DALI: Vitamin D and lifestyle intervention for gestational diabetes mellitus (GDM) prevention: an European multicentre, randomised trial - study protocol

Implementing care for women with gestational diabetes after delivery-the challenges ahead

Gestational diabetes (GDM), defined as glucose intolerance during pregnancy, affects one in six pregnancies globally and significantly increases a woman's lifetime risk of type 2 diabetes mellitus (T2DM). Being a relatively young group, women with GDM are also at higher risk of developing diabetes related complications (e.g., cardiovascular disease, non-alcoholic fatty liver disease) later in life. Children of women with GDM are also likely to develop GDM and this perpetuates a cycle of diabetes, escalating our current pandemic of metabolic disease. The global prevalence of GDM has now risen by more than 30% over the last two decades, making it an emerging public health concern. Antepartum management of maternal glucose is unable to fully mitigate the associated lifetime cardiometabolic risk. Thus, efforts may need to focus on improving care for women with GDM during the postpartum period where prevention or therapeutic strategies could be implemented to attenuate progression of GDM to DM and its associated vascular complications. However, strategies to provide care for women in the postpartum period often showed disappointing results. This has led to a missed opportunity to halt the progression of impaired glucose tolerance/impaired fasting glucose to DM in women with GDM. In this review, we examined the challenges in the management of women with GDM after delivery and considered how each of these challenges are defined and could present as a gap in translating evidence to clinical care. We highlighted challenges related to postpartum surveillance, postpartum glucose testing strategies, postpartum risk factor modification, and problems encountered in engagement of patients/providers to implement interventions strategies in women with GDM after delivery. We reasoned that a multisystem approach is needed to address these challenges and to retard progression to DM and cardiovascular disease (CVD) in women with GDM pregnancies. This is very much needed to pave way for an improved, precise, culturally sensitive and wholistic care for women with GDM.

Vitamin D supplementation for women during pregnancy

BACKGROUND

Vitamin D supplementation during pregnancy may help improve maternal and neonatal health outcomes (such as fewer preterm birth and low birthweight babies) and reduce the risk of adverse pregnancy outcomes (such as severe postpartum haemorrhage).

OBJECTIVES

To examine whether vitamin D supplementation alone or in combination with calcium or other vitamins and minerals given to women during pregnancy can safely improve certain maternal and neonatal outcomes.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Trials Register (which includes results of comprehensive searches of CENTRAL, MEDLINE, Embase, CINAHL, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform, and relevant conference proceedings) (3 December 2022). We also searched the reference lists of retrieved studies.

SELECTION CRITERIA

Randomised and quasi-randomised trials evaluating the effect of supplementation with vitamin D alone or in combination with other micronutrients for women during pregnancy in comparison to placebo or no intervention.

DATA COLLECTION AND ANALYSIS

Two review authors independently i) assessed the eligibility of studies against the inclusion criteria, ii) assessed trustworthiness based on pre-defined criteria of scientific integrity, iii) extracted data from included studies, and iv) assessed the risk of bias of the included studies. We assessed the certainty of the evidence using the GRADE approach.

MAIN RESULTS

The previous version of this review included 30 studies; in this update, we have removed 20 of these studies to 'awaiting classification' following assessments of trustworthiness, one study has been excluded, and one new study included. This current review has a total of 10 included studies, 117 excluded studies, 34 studies in awaiting assessment, and seven ongoing studies. We used the GRADE approach to assess the certainty of the evidence. This removal of the studies resulted in evidence that was downgraded to low-certainty or very low-certainty due to study design limitations, inconsistency between studies, and imprecision. Supplementation with vitamin D compared to no intervention or a placebo A total of eight studies involving 2313 pregnant women were included in this comparison. We assessed four studies as having a low risk of bias for most domains and four studies as having high risk or unclear risk of bias for most domains. The evidence is very uncertain about the effect of supplementation with vitamin D during pregnancy compared to placebo or no intervention on pre-eclampsia (risk ratio (RR) 0.53, 95% confidence interval (CI) 0.21 to 1.33; 1 study, 165 women), gestational diabetes (RR 0.53, 95% CI 0.03 to 8.28; 1 study, 165 women), preterm birth (< 37 weeks) (RR 0.76, 95% CI 0.25 to 2.33; 3 studies, 1368 women), nephritic syndrome (RR 0.17, 95% CI 0.01 to 4.06; 1 study, 135 women), or hypercalcaemia (1 study; no cases reported). Supplementation with vitamin D during pregnancy may reduce the risk of severe postpartum haemorrhage; however, only one study reported this outcome (RR 0.68, 95% CI 0.51 to 0.91; 1 study, 1134 women; low-certainty evidence) and may reduce the risk of low birthweight; however, the upper CI suggests that an increase in risk cannot be ruled out (RR 0.69, 95% CI 0.44 to 1.08; 3 studies, 371 infants; low-certainty evidence). Supplementation with vitamin D + calcium compared to no intervention or a placebo One study involving 84 pregnant women was included in this comparison. Overall, this study was at moderate to high risk of bias. Pre-eclampsia, gestational diabetes, and maternal adverse events were not reported. The evidence is very uncertain about the effect of supplementation with vitamin D and calcium on preterm birth (RR not estimable; very low-certainty evidence) or for low birthweight (RR 1.45, 95% CI 0.14 to 14.94; very low-certainty evidence) compared to women who received placebo or no intervention. Supplementation with vitamin D + calcium + other vitamins and minerals versus calcium + other vitamins and minerals (but no vitamin D) One study involving 1298 pregnant women was included in this comparison. We assessed this study as having a low risk of bias in all domains. Pre-eclampsia was not reported. The evidence is very uncertain about the effect of supplementation with vitamin D, calcium, and other vitamins and minerals during pregnancy compared to no vitamin D on gestational diabetes (RR 0.42, 95% CI 0.10 to 1.73; very low-certainty evidence), maternal adverse events (hypercalcaemia no events and hypercalciuria RR 0.25, 95% CI 0.02 to 3.97; very low-certainty evidence), preterm birth (RR 1.04, 95% CI 0.68 to 1.59; low-certainty evidence), or low birthweight (RR 1.12, 95% CI 0.82 to 1.51; low-certainty evidence).

AUTHORS' CONCLUSIONS

This updated review using the trustworthy assessment tool removed 21 studies from the previous update and added one new study for a total of 10 included studies. In this setting, supplementation with vitamin D alone compared to no intervention or a placebo resulted in very uncertain evidence on pre-eclampsia, gestational diabetes, preterm birth, or nephritic syndrome. It may reduce the risk of severe postpartum haemorrhage; however, only one study reported this outcome. It may also reduce the risk of low birthweight; however, the upper CI suggests that an increase in risk cannot be ruled out. Supplementation with vitamin D and calcium versus placebo or no intervention resulted in very uncertain evidence on preterm birth and low birthweight. Pre-eclampsia, gestational diabetes, and maternal adverse events were not reported in the only study included in this comparison. Supplementation with vitamin D + calcium + other vitamins and minerals versus calcium + other vitamins and minerals (but no vitamin D) resulted in very uncertain evidence on gestational diabetes and maternal adverse events (hypercalciuria) and uncertain evidence on preterm birth and low birthweight. Pre-eclampsia was not reported in the only study included in this comparison. All findings warrant further research. Additional rigorous, high-quality, and larger randomised trials are required to evaluate the effects of vitamin D supplementation in pregnancy, particularly in relation to the risk of maternal adverse events.

