Despite treatment, HbA1c ≥ 37 mmol/mol in the first trimester is associated with premature delivery among South Asian women with gestational diabetes mellitus: a retrospective cohort study

PURPOSE

To examine the effects of first-trimester HbA1c (HbA1c-FT) ≥ 37 mmol/mol on preterm birth (PTB) and large-for-gestational-age (LGA) babies in a retrospective cohort of South Asian pregnant women with gestational diabetes (GDM).

METHODS

The cohort (n = 686) was separated into two groups based on HbA1c-FT values: Group A (n = 97) and Group B (n = 589), with values of 37-46 mmol/mol (5.5-6.4%) and < 37 mmol/mol (5.5%), respectively. HbA1c-FT's independent influence on PTB and LGA babies was examined using multivariable logistic regression in groups A and B women. The reference group (Group C) included 2031 non-GDM women with HbA1c-FT < 37 mmol/mol (< 5.5%). The effects of HbA1c-FT on PTB and LGA babies in obese women in Groups A, B, and C (designated as A-ob, B-ob, and C-ob, respectively) were re-analyzed using multivariable logistic regression.

RESULTS

Group A GDM women with greater HbA1c-FT had a higher risk for PTB (aOR:1.86, 95% CI:1.10-3.14) but not LGA babies (aOR:1.13, 95%: 0.70-1.83). The risk of PTB was higher for obese women in Group A-ob: aOR 3.28 [95% CI 1.68-6.39]. However, GDM women with normal HbA1c-FT exhibited no elevated risk for PTB: Groups B and B-ob had aORs of 1.30 (95% CI 0.86-1.98) and 1.28 (95% CI 0.88-1.85) respectively.

CONCLUSIONS

South Asian GDM women with prediabetic HbA1c FT; 37-46 mmol/mol (5.5-6.4%) are more likely to deliver preterm babies despite treatment, while the risk for LGA babies was the same as non-GDM women.

Intermediate hyperglycemia in early pregnancy: A South Asian perspective

“Intermediate hyperglycemia in early pregnancy (IHEP)” refers to mild hyperglycemia detected before 24 gestational weeks (GW), satisfying the criteria for the diagnosis of gestational diabetes mellitus. Many professional bodies recommend routine screening for “overt diabetes” in early pregnancy, which identifies a significant number of women with mild hyperglycemia of undetermined significance. A literature search revealed that one-third of GDM women in South Asian countries are diagnosed before the conventional screening period of 24 GW to 28 GW; hence, they belong in the IHEP category. Most hospitals in this region diagnose IHEP by oral glucose tolerance test (OGTT) using the same criteria used for GDM diagnosis after 24 GW. There is some evidence to suggest that South Asian women with IHEP are more prone to adverse pregnancy events than women with a diagnosis of GDM after 24 GW, but this observation needs to be proven by randomized control trials. Fasting plasma glucose is a reliable screening test for GDM that can obviate the need for OGTT for GDM diagnosis among 50% of South Asian pregnant women. HbA1c in the first trimester predicts GDM in later pregnancy, but it is not a reliable test for IHEP diagnosis. There is evidence to suggest that HbA1c in the first trimester is an independent risk factor for several adverse pregnancy events. Further research to identify the patho-genetic mechanisms behind the fetal and maternal effects of IHEP is strongly recommended.

Establishing Trimester-Specific Haemoglobin A1c Reference Intervals in Pregnant Women: A retrospective study of healthy South Asian women with normal pregnancy outcomes

Objectives

This study aimed to define trimester-specific haemoglobin A1c (HbA1c) reference intervals in healthy, pregnant South Asian women.

Methods

This retrospective study was conducted at St. Stephen's Hospital, Delhi, India, between January 2011 and December 2016. Healthy pregnant women were compared to a control group of healthy non-pregnant women. Pregnant participants had term deliveries of babies with appropriate gestational weights. The HbA1c levels were calculated in terms of non-parametric 2.5 and 97.5 percentiles for women in first (T1), second (T2) and third (T3) trimester groups. Statistical tests were used to obtain the normal HbA1c reference values and were considered significant when P <0.05.

Results

This study included a total of 1,357 healthy pregnant women and a control group of 67 healthy, non-pregnant women. Pregnant women had a median HbA1c of 4.8% (4-5.5%) or 32 mmol/mol (20-39 mmol/mol); non-pregnant women had a median HbA1c of 5.1% (4-5.7%) or 29 mmol/mol (20-37 mmol/mol; P <0.001). The HbA1c levels for the T1, T2 and T3 groups were 4.9% (4.1-5.5%) or 30 mmol/mol (21-37 mmol/mol), 4.8% (4.5-5.3%) or 29 mmol/mol (20-34 mmol/mol) and 4.8% (3.9-5.6%) or 29 mmol/mol (19-38 mmol/mol), respectively. The HbA1c values were significant when comparing T1 versus T2 (P <0.001), T1 versus T3 (P = 0.002) and T1 versus the non-pregnant group (P = 0.001). However, T2 versus T3 was not significant (P = 0.111).

