmol/L) was 1.8%, median per cent time >120 mg/dL (6.7 mmol/L) was 11%, and median per cent time >140 mg/dL (7.8 mmol/L) was 2.5%. Mean post-prandial peak glucose was 126±22 mg/dL (7.0±1.2 mmol/L), and mean post-prandial glycemic excursion was 36±22 mg/dL (2.0±1.2 mmol/L). Higher mean glucose levels were low to moderately associated with pregnant individuals with higher BMIs (103±6 mg/dL (5.7±0.3 mmol/L) for BMI ≥30.0 kg/m2 vs 96±7 mg/dL (5.3±0.4 mmol/L) for BMI 18.5-<25 kg/m2, r=0.35).

CONCLUSIONS

Mean glucose levels and time 63-120 mg/dL (3.5-6.7 mmol/L) remained nearly stable throughout pregnancy and values above 140 mg/dL (7.8 mmol/L) were rare. Mean glucose levels in pregnancy trend higher as BMI increases into the overweight/obesity range. The glycemic metrics reported during uncomplicated pregnancies represent treatment targets for pregnant individuals.

Meta-analysis comparing diabetes in pregnancy study group India (DIPSI) vs the international association of the diabetes and pregnancy study groups (IADPSG) criteria for diagnosis of gestational diabetes among Indian population

Despite consensus on universal screening of women at 24-28 weeks for a diagnosis of gestational diabetes, controversy remains on an appropriate criterion. The study is aimed to find out the sensitivity and specificity of Diabetes in Pregnancy Study Group India (DIPSI) criteria compared to the International Association of the Diabetes and Pregnancy Study Groups (IADPSG) criteria for diagnosis of Gestational Diabetes Mellitus (GDM). A meta-analysis of studies comparing DIPSI as an index test to IADPSG as the reference test for diagnosing GDM was carried out. A total of 8 comparative studies were included. Pooled analysis showed a sensitivity of 0.44 [0.29 to 0.60] and specificity of 0.97 [0.94 to 0.98], which means the index test DIPSI will correctly identify only 44% of the subjects who have the disease (GDM positive) but it will also fail to identify 56% of the GDM positive subjects. Derek's funnel graph revealed fewerchances of publication bias. Though convenient, DIPSI criteria was not found to be sensitive enough for a diagnosis of GDM and missed an opportunity to improve pregnancy and subsequent long-term outcomes for a substantial number of women. Further studies should focus on comparing pregnancy outcomes for the two criteria, so that decision to adopt any criteria is more evidence-based.

Continuous Glucose Monitoring System Profile of Women Stratified Using Different Levels of Glycated Hemoglobin (HbA1c) in Early Pregnancy: A Cross-sectional Study

AIM

To evaluate the differences in the continuous glucose monitoring system (CGMS) profiles of women in early pregnancy stratified based on different HbA1c levels known to be predictive of gestational diabetes mellitus (GDM) at 24-28 weeks of gestation (≥ 5.2%) and adverse pregnancy outcomes (≥ 5.5%) in Indian women.

METHODS

We enrolled women at 8^+ 0 to 19^+ 6 weeks of gestation (early pregnancy), evaluated the glycaemic parameters of clinical interest using CGMS, and reported them per standard methodology proposed by Hernandez et al. WHO 2013 criteria were used for diagnosis of early GDM.

RESULTS

Ninety-six women were enrolled at 14.0 ± 3.2 weeks of gestation. Of these, 38 were found to have early GDM (diagnosed before 20 weeks of gestation) on evaluation. Of 96 women, 33 (34.4%) had HbA1c value ≥ 5.5% [11 (19.0%) with normoglycaemia and 22 (57.9%) with GDM]. The women with elevated HbA1c differed significantly from those with HbA1c < 5.5% for all evaluated parameters. The differences for overall women were > 10 mg/dl (0.56 mmol/l) for 1-h postprandial glucose (difference of 0.78 mmol/l), 2-h postprandial glucose (difference of 0.59 mmol/l), peak postprandial glucose (difference of 0.75 mmol/l), and 1-h postprandial glucose excursion (difference of 0.59 mmol/l). Of 58 women with normoglycaemia, 29 (50.0%) had an HbA1c value  ≥ 5.2%. In comparison, in the normoglycaemic group of women with and without HbA1c ≥ 5.2% (known to be predictive of future GDM), the results were significant for 1-h (difference of 0.44 mmol/l), 2-h (difference of 0.278 mmol/l), and peak postprandial glucose (difference of 0.35 mmol/l).

CONCLUSIONS

The results suggest that women with elevated HbA1c (≥ 5.5%) in early pregnancy significantly differ from those with HbA1c < 5.5% in all glycaemic parameters evaluated in this study, suggesting that HbA1c at this cut-off has a role to play in early pregnancy.

Continuous Glucose Monitoring System Profile of Women with Gestational Diabetes Mellitus Missed Using Isolated Fasting Plasma Glucose-Based Strategies Alternative to WHO 2013 Criteria: A Cross-Sectional Study

INTRODUCTION

The aim of the study was to evaluate the differences in the continuous glucose monitoring system (CGMS)-based glycemic parameters between women with normoglycemia and early gestational diabetes mellitus (GDM) identified on the basis of mild fasting plasma glucose elevation (FPG, 5.1-5.5 mmol/L) and/or post-load plasma glucose elevation (PLG, 1-h ≥ 10.0 mmol/L or 2-h ≥ 8.5 mmol/L).

METHODS

This cross-sectional study included women with singleton pregnancy (8⁺⁰ to 19⁺⁶ weeks of gestation) and normoglycemia or GDM per World Health Organization (WHO) 2013 criteria. We evaluated the glycemic parameters of clinical interest using blinded CGMS evaluation and reported them per standard methodology proposed by Hernandez et al. RESULTS: A total of 87 women (GDM, n = 38) were enrolled at 28.6 ± 4.5 years. Among women with GDM, 10 (26.3%) had isolated mild FPG elevation (5.1-5.5 mmol/L), 10 (26.3%) had isolated PLG elevation (1-h ≥ 10.0 mmol/L or 2-h ≥ 8.5 mmol/L), and 7 (18.4%) had a combination of both. The remaining 11 (28.9%) had elevated FPG (≥ 5.6 mmol/L) with or without PLG elevation. Thus, when an isolated FPG cutoff ≥ 5.6 mmol/L is used to diagnose GDM, 27 (71.0%) women would be perceived as normoglycemic. Such women had significantly higher CGMS parameters of clinical interest, such as 24-h mean glucose, fasting glucose, 1-h and 2-h postprandial glucose (PPG), 1-h PPG excursion, and peak PPG.

CONCLUSIONS

An isolated FPG threshold, especially the higher cutoff ≥ 5.6 mmol/L, can potentially miss a large proportion of women (nearly three-fourths) diagnosed with GDM per WHO 2013 criteria. Eventually, such women fare significantly differently from normoglycemic women in various CGMS parameters of clinical interest.