Placental structural adaptation to maternal physical activity and sedentary behavior: findings of the DALI lifestyle study

STUDY QUESTION

Are maternal levels of moderate-to-vigorous physical activity (MVPA) and sedentary time (ST) in obese pregnant women associated with placental structural adaptations for facilitating oxygen delivery to the fetus?

SUMMARY ANSWER

Higher maternal MVPA and ST are associated with a higher density of villi, a proxy measure of placental surface area for oxygen delivery to the fetus, without further added placental vessels.

WHAT IS KNOWN ALREADY

Physical activity during pregnancy intermittently reduces uterine blood flow, potentially limiting placental and fetal oxygen supply. The placenta can mount several adaptive responses, including enlargement of the surface area of villi and/or feto-placental vessels to accommodate fetal needs. Early research on the morphology and growth of the placenta with exercise interventions has shown inconsistencies and is lacking, particularly in non-lean pregnant women.

STUDY DESIGN, SIZE, DURATION

This study is a secondary longitudinal analysis of the vitamin D and lifestyle intervention for gestational diabetes prevention (DALI) randomized controlled trial. The prospective study was conducted between 2012 and 2015 in nine European countries at 11 different sites. In this analysis, 92 pregnant women with a BMI ≥ 29 kg/m2 were combined into one cohort.

PARTICIPANTS/MATERIALS, SETTING, METHODS

MVPA and percentage of time spent sedentary (% ST) were measured with accelerometers during gestation. Placental sections were immunostained for endothelial cell-specific CD34. Artificial intelligence (AI)-based stereology assessed villous density, number, and cross-sectional area of vessels on whole-slide images and in selected regions comprising peripheral villi only, where the majority of vascular adaptations occur. Expression of pro- and anti-angiogenic factors was quantified using molecular counting analysis.

MAIN RESULTS AND THE ROLE OF CHANCE

In multivariable regression, higher levels of maternal MVPA (min/day) were associated with a higher density of villi in both whole-slide images (beta 0.12; 95% CI 0.05, 0.2) and selected regions (0.17; CI 0.07, 0.26). Unexpectedly, ST was also positively associated with density of villi (0.23; CI 0.04, 0.43). MVPA and ST were not associated with vessel count/mm2 villous area, vessel area, or pro- and anti-angiogenic factor mRNA expression. All estimates and statistical significance of the sensitivity analyses excluding smokers, women who developed gestational diabetes or pre-eclampsia and/or pregnancy-induced hypertension were similar in the main analysis.

LIMITATIONS, REASONS FOR CAUTION

The placenta is a complex organ undergoing dynamic changes. While various adjustments were made to account for different maternal contributing factors, in addition to the outcome measures, various other factors could impact oxygen delivery to the fetus.

WIDER IMPLICATIONS OF THE FINDINGS

For the first time, we evaluated the association between placental structures quantified using an AI-based approach with objectively measured physical activity and ST at multiple time points in pregnant women with obesity. The observed adaptations contribute to the advancement of our understanding of the hemodynamics and adaptations of the placental unit in response to MVPA and ST. However, our results might not be generalizable to lean pregnant women.

STUDY FUNDING/COMPETING INTEREST(S)

The DALI project has received funding from the European Community's 7th Framework Program (FP7/2007-2013) under grant agreement no. 242187. The funders had no role in study design, collection of data, analyses, writing of the article, or the decision to submit it for publication. The authors have no conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

ISRCTN70595832.

Gremlin-1 in pregnancy and postpartum: relation to the fatty liver index, markers of bone health, glucose metabolism and gestational diabetes mellitus status

INTRODUCTION

Gremlin-1 is a peptide that functions as an antagonist to bone morphogenic proteins and is overexpressed in obesity and type 2 diabetes mellitus. Gremlin-1 has not yet been investigated in pregnancy, pregnancy-related insulin resistance or gestational diabetes mellitus (GDM).

PATIENTS AND METHODS

Gremlin-1 levels were measured throughout the pregnancy of 58 women at high risk for GDM at the Medical University of Vienna. Furthermore, an oral glucose tolerance test, fasting insulin, fasting glucose, sex hormones, blood lipids, liver and renal parameters, and markers of bone development were evaluated at two points during pregnancy (< 20 weeks of gestation (GW), GW 24-28) and 12-14 weeks postpartum.

RESULTS

Gremlin-1 levels decreased from < 20 GW (mean = 9.2 pg/ml, SD = 8.4 pg/ml) to GW 24-28 (mean = 6.7 pg/ml, SD = 5.7 pg/ml, p = 0.033) and increased again postpartum, albeit not significantly (mean = 10.7 pg/ml, SD = 13.1 pg/ml, p = 0.339). During pregnancy, Gremlin-1 levels correlated negatively with osteocalcin and procollagen type I aminoterminal propeptide (P1NP), markers of bone health. Concerning glucose metabolism, Gremlin-1 levels were inversely related to the Insulinogenic Index at GW < 20. However, Gremlin-1 levels were not significantly different between women with normal glucose tolerance and GDM during pregnancy. Postpartum, Gremlin-1 was associated with the fatty liver index, osteocalcin levels, diastolic blood pressure and weight.

CONCLUSION

Gremlin-1 levels decreased significantly during pregnancy. The biomarker is not related to GDM status, but correlates negatively with the Insulinogenic Index, an index related to beta cell function. Trial Registry Number ACTRN12616000924459.

Physical activity and sedentary time across pregnancy and associations with neonatal weight, adiposity and cord blood parameters: a secondary analysis of the DALI study

BACKGROUND/OBJECTIVES

Obesity during pregnancy is associated with neonatal adiposity, which is a risk factor for childhood obesity. Maternal physical activity (PA) and sedentary behaviours during pregnancy might modify this risk. We therefore studied associations between maternal PA and sedentary time (ST) during pregnancy and neonatal anthropometry and cord blood parameters and investigated whether associations differed by offspring sex.

SUBJECTS/METHODS

Participants of the Vitamin D And Lifestyle Intervention for Gestational Diabetes Mellitus Prevention (DALI) study with a BMI  ≥ 29 kg/m2 were analysed as a cohort. Maternal moderate-to-vigorous PA (MVPA) and ST were measured repeatedly with accelerometers across pregnancy. Associations between mean levels and changes in MVPA and ST and birthweight, neonatal adiposity (fat mass (FM)%) and cord blood parameters, including C-peptide, leptin and lipids, were analysed in 213 mother-child pairs with Bayesian multilevel models. Interactions with offspring sex were considered.

RESULTS

Almost all women decreased MVPA levels and increased ST throughout gestation. Both higher maternal mean MVPA and increasing MVPA were associated with lower offspring FM% in males (-0.520%; 95% CI: -1.011%, -0.031% and -4.649%; -7.876%, -1.432% respectively). In female offspring, mean ST was associated with lower cord blood C-peptide (-0.145 µg/l; -0.279 µg/l, -0.005 µg/l). No associations were found with birthweight or other cord blood parameters.

CONCLUSIONS

Maternal MVPA is associated with neonatal fat mass, but not birthweight, in male offspring. Our findings underline the importance of physical activity throughout pregnancy.

Effect of vitamin D supplementation on glucose control in mid-late gestation: A randomized controlled trial

BACKGROUND & AIMS

It is unclear whether vitamin D supplementation contributes to gestational glucose control and whether the specific effects vary in individuals with diverse genetic and metabolic contexts. The study aimed to assess the effect of vitamin D supplementation during pregnancy on subsequent glucose levels and to identify factors modulating the response to vitamin D3 intake.