Conclusion

Compared to non-pregnant women, HbA1c levels were lower in pregnant women, despite women in the T2 and T3 groups having a higher body mass index than the women in the T1 and non-pregnant groups. Further research is recommended to understand the factors responsible and validate these findings.

Gestational diabetes mellitus in early pregnancy amongst Asian Indian women: Evidence for poor pregnancy outcomes despite treatment

AIM

To compare the pregnancy outcomes in women with gestational diabetes (GDM) based on the timing of diagnosis.

METHODS

This retrospective cohort study was conducted between January 2011 and September 2017 amongst 2638 Asian Indian pregnant women. The inclusion criteria included; singleton pregnancies having HbA1c <48 mmols/mol (6.5%) in the first trimester, GDM screening by 75 g OGTT using IADPSG criteria and delivery at our centre. The cohort was divided into 3 groups: Early GDM (E-GDM)-diagnosis <24 gestational weeks (Gw), Standard GDM (S-GDM)-diagnosis ≥24Gw, Non-GDM- No GDM ≥24 Gw. Multivariable logistic regression models compared the pregnancy outcomes between Non-GDM, S-GDM and E-GDM groups. A sub-group multivariable analysis was done amongst GDM women using gestational age at diagnosis both as a categorical and continuous variable.

RESULTS

Compared to Non-GDM women, the odds were higher for premature birth, large for gestational age (LGA) babies, macrosomia, Neonatal ICU(NICU) admission and lower for normal vaginal delivery in the E-GDM group, but for the S-GDM group, the risk was higher for premature birth, LGA babies, NICU admission and induction of labour. Compared to GDM women in the 24-28 Gw category significantly higher odds for premature birth and LGA babies were observed in the <14 Gw category. A continuous increase of 19% odds for premature birth with every 4 weeks decrease in gestational age at GDM diagnosis was observed.

CONCLUSIONS

Asian Indian women having a GDM diagnosis before 24Gw are at higher risk for adverse pregnancy events than those having diagnosis ≥24Gw or not having GDM.

Is HbA1c in the first trimester associated with adverse outcomes among pregnant Asian Indian women without gestational diabetes?

AIMS

The aim of this study is to determine the association of elevated HbA1c in the first trimester (HbA1c-FT) with adverse events among pregnant Asian Indian women without gestational diabetes (GDM).

METHODS

This retrospective cohort study included 1618 pregnant women who delivered at a single urban tertiary care center and had HbA1c-FT estimation between January 2011 and September 2017. Those with GDM according to a 75-g OGTT after 24 gestational weeks were excluded. Multivariable logistic regression models assessed the association between elevated HbA1c-FT and adverse events.

RESULTS

At a cutoff of ≥37 mmol/mol (5.5%), HbA1c-FT was associated with preterm birth at <37 gestational weeks (adjusted odds ratio (OR) 2.10, 95% CI 1.11-3.98). There was a continuum of risk for primary caesarean delivery with higher HbA1c-FT levels (adjusted OR per 5-mmol/mol (0.5%) increase in HbA1c-FT for primary caesarean delivery: 1.27, 95% CI 1.06-1.52). In the crude analysis, gestational hypertension was associated with HbA1c-FT, but not after adjustment for confounding factors. HbA1c-FT was not associated with other adverse events (macrosomia, large for gestational age babies, or other neonatal complications).

CONCLUSIONS

Even without GDM, the results suggest an association of HbA1c-FT with preterm birth and primary caesarian delivery among Asian Indian women.

Prevalence of 'Hyperglycemia in pregnancy' remained stable between 2006 and 2015, despite rise in conventional risk factors: A hospital based study in Delhi, North India

AIMS

Between 2006 and 2015, the trends in prevalence of Hyperglycemia in pregnancy (HIP); Gestational diabetes (GDM), Diabetes in Pregnancy (DIP), Pre existing diabetes (PDM) and GDM risk factors were studied in 30,692 pregnancies among Asian Indian women.

METHODS

GDM (n = 4089) and DIP (n = 259) diagnoses were by 75 g OGTT, while PDM (n = 103) was identified by ICD code O24. Women with DIP and PDM were grouped together as pre-gestational diabetes (PGDM n = 362). Crude and age-adjusted prevalence trend analysis by Poisson and Jointpoint regression models respectively, were done in GDM and PGDM groups.

RESULTS

During study years, the GDM prevalence by WHO 1999 and modified IADPSG criteria, showed decreasing and static trends respectively, while PGDM prevalence remained static. In a subgroup of 2560 women, mean BMI increased from 24.12 ± 4.16 in year 2011 to 25.18 ± 4.7 Kg/m² in 2015 (p < 0.014), but this rise had no impact on GDM prevalence. GDM risk factors; maternal age, gravidity ≥3, previous GDM and abortion, high income, diabetes and hypertension in family, were higher in 2011-2015 than in 2006-2010 period. On multivariate analysis, BMI was not an independent GDM risk factor.