METHODS

We conducted a multicenter randomized controlled trial, 1720 pregnant women recruited from the three antenatal clinics of Hefei city, China, who were allocated to receive either 1600 IU/d vitamin D3 (n = 858) or 400 IU/d vitamin D3 (n = 862) for 2 months at 24-28 weeks' gestation. Outcomes were changes in serum 25-hydroxyvitamin D (25(OH)D) and fasting plasma glucose (FPG) levels from baseline, 32-36 weeks' gestation to delivery (37-41 weeks) quantified using a linear mixed model.

RESULTS

After 2 months, FPG levels of the control group significantly increased by 0.22 mmol/L (from 4.6 [0.4] mmol/L to 4.8 [1.2] mmol/L, P < 0.001) at delivery, but that of the intervention group had no significant variation (from 4.6 [0.4] mmol/L to 4.7 [1.1] mmol/L; between-group difference in changes, -0.2 mmol/L, 95% CI, -0.3 to -0.08, P = 0.015). And differences in FPG variation were found in participants with the ApaI SNP CC genotype, or BsmI-CC, TaqI-AA, FokI-AA, respectively. Pregnant women with basal 25(OH)D concentrations higher than 50 nmol/L subgroup showed the greatest decline in FPG levels (between-group difference, -0.3 mmol/L; 95% CI, -0.5 to -0.1, P < 0.001). Moreover, pregnant women with GDM, multiple pregnancies or who were overweight were more likely to have FPG decline from vitamin D treatment.

CONCLUSIONS

Vitamin D supplementation significantly protected glucose homeostasis in mid-late gestation, and glycemic response to vitamin D may be dependent on basal 25(OH)D status, VDR gene polymorphism or their metabolic profiles.

TRIAL REGISTRATION NUMBER

ChiCTR2100051914. URL OF REGISTRATION: http://www.chictr.org.cn/showproj.aspx?proj=134700.

The Association of Physical Activity and Sedentary Behavior with Maternal and Cord Blood Anti-Oxidative Capacity and HDL Functionality: Findings of DALI Study

Obesity is one of the most common health issues in pregnancy with short and long-term consequences for both mother and her offspring. Promoting moderate to vigorous physical activity (MVPA) and decreasing sedentary time (ST) could have a positive impact on weight and obesity management, and therefore adiposity-induced oxidative stress, inflammation, and atherogenesis. However, the effects of MVPA and ST on anti-oxidative and anti-atherogenic markers in pregnancy have not been studied to date. This study aimed to assess the association of longitudinally and objectively measured MVPA and ST in 122 overweight/obese women (BMI ≥ 29 kg/m2) with maternal and cord blood markers of oxidative stress measured by advanced oxidation protein products (AOPP), anti-oxidative capacity, as well as high-density lipoproteins (HDL) related paraoxonase-1 (PON-1) activity and cholesterol efflux. Linear regression models showed no associations of MVPA and ST with outcomes in maternal blood. In contrast, MVPA at <20 weeks and 24–28 weeks of gestation were positively associated with anti-oxidative capacity, as well as PON-1 activity of HDL in cord blood. MVPA at 35–37 weeks correlated with higher AOPP, as well as higher anti-oxidative capacity. ST <20 weeks was also positively associated with inhibition of oxidation in cord blood. We speculate that increasing MVPA of overweight/obese women during pregnancy attenuates the oxidative stress state in the new-born.

Obesity Affects Maternal and Neonatal HDL Metabolism and Function

Pregravid obesity is one of the major risk factors for pregnancy complications such as gestational diabetes mellitus (GDM) and an increased risk of cardiovascular events in children of affected mothers. However, the biological mechanisms that underpin these adverse outcomes are not well understood. High-density lipoproteins (HDLs) are antiatherogenic by promoting the efflux of cholesterol from macrophages and by suppression of inflammation. Functional impairment of HDLs in obese and GDM-complicated pregnancies may have long-term effects on maternal and offspring health. In the present study, we assessed metrics of HDL function in sera of pregnant women with overweight/obesity of the DALI lifestyle trial (prepregnancy BMI ≥ 29 kg/m2) and women with normal weight (prepregnancy BMI < 25 kg/m2), as well as HDL functionalities in cord blood at delivery. We observed that pregravid obesity was associated with impaired serum antioxidative capacity and lecithin−cholesterol acyltransferase activity in both mothers and offspring, whereas maternal HDL cholesterol efflux capacity was increased. Interestingly, functionalities of maternal and fetal HDL correlated robustly. GDM did not significantly further alter the parameters of HDL function and metabolism in women with obesity, so obesity itself appears to have a major impact on HDL functionality in mothers and their offspring.

Gestational Hypertension and High-Density Lipoprotein Function: An Explorative Study in Overweight/Obese Women of the DALI Cohort

Gestational hypertension (GHTN) is associated with an increased cardiovascular risk for mothers and their offspring later in life. High-density lipoproteins (HDL) are anti-atherogenic by promoting efflux of cholesterol from macrophages and suppression of endothelial cell activation. Functional impairment of HDL in GHTN-complicated pregnancies may affect long-term health of both mothers and offspring. We studied functional parameters of maternal and neonatal HDL in 192 obese women (pre-pregnancy BMI ≥ 29), who were at high risk for GHTN. Maternal blood samples were collected longitudinally at <20 weeks, at 24−28 and 35−37 weeks of gestation. Venous cord blood was collected immediately after birth. Maternal and cord blood were used to determine functional parameters of HDL, such as HDL cholesterol efflux capacity, activity of the vaso-protective HDL-associated enzyme paraoxonase-1, and levels of the HDL-associated anti-inflammatory apolipoprotein (apo)M. In addition, we determined serum anti-oxidative capacity. Thirteen percent of the women were diagnosed with GHTN. While we found no changes in measures of HDL function in mothers with GHTN, we observed impaired HDL cholesterol efflux capacity and paraoxonase-1 activity in cord blood, while serum antioxidant capacity was increased. Of particular interest, increased maternal paraoxonase-1 activity and apoM levels in early pregnancy were associated with the risk of developing GHTN. GHTN significantly impairs HDL cholesterol efflux capacity as well as HDL PON1 activity in cord blood and could affect vascular health in offspring. Maternal paraoxonase-1 activity and apoM levels in early pregnancy associate with the risk of developing GHTN.

The Role of Early Pregnancy Maternal pGCD59 Levels in Predicting Neonatal Hypoglycemia-Subanalysis of the DALI Study

CONTEXT

Neonatal hypoglycaemia (NH) is the most common metabolic problem in infants born of mothers with gestational diabetes. Plasma glycated CD59 (pGCD59) is an emerging biomarker that has shown potential in identifying women at risk of developing gestational diabetes. The aim of this study was to assess the association between early maternal levels of pGCD59 and NH.

OBJECTIVE

The aim of this study was to assess the association between early pregnancy maternal levels of plasma glycated CD59 (pGCD59) and neonatal hypoglycemia (NH).

METHODS

This is an observational study of pregnant women with a prepregnancy body mass index (BMI) greater than or equal to 29 screened for eligibility to participate in the Vitamin D and Lifestyle Intervention for Gestational Diabetes (DALI) trial. This analysis included 399 pregnancies. Levels of pGCD59 were measured in fasting maternal samples taken at the time of a 75-g, 2-hour oral glucose tolerance test performed in early pregnancy (< 20 weeks). NH, the study outcome, was defined as a heel-prick capillary glucose level of less than 2.6 mmol/L within 48 hours of delivery.

RESULTS

We identified 30 infants with NH. Maternal levels of pGCD59 in early pregnancy were positively associated with the prevalence of NH (one-way analysis of variance, P < .001). The odds of NH were higher in infants from mothers in tertile 3 of pGCD59 levels compared to those from mothers in tertile 1 (odds ratio [OR]: 2.41; 95% CI, 1.03-5.63). However, this was attenuated when adjusted for maternal BMI (OR: 2.28; 95% CI, 0.96-5.43). The cross-validated area under the curve (AUC) was 0.64 (95% CI, 0.54-0.74), and adjusted for maternal BMI, age, and ethnicity, the AUC was 0.70 (95% CI, 0.56-0.78).

CONCLUSION

Although pGCD59 levels in early pregnancy in women with BMI greater than or equal to 29 are associated with NH, our results indicate that this biomarker by itself is only a fair predictor of NH.

Vitamin D3 Supplementation in Overweight/Obese Pregnant Women: No Effects on the Maternal or Fetal Lipid Profile and Body Fat Distribution-A Secondary Analysis of the Multicentric, Randomized, Controlled Vitamin D and Lifestyle for Gestational Diabetes Prevention Trial (DALI)

Vitamin D deficiency is a common finding in overweight/obese pregnant women and is associated with increased risk for adverse pregnancy outcome. Both maternal vitamin D deficiency and maternal obesity contribute to metabolic derangements in pregnancy. We aimed to assess the effects of vitamin D3 supplementation in pregnancy versus placebo on maternal and fetal lipids. Main inclusion criteria were: women <20 weeks’ gestation, BMI ≥ 29 kg/m2. Eligible women (n = 154) were randomized to receive vitamin D3 (1600 IU/day) or placebo. Assessments were performed <20, 24−28 and 35−37 weeks and at birth. Linear regression models were used to assess effects of vitamin D on maternal and cord blood lipids. In the vitamin D group significantly higher total 25-OHD and 25-OHD3 levels were found in maternal and cord blood compared with placebo. Adjusted regression models did not reveal any differences in triglycerides, LDL-C, HDL-C, free fatty acids, ketone bodies or leptin between groups. Neonatal sum of skinfolds was comparable between the two groups, but correlated positively with cord blood 25-OH-D3 (r = 0.34, p = 0.012). Vitamin D supplementation in pregnancy increases maternal and cord blood vitamin D significantly resulting in high rates of vitamin D sufficiency. Maternal and cord blood lipid parameters were unaffected by Vitamin D3 supplementation.

The Weak Relationship between Vitamin D Compounds and Glucose Homeostasis Measures in Pregnant Women with Obesity: An Exploratory Sub-Analysis of the DALI Study

Studies on the relationship between vitamin D (VitD) and glucose homeostasis usually consider either total VitD or 25OHD3 but not 25OHD2 and epimers. We aimed to evaluate the cross-sectional association of VitD compounds with glucose homeostasis measurements in pregnant women with overweight/obesity participating in the Vitamin D And Lifestyle Intervention for Gestational Diabetes Mellitus Prevention study. Methods: The analysis included 912 women. Inclusion criteria: <20 weeks gestation, body mass index ≥29 kg/m2 and information on exposure and outcome variables at baseline. Measurements: A 75 g OGTT at <20, 24−28 and 35−37 weeks gestation (except if previous diabetes diagnosis). Exposure variables: 25OHD2, 25OHD3 and C3-epimer. Outcome variables: fasting and post-challenge insulin sensitivity and secretion indices, corresponding disposition indices (DI), plasma glucose at fasting and 1 and 2 h, hyperglycemia in pregnancy (HiP). Statistics: Multivariate regression analyses with adjustment. Results: Baseline VitD sufficiency was 66.3%. Overall, VitD compounds did not show strong associations with any glucose homeostasis measures. 25OHD3 showed direct significant associations with: FPG at <20 and 24−28 weeks (standardized β coefficient (β) 0.124, p = 0.030 and 0.111, p = 0.026 respectively), 2 h plasma glucose at 24−28 weeks (β 0.120, p = 0.018), and insulin sensitivity (1/HOMA-IR, β 0.127, p = 0.027) at 35−37 weeks; it showed an inverse association with fasting DI (QUCKI*HOMA-β) at <20 and 24−28 weeks (β −0.124, p = 0.045 and β −0.148, p = 0.004 respectively). 25OHD2 showed direct associations with post-challenge insulin sensitivity (Matsuda, β 0.149, p = 0.048) at 24−28 weeks) and post-challenge DI (Matsuda*Stumvoll phase 1) at 24−28 and 35−37 weeks (β 0.168, p = 0.030, β 0.239, p = 0.006). No significant association with C3-epimer was observed at any time period. Conclusions: In these women with average baseline VitD in sufficiency range, VitD compounds did not show clear beneficial associations with glucose homeostasis measures.

Plasma-glycated CD59 as an early biomarker for gestational diabetes mellitus: prospective cohort study protocol

INTRODUCTION

The significant maternal and neonatal outcomes of gestational diabetes mellitus (GDM) make it a major public health concern. Mothers with GDM are at greater risk of pregnancy complications and their offspring are at higher risk of diabetes and obesity. Currently, GDM is diagnosed with glucose load methods which are time-consuming and inconvenient to administer more than once during pregnancy; for this reason, there is a recognised need for a more accurate and simpler test for GDM. Previous studies indicate that plasma-glycated CD59 (pGCD59) is a novel biomarker for GDM. We present here the protocol of a prospective cohort study designed to (1) determine the accuracy of pGCD59 as an early, first trimester predictor of GDM and gestational impaired glucose tolerance and (2) assess the associations between pGCD59 levels and adverse maternal and neonatal outcomes.

METHODS AND ANALYSIS

We will obtain discarded plasma samples from pregnant women at two time points: first prenatal visit (usually <14 weeks gestation) and gestational weeks 24-28. A study-specific medical record abstraction tool will be used to obtain relevant maternal and neonatal clinical data from the EPIC clinical database. The prevalence of GDM will be determined using standard of care glucose load test results. We will determine the sensitivity and specificity of pGCD59 to predict the diagnosis of GDM and gestational impaired glucose tolerance, as well as the associations between levels of pGCD59 and the prevalence of maternal and neonatal outcomes.

ETHICS AND DISSEMINATION

This study has been approved by the Mass General Brigham Institutional Review Board (protocol 2011P002254). The results of this study will be presented at international meetings and disseminated in peer-reviewed journals.

The unexplored role of sedentary time and physical activity in glucose and lipid metabolism-related placental mRNAs in pregnant women who are obese: the DALI lifestyle randomised controlled trial

OBJECTIVE

We aimed to explore: (i) the association of sedentary time (ST) and physical activity (PA) during pregnancy with the placental expression of genes related to glucose and lipid metabolism in pregnant women who are obese; (ii) maternal metabolic factors mediating changes in these placental transcripts; and (iii) cord blood markers related to the mRNAs mediating neonatal adiposity.

DESIGN

Multicentre randomised controlled trial.

SETTING

Hospitals in nine European countries.

POPULATION

A cohort of 112 pregnant women with placental tissue.

METHODS

Both ST and moderate-to-vigorous PA (MVPA) levels were measured objectively using accelerometry at three time periods during pregnancy.

MAIN OUTCOME MEASURES

Placental mRNAs (FATP2, FATP3, FABP4, GLUT1 and PPAR-γ) were measured with NanoString technology. Maternal and fetal metabolic markers and neonatal adiposity were assessed.