CONCLUSION

Despite rise in conventional GDM risk factors, HIP prevalence was static for a decade among pregnant Asian Indian women.

Glycated haemoglobin in the first trimester: A predictor of gestational diabetes mellitus in pregnant Asian Indian women

AIM

To assess the efficacy of first trimester glycated hemoglobin (HbA1c-FT) in diagnosing or predicting gestational diabetes mellitus (GDM) in Asian Indian women.

METHODS

This retrospective cohort study involved 2275 women who underwent both HbA1c-FT estimation and GDM screening with a one-step 75 g oral glucose tolerance test. Receiver Operating Characteristic (ROC) curve statistics were applied to assess the discriminative ability of HbA1c-FT in GDM diagnosis. A multivariable logistic regression analysis after adjusting for plausible confounders was used to evaluate the independent effect of HbA1c-FT on GDM diagnosis.

RESULTS

The mean HbA1c-FT of GDM (n = 578) and non-GDM women (n = 1697) were 5.04 + 0.04% and 4.9 + 0.37%, respectively (p < 0.001). Compared to women with a HbA1c-FT < 5.2%, the adjusted odds ratio to develop GDM of women with an HbA1c-FT range of 5.2-5.5% and those >5.6% to develop GDM were 1.627 (p < 0.004) and 2.6 (p < 0.001), respectively. The area under the ROC curve to detect GDM was 0.606 (95% CI: 0.519-0.633 p < 0.001), but the sensitivity and specificity of the HbA1c-FT were not sufficient to diagnose, rule in or rule out GDM.

CONCLUSIONS

HbA1c-FT is an independent GDM predictor in Asian Indian women but lacks sufficient sensitivity or specificity for use as a diagnostic test.

Bimodal distribution of fasting, one and two hour post load plasma glucose in Asian Indian pregnant women without pre-gestational diabetes: Gestational age related changes

•After exclusion of pre-gestational diabetes, Asian Indian pregnant women have bimodal distribution of plasma glucose.•Bimodality is observed for fasting, 1 and 2 h post glucose load plasma glucose distribution.•Cut off values for gestational diabetes diagnosis could not identified for any glucose parameter.•In women with high gestational diabetes risk factors, the bimodality is evident before 24 weeks of gestation.•By third trimester, the bimodality is significant for all glucose parameters.

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.

Prospective purification of perivascular presumptive mesenchymal stem cells from human adipose tissue: process optimization and cell population metrics across a large cohort of diverse demographics

BACKGROUND

Adipose tissue is an attractive source of mesenchymal stem cells (MSC) as it is largely dispensable and readily accessible through minimally invasive procedures such as liposuction. Until recently MSC could only be isolated in a process involving ex-vivo culture and their in-vivo identity, location and frequency remained elusive. We have documented that pericytes (CD45-, CD146+, and CD34-) and adventitial cells (CD45-, CD146-, CD34+) (collectively termed perivascular stem cells or PSC) represent native ancestors of the MSC, and can be prospectively purified using fluorescence activated cell sorting (FACS). In this study we describe an optimized protocol that aims to deliver pure, viable and consistent yields of PSC from adipose tissue. We analysed the frequency of PSC within adipose tissue, and the effect of patient and procedure based variables on this yield.

METHODS

Within this twin centre study we analysed the adipose tissue of n = 131 donors using flow cytometry to determine the frequency of PSC and correlate this with demographic and processing data such as age, sex, BMI and cold storage time of the tissue.

RESULTS

The mean number of stromal vascular fraction (SVF) cells from 100 ml of lipoaspirate was 34.4 million. Within the SVF, mean cell viability was 83 %, with 31.6 % of cells being haematopoietic (CD45+). Adventitial cells and pericytes represented 33.0 % and 8 % of SVF cells respectively. Therefore, a 200 ml lipoaspirate would theoretically yield 23.2 million viable prospectively purified PSC - sufficient for many reconstructive and regenerative applications. Minimal changes were observed in respect to age, sex and BMI suggesting universal potential application.

CONCLUSIONS

Adipose tissue contains two anatomically and phenotypically discreet populations of MSC precursors - adventitial cells and pericytes - together referred to as perivascular stem cells (PSC). More than 9 million PSC per 100 ml of lipoaspirate can be rapidly purified to homogeneity using flow cytometry in clinically relevant numbers potentially circumventing the need for purification and expansion by culture prior to clinical use. The number and viability of PSC are minimally affected by patient age, sex, BMI or the storage time of the tissue, but the quality and consistency of yield can be significantly influenced by procedure based variables.