RESULTS

Longer periods of ST, especially in early to middle pregnancy, was associated with lower placental FATP2 and FATP3 expression (P < 0.05), whereas MVPA at baseline was inversely associated with GLUT1 mRNA (P = 0.02). Although placental FATP2 and FATP3 expression were regulated by the insulin-glucose axis (P < 0.05), no maternal metabolic marker mediated the association of ST/MVPA with placental mRNAs (P > 0.05). Additionally, placental FATP2 expression was inversely associated with cord blood triglycerides and free fatty acids (FFAs; P < 0.01). No cord blood marker mediated neonatal adiposity except for cord blood leptin, which mediated the effects of PPAR-γ on neonatal sum of skinfolds (P < 0.05).

CONCLUSIONS

In early to middle pregnancy, ST is associated with the expression of placental genes linked to lipid transport. PA is hardly related to transporter mRNAs. Strategies aimed at reducing sedentary behaviour during pregnancy could modulate placental gene expression, which may help to prevent unfavourable fetal and maternal pregnancy outcomes.

TWEETABLE ABSTRACT

Reducing sedentary behaviour in pregnancy might modulate placental expression of genes related to lipid metabolism in women who are obese.

The Temporal Profile of Circulating miRNAs during Gestation in Overweight and Obese Women with or without Gestational Diabetes Mellitus

Circulating non-coding microRNAs (miRNAs) are important for placentation, but their expression profiles across gestation in pregnancies, which are complicated by gestational diabetes mellitus (GDM), have not been fully established. Investigating a single time point is insufficient, as pregnancy is dynamic, involving several processes, including placenta development, trophoblast proliferation and differentiation and oxygen sensing. Thus, the aim of this study was to compare the temporal expression of serum miRNAs in pregnant women with and without GDM. This is a nested case-control study of longitudinal data obtained from a multicentric European study (the ‘DALI’ study). All women (n = 82) were overweight/obese (BMI ≥ 29 kg/m²) and were normal glucose tolerant (NGT) at baseline (before 20 weeks of gestation). We selected women (n = 41) who were diagnosed with GDM at 24–28 weeks, according to the IADPSG/WHO2013 criteria. They were matched with 41 women who remained NGT in their pregnancy. miRNA (miR-16-5p, -29a-3p, -103-3p, -134-5p, -122-5p, -223-3p, -330-3p and miR-433-3p) were selected based on their suggested importance for placentation, and measurements were performed at baseline and at 24–28 and 35–37 weeks of gestation. Women with GDM presented with overall miRNA levels above those observed for women remaining NGT. In both groups, levels of miR-29a-3p and miR-134-5p increased consistently with progressing gestation. The change over time only differed for miR-29a-3p when comparing women with GDM with those remaining NGT (p = 0.044). Our findings indicate that among overweight/obese women who later develop GDM, miRNA levels are already elevated early in pregnancy and remain above those of women who remain NGT during their pregnancy. Maternal circulating miRNAs may provide further insight into placentation and the cross talk between the maternal and fetal compartments.

Interaction between rs10830962 polymorphism in MTNR1B and lifestyle intervention on maternal and neonatal outcomes: secondary analyses of the DALI lifestyle randomized controlled trial

BACKGROUND

Interactions between polymorphisms of the melatonin receptor 1B (MTNR1B) gene and lifestyle intervention for gestational diabetes have been described. Whether these are specific for physical activity or the healthy eating intervention is unknown.

OBJECTIVES

The aim was to assess the interaction between MTNR1B rs10830962 and rs10830963 polymorphisms and lifestyle interventions during pregnancy.

METHODS

Women with a BMI (in kg/m2) of ≥29 (n = 436) received counseling on healthy eating (HE), physical activity (PA), or both. The control group received usual care. This secondary analysis had a factorial design with comparison of HE compared with no HE and PA compared with no PA. Maternal outcomes at 24-28 wk were gestational weight gain (GWG), maternal fasting glucose, insulin, insulin resistance (HOMA-IR), disposition index, and development of GDM. Neonatal outcomes were cord blood leptin and C-peptide and estimated neonatal fat percentage. The interaction between receiving either the HE or PA intervention and genotypes of both rs10830962 and rs10830963 was assessed using multilevel regression analysis.

RESULTS

GDM risk was increased in women homozygous for the G allele of rs10830962 (OR: 2.60; 95% CI: 1.34, 5.06) or rs10830963 (OR: 2.83; 95% CI: 1.24, 6.47). Significant interactions between rs10830962 and interventions were found: in women homozygous for the G allele but not in the other genotypes, the PA intervention reduced maternal fasting insulin (β: -0.16; 95% CI: -0.33, 0.02; P = 0.08) and HOMA-IR (β: -0.17; 95% CI: -0.35, 0.01; P = 0.06), and reduced cord blood leptin (β: -0.84; 95% CI: -1.42, -0.25; P = 0.01) and C-peptide (β: -0.62; 95% CI: -1.07, -0.17; P = 0.01). In heterozygous women, the HE intervention had no effect, whereas in women homozygous for the C allele, HE intervention reduced GWG (β: -1.6 kg; 95% CI: -2.4, -0.8 kg). No interactions were found.

CONCLUSIONS

In women homozygous for the risk allele of MTNR1B rs10830962, GDM risk was increased and PA intervention might be more beneficial than HE intervention for reducing maternal insulin resistance, cord blood C-peptide, and cord blood leptin.

Glypican-4 in pregnancy and its relation to glucose metabolism, insulin resistance and gestational diabetes mellitus status

Glypican-4 (GPC-4) is an adipokine that enhances insulin receptor signaling. Plasma concentrations were found to be elevated in patients with prediabetes but reduced in type 2 diabetes mellitus. No study on Glypican-4 in pregnancy and pregnancy-related insulin resistance has been published yet. GPC-4 levels were investigated in 59 overweight women throughout their pregnancy at the Medical University of Vienna. GPC-4 levels, fasting insulin, fasting glucose, estradiol, liver and renal parameters, and markers of bone development were assessed before the < 21st week of gestation (GW), and at GW 35-37. GPC-4 levels increased from < 21 GW (mean = 2.38 pg/ml, SD = 0.68 pg/ml) to GW 35-37 (mean = 2.96 pg/ml, SD = 0.77 pg/ml, p < 0.001). At the same time, GPC-4 levels correlated negatively with estimated glomerular filtration rate (eGFR), serum protein and serum albumin levels and were positively related to creatinine and uric acid levels at GW 35-37. Concerning glucose metabolism, GPC-4 levels were inversely related to ISSI-2, fasting insulin and HOMA-IR, however, not significantly different between women with normal glucose tolerance (NGT) and GDM (p = 0.239). In conclusion, GPC-4 levels rose significantly during pregnancy, correlated negatively with fasting insulin and HOMA-IR but might not be related to gestational diabetes mellitus status.

Do Lifestyle Interventions in Pregnant Women with Overweight or Obesity Have an Effect on Neonatal Adiposity? A Systematic Review with Meta-Analysis

Excessive body fat at birth is a risk factor for the development of childhood obesity. The aim of the present systematic review with meta-analysis was to evaluate the effect of lifestyle interventions in pregnant women with overweight or obesity on neonatal adiposity. The PubMed, Embase, Web of Science, Scopus, and LILACS databases were used as information sources. Original articles from randomized clinical trials of lifestyle intervention studies on pregnant women with excessive body weight and the effect on neonatal adiposity were considered eligible. The risk of bias was assessed using Cochrane criteria. The meta-analysis was calculated using the inverse variance for continuous data expressed as mean difference (MD), using the random effect model with a 95% confidence interval (CI). The outcomes were submitted to the GRADE evaluation. Of 2877 studies, four were included in the qualitative and quantitative synthesis (n = 1494). All studies were conducted in developed countries, with three including pregnant women with overweight or obesity, and one only pregnant women with obesity. The interventions had no effect on neonatal adiposity [Heterogeneity = 56%, MD = −0.21, CI = (−0.92, 0.50)] with low confidence in the evidence, according to GRADE. Studies are needed in low- and medium-developed countries with different ethnic-racial populations. PROSPERO (CRD42020152489).

Atlantic DIP: is weight gain less than that recommended by IOM safe in obese women with gestational diabetes mellitus?

BACKGROUND/OBJECTIVES

The Institute of Medicine (IOM) recommends gestational weight gain (GWG) of 5-9 kg in women with a body mass index (BMI) ≥ 30 kg/m². Debate continues as to whether GWG less than that recommended is safe in women with gestational diabetes mellitus (GDM). The study objective was to examine maternal and infant outcomes for obese women with GDM who lost weight or gained 0-5 kg during pregnancy.

SUBJECTS/METHODS

A 7-year retrospective cohort study of pregnancy outcomes for obese women with GDM recorded in the Atlantic Diabetes in Pregnancy database was conducted. We examined pregnancy outcomes for mothers with GDM and a BMI ≥ 30 who either lost weight or gained 0-5 kg (Group 1, n = 237) and women who gained 5-9 kg (Group 2, n = 77). We further divided groups 1 and 2 into women treated by diet only (GDM-D) (n = 120) and those requiring additional treatment with insulin (GDM-I) (n = 194).

RESULTS

GDM-D women in Group 1 were more likely to deliver earlier (38.9 vs 39.8 weeks, p < 0.01), to develop pregnancy induced hypertension (PIH) (15.4% v 0%; p = 0.02) or have a post-partum haemorrhage (PPH) (13.2% vs 0, p = 0.03) compared to women in Group 2. Rates of prematurity were higher in group 1 vs 2 (14.3% vs 0%, p = 0.03). However, further logistic regression analysis adjusted for smoking status, family history of diabetes, ethnicity and age determined no significant difference in maternal or infant outcomes for women in Group 1 compared to those in Group 2.

CONCLUSION

In our population, weight gain less than IOM guideline appears safe and is not associated with any further increase in adverse outcomes. However, validation through a prospective study with a larger obese GDM cohort is required before the findings presented here could be recommended for routine clinical use.

Core outcomes in gestational diabetes for treatment trials: The Gestational Metabolic Group treatment set

Aims

With the rising number of outcomes being reported following gestational diabetes (GDM), the outcomes in existing studies vary widely making it challenging to compare and contrast the effectiveness of different interventions for GDM. The purpose of this study was to develop a core outcome and measurement set (COS) for GDM treatment trials.

Materials & Methods

A Delphi study with structured consultation with stakeholders and discussion within a specialist Gestational Metabolic Group (GEM) were combined with a comprehensive systematic search across different databases (PubMed, Cochrane Library, and Embase). Several Delphi rounds over 2 years were conducted culminating in this report.

Results

The process resulted in a targeted set of outcomes constituting a “GEM treatment set” aligned with expert opinion. The final COS also included a measurement set for the 11 important clinical outcomes from three major domains: maternal metabolic, fetal, and pregnancy related.

Conclusions

Based on the results of this study, it is recommended that future clinical trials on GDM report outcomes uniformly keeping to the recommended COS outcomes.

Metabolic phenotypes of early gestational diabetes mellitus and their association with adverse pregnancy outcomes

AIMS

To describe the metabolic phenotypes of early gestational diabetes mellitus and their association with adverse pregnancy outcomes.

METHODS

We performed a post hoc analysis using data from the Vitamin D And Lifestyle Intervention for gestational diabetes prevention (DALI) trial conducted across nine European countries (2012-2014). In women with a BMI ≥29 kg/m² , insulin resistance and secretion were estimated from the oral glucose tolerance test values performed before 20 weeks, using homeostatic model assessment of insulin resistance and Stumvoll first-phase indices, respectively. Women with early gestational diabetes, defined by the International Association of Diabetes and Pregnancy Study Groups criteria, were classified into three groups: GDM-R (above-median insulin resistance alone), GDM-S (below-median insulin secretion alone), and GDM-B (combination of both) and the few remaining women were excluded.

RESULTS

Compared with women in the normal glucose tolerance group (n = 651), women in the GDM-R group (n = 143) had higher fasting and post-load glucose values and insulin levels, with a greater risk of having large-for-gestational age babies [adjusted odds ratio 3.30 (95% CI 1.50-7.50)] and caesarean section [adjusted odds ratio 2.30 (95% CI 1.20-4.40)]. Women in the GDM-S (n = 37) and GDM-B (n = 56) groups had comparable pregnancy outcomes with those in the normal glucose tolerance group.

CONCLUSIONS

In overweight and obese women with early gestational diabetes, higher degree of insulin resistance alone was more likely to be associated with adverse pregnancy outcomes than lower insulin secretion alone or a combination of both.

The Predictive Value of miR-16, -29a and -134 for Early Identification of Gestational Diabetes: A Nested Analysis of the DALI Cohort

Early identification of gestational diabetes mellitus (GDM) aims to reduce the risk of adverse maternal and perinatal outcomes. Currently, no circulating biomarker has proven clinically useful for accurate prediction of GDM. In this study, we tested if a panel of small non-coding circulating RNAs could improve early prediction of GDM. We performed a nested case-control study of participants from the European multicenter ‘Vitamin D and lifestyle intervention for GDM prevention (DALI)’ trial using serum samples from obese pregnant women (BMI ≥ 29 kg/m²) entailing 82 GDM cases (early- and late- GDM), and 41 age- and BMI-matched women with normal glucose tolerance (NGT) throughout pregnancy (controls). Anthropometric, clinical and biochemical characteristics were obtained at baseline (<20 weeks of gestation) and throughout gestation. Baseline serum microRNAs (miRNAs) were measured using quantitative real time PCR (qPCR). Elevated miR-16-5p, -29a-3p, and -134-5p levels were observed in women, who were NGT at baseline and later developed GDM, compared with controls who remained NGT. A combination of the three miRNAs could distinguish later GDM from NGT cases (AUC 0.717, p = 0.001, compared with fasting plasma glucose (AUC 0.687, p = 0.004)) as evaluated by area under the curves (AUCs) using Receiver Operator Characteristics (ROC) analysis. Elevated levels of individual miRNAs or a combination hereof were associated with higher odds ratios of GDM. Conclusively, circulating miRNAs early in pregnancy could serve as valuable predictive biomarkers of GDM.

The importance of maternal insulin resistance throughout pregnancy on neonatal adiposity

BACKGROUND

Although previous studies evaluated the association of maternal health parameters with neonatal adiposity, little is known regarding the complexity of the relationships among different maternal health parameters throughout pregnancy and its impact on neonatal adiposity.

OBJECTIVES

To evaluate the direct and indirect associations between maternal insulin resistance during pregnancy, in women with obesity, and neonatal adiposity. In addition, associations between maternal fasting glucose, triglycerides (TG), non-esterified fatty acids (NEFA), and neonatal adiposity were also assessed.

METHODS

This is a longitudinal, secondary analysis of the DALI study, an international project conducted in nine European countries with pregnant women with obesity. Maternal insulin resistance (HOMA-IR), fasting glucose, TG, and NEFA were measured three times during pregnancy (<20, 24-28, and 35-37 weeks of gestation). Offspring neonatal adiposity was estimated by the sum of four skinfolds. Structural equation modelling was conducted to evaluate the direct and indirect relationships among the variables of interest.

RESULTS

Data on 657 mother-infant pairs (50.7% boys) were analysed. Neonatal boys exhibited lower mean sum of skinfolds compared to girls (20.3 mm, 95% CI 19.7, 21.0 vs 21.5 mm, 95% CI 20.8, 22.2). In boys, maternal HOMA-IR at <20 weeks was directly associated with neonatal adiposity (β = 0.35 mm, 95% CI 0.01, 0.70). In girls, maternal HOMA-IR at 24-28 weeks was only indirectly associated with neonatal adiposity, which implies that this association was mediated via maternal HOMA-IR, glucose, triglycerides, and NEFA during pregnancy (β = 0.26 mm, 95% CI 0.08, 0.44).

CONCLUSIONS

The timing of the role of maternal insulin resistance on neonatal adiposity depends on fetal sex. Although the association was time-dependent, maternal insulin resistance was associated with neonatal adiposity in both sexes.

Effectiveness of real-time continuous glucose monitoring to improve glycaemic control and pregnancy outcome in patients with gestational diabetes mellitus: a study protocol for a randomised controlled trial

INTRODUCTION

Real-time continuous glucose monitoring (rt-CGM) informs users about current interstitial glucose levels and allows early detection of glycaemic excursions and timely adaptation by behavioural change or pharmacological intervention. Randomised controlled studies adequately powered to evaluate the impact of long-term application of rt-CGM systems on the reduction of adverse obstetric outcomes in women with gestational diabetes (GDM) are missing. We aim to assess differences in the proportion of large for gestational age newborns in women using rt-CGM as compared with women with self-monitored blood glucose (primary outcome). Rates of neonatal hypoglycaemia, caesarean section and shoulder dystocia are secondary outcomes. A comparison of glucose metabolism and quality of life during and after pregnancy completes the scope of this study.

METHODS AND ANALYSIS

Open-label multicentre randomised controlled trial with two parallel groups including 372 female patients with a recent diagnosis of GDM (between 24+0 until 31+6 weeks of gestation): 186 with rt-CGM (Dexcom G6) and 186 with self-monitored blood glucose (SMBG). Women with GDM will be consecutively recruited and randomised to rt-CGM or control (SMBG) group after a run-in period of 6-8 days. The third visit will be scheduled 8-10 days later and then every 2 weeks. At every visit, glucose measurements will be evaluated and all patients will be treated according to the standard care. The control group will receive a blinded CGM for 10 days between the second and third visit and between week 36+0 and 38+6. Cord blood will be sampled immediately after delivery. 48 hours after delivery neonatal biometry and maternal glycosylated haemoglobin A1c (HbA1c) will be assessed, and between weeks 8 and 16 after delivery all patients receive a re-examination of glucose metabolism including blinded CGM for 8-10 days.

ETHICS AND DISSEMINATION

This study received ethical approval from the main ethic committee in Vienna. Data will be presented at international conferences and published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT03981328; Pre-results.

Performance of early pregnancy HbA1c for predicting gestational diabetes mellitus and adverse pregnancy outcomes in obese European women

AIMS

To investigate the performance of early pregnancy HbA_1c for predicting gestational diabetes mellitus (GDM) and adverse pregnancy outcomes in obese women.

METHODS

Post hoc analysis using data from the Vitamin D And Lifestyle Intervention for GDM prevention trials conducted across 9 European countries (2012-2014). Pregnant women (BMI ≥ 29 kg/m²) underwent a baseline HbA_1c and oral glucose tolerance tests at < 20 weeks, 24-28 weeks, and 35-37 weeks. Women with GDM were referred for treatment.

RESULTS

Among the 869 women tested, the prevalence of GDM was 25.9% before 20 weeks, with a further 8.6% at 24-28 weeks. The areas under the curves for HbA_1c at the two time points were 0.55 (0.50-0.59) and 0.54 (0.47-0.61), respectively. An early HbA_1c ≥ 5.7% (39 mmol/mol) (N = 111) showed low sensitivity (18.2%) with 89.1% specificity for GDM before 20 weeks, at 24-28 weeks (sensitivity of 8.0% and specificity of 88.6% after excluding early GDM), and throughout gestation (sensitivity of 15.9% and specificity of 89.4%). The ≥ 5.7% (39 mmol/mol) threshold was significantly associated with concurrent GDM before 20 weeks (adjusted OR (aOR) 2.77(1.39-5.51)) and throughout gestation (aOR 1.72 (1.02-2.89)), but not adverse pregnancy outcomes.

CONCLUSIONS

Early pregnancy HbA_1c is of limited use for predicting either GDM or adverse outcomes in overweight/obese European women.

Secretagogin is Related to Insulin Secretion but Unrelated to Gestational Diabetes Mellitus Status in Pregnancy

Secretagogin (SCGN) is a calcium binding protein related to insulin release in the pancreas. Although SCGN is not co-released with insulin, plasma concentrations have been found to be increased in type 2 diabetes mellitus patients. Until now, no study on SCGN levels in pregnancy or patients with gestational diabetes mellitus (GDM) has been published. In 93 women of a high-risk population for GDM at the Medical University of Vienna, secretagogin levels of 45 GDM patients were compared to 48 women with a normal glucose tolerance (NGT). Glucose tolerance, insulin resistance and secretion were assessed with oral glucose tolerance tests (OGTT) between the 10th and 28th week of gestation (GW) and postpartum. In all women, however, predominantly in women with NGT, there was a significant positive correlation between SCGN levels and Stumvoll first (r_p = 0.220, p = 0.032) and second phase index (r_p = 0.224, p = 0.028). SCGN levels were not significantly different in women with NGT and GDM. However, SCGN was higher postpartum than during pregnancy (postpartum: 88.07 ± 35.63 pg/mL; pregnancy: 75.24 ± 37.90 pg/mL, p = 0.004). SCGN was directly correlated with week of gestation (r_p = 0.308; p = 0.021) and triglycerides (r_p = 0.276; p = 0.038) in women with GDM. Therefore, SCGN is related to insulin secretion and hyperinsulinemia during pregnancy; however, it does not display differences between women with NGT and GDM.

Less sedentary time is associated with a more favourable glucose-insulin axis in obese pregnant women-a secondary analysis of the DALI study

Background/objectives

Obese pregnant women are at high risk of developing gestational diabetes mellitus (GDM), which might be reduced by sufficient physical activity (PA) and reduced sedentary time (ST). We assessed whether PA and ST are longitudinally associated with the glucose-insulin axis in obese pregnant women.

Subjects/methods

In this secondary analysis of the DALI (vitamin D And Lifestyle Intervention for gestational diabetes mellitus prevention) study, pregnant women, <20 weeks gestation, with a pre-pregnancy body mass index (BMI) ≥ 29 kg/m², without GDM on entry were included. Time spent in moderate-to-vigorous PA (MVPA) and ST were measured objectively with accelerometers at <20 weeks, 24–28 weeks and 35–37 weeks of gestation. Fasting glucose (mmol/l) and insulin (mU/l), insulin resistance (HOMA-IR) and first-phase and second-phase insulin release (Stumvoll first and second phase) were assessed at the same time. Linear mixed regression models were used to calculate between-participant differences and within-participant changes over time. Analyses were adjusted for gestational age, randomisation, pre-pregnancy BMI, education and age. MVPA, Insulin, HOMA-IR and Stumvoll first and second phase were log-transformed for analyses due to skewness.

Results

232 women were included in the analysis. Concerning differences between participants, more ST was associated with higher fasting glucose (Estimate: 0.008; 95% CI: 0.002, 0.014), fasting insulin (0.011; 0.002, 0.019), HOMA-IR (0.012; 0.004, 0.021) and Stumvoll first and second phase (0.008; 0.001, 0.014 and 0.007; 0.001, 0.014). Participants with more MVPA had lower Stumvoll first and second phase (−0.137; −0.210, −0.064 and −0.133; −0.202, −0.063). Concerning changes over time, an increase in ST during gestation was associated with elevated Stumvoll first and second phase (0.006; 0.000, 0.011).

Conclusions

As the glucose-insulin axis is more strongly associated with ST than MVPA in our obese population, pregnant women could be advised to reduce ST in addition to increasing MVPA. Moreover, our findings suggest that behaviour change interventions aiming at GDM risk reduction should start in early or pre-pregnancy.

Temporal relationships between maternal metabolic parameters with neonatal adiposity in women with obesity differ by neonatal sex: Secondary analysis of the DALI study

OBJECTIVES

To investigate the importance of time in pregnancy and neonatal sex on the association between maternal metabolic parameters and neonatal sum of skinfolds.

METHODS

This was a longitudinal, secondary analysis of the vitamin D and lifestyle intervention for gestational diabetes mellitus study, conducted in nine European countries during 2012 to 2015. Pregnant women with a pre-pregnancy body mass index (BMI) of ≥29 kg/m² were invited to participate. We measured 14 maternal metabolic parameters at three times during pregnancy: <20 weeks, 24 to 28 weeks, and 35 to 37 weeks of gestation. The sum of four skinfolds assessed within 2 days after birth was the measure of neonatal adiposity.

RESULTS

In total, 458 mother-infant pairs (50.2% female infants) were included. Insulin resistance (fasting insulin and HOMA-index of insulin resistance) in early pregnancy was an important predictor for boys' sum of skinfolds, in addition to fasting glucose and maternal adiposity (leptin, BMI and neck circumference) throughout pregnancy. In girls, maternal lipids (triglycerides and fatty acids) in the first half of pregnancy were important predictors of sum of skinfolds, as well as fasting glucose in the second half of pregnancy.

CONCLUSIONS

Associations between maternal metabolic parameters and neonatal adiposity vary between different periods during pregnancy. This time-dependency is different between sexes, suggesting different growth strategies.

Effects of treatment with metformin and/or sitagliptin on beta-cell function and insulin resistance in prediabetic women with previous gestational diabetes

AIM

To investigate the effect of sitagliptin (SITA) and metformin (MET) monotherapy as well as in combination (MET+SITA) on beta-cell function and insulin sensitivity in women with recent gestational diabetes (GDM) and impaired glucose regulation (IGR: impaired fasting glucose and/or impaired glucose tolerance).

MATERIAL AND METHODS

Forty women were randomly assigned to receive SITA (100 mg qd), MET (850 mg bid) or MET+SITA (50 + 850 mg bid) for 16 weeks. A 75 g oral glucose tolerance test (OGTT) and +125 mg/dL hyperglycaemic clamp followed by 5 g i.v. L-arginine were performed at baseline and end of study. The primary outcome of the study was the mean change in arginine-stimulated insulin secretion rate during the hyperglycaemic clamp test from baseline to 16-week therapy.

RESULTS

At week 16, body mass index declined in all groups (-1.2 ± 0.2 kg/m² ; P < 0.05). MET+SITA gave a greater increase of first phase_{(2-10 min)} insulin secretion and arginine-stimulated response (720.3 ± 299.0 to 995.5 ± 370.3 pmol/L and 3.2 ± 0.6 to 4.8 ± 1.0 pmoL/min, respectively, both P < 0.05) compared with MET and SITA. Similarly, MET+SITA was more effective in increasing OGTT-based glucose sensitivity (55.7 ± 11.3 to 108 ± 56.2 pmol x min^-1 m^-2 x mM^-1 ; P = 0.04) and insulin-stimulated glucose disposal (M/I: 2.2 ± 0.5 to 4.6 ± 1.3 mg/kg/min÷μIU/min/ml; P = 0.04; Matsuda index [SI]: 3.1 ± 0.4 to 5.7 ± 1.1; P = 0.03) compared with either MET or SITA. Disposition index (ISSI-2) increased with MET+SITA and SITA (both P < 0.05), while no significant change was observed in MET. Among MET+SITA women, 33% reverted to normal glucose tolerance (NGT) compared with 14% with MET and 7% with SITA (P < 0.05).

CONCLUSION

This study shows that MET+SITA is superior to SITA and MET monotherapy regarding beta-cell function and insulin sensitivity improvement in IGR women with previous GDM, and may offer a potential pharmacologic intervention to reduce the risk of type 2 diabetes in this high-risk population.

Plasma Glycated CD59 Predicts Early Gestational Diabetes and Large for Gestational Age Newborns

CONTEXT

Gestational diabetes mellitus (GDM) diagnosed in early pregnancy is a health care challenge because it increases the risk of adverse outcomes. Plasma-glycated CD59 (pGCD59) is an emerging biomarker for diabetes and GDM. The aim of this study was to assess the performance of pGCD59 as a biomarker of early GDM and its association with delivering a large for gestational age (LGA) infant.

OBJECTIVES

To assess the performance of pGCD59 to identify women with GDM in early pregnancy (GDM < 20) and assess the association of pGCD59 with LGA and potentially others adverse neonatal outcomes linked to GDM.

METHODS

Blood levels of pGCD59 were measured in samples from 693 obese women (body mass index > 29) undergoing a 75-g, 2-hour oral glucose tolerance test (OGTT) at <20 weeks' gestation in the Vitamin D and Lifestyle Intervention study: the main analyses included 486 subjects who had normal glucose tolerance throughout the pregnancy, 207 who met criteria for GDM at <20 weeks, and 77 diagnosed with GDM at pregnancy weeks 24 through 28. Reference tests were 75-g, 2-hour OGTT adjudicated based on International Association of Diabetes and Pregnancy Study Group criteria. The index test was a pGCD59 ELISA.

RESULTS

Mean pGCD59 levels were significantly higher (P < 0.001) in women with GDM < 20 (3.9 ± 1.1 standard peptide units [SPU]) than in those without (2.7 ± 0.7 SPU). pGCD59 accurately identified GDM in early pregnancy with an area under the curve receiver operating characteristic curves of 0.86 (95% confidence interval [CI], 0.83-0.90). One-unit increase in maternal pGCD59 level was associated with 36% increased odds of delivering an LGA infant (odds ratio for LGA vs non-LGA infant: 1.4; 95% CI, 1.1-1.8; P = 0.016).

CONCLUSION

Our results indicate that pGCD59 is a simple and accurate biomarker for detection of GDM in early pregnancy and risk assessment of LGA.

Characteristics of bone turnover markers in women with gestational diabetes mellitus

BACKGROUND

Bone turnover markers (BTMs) can be applied to the assessment of bone formation and bone resorption activity. The aim of this study was to investigate the changes in BTMs in women with gestational diabetes mellitus (GDM).

METHODS

One hundred and five women with gestational diabetes mellitus defined as the GDM group and 46 healthy pregnant women with normal glucose tolerance selected as the control group were enrolled in this study. Serum samples were collected during regular obstetric examinations and the serum levels of total procollagen type 1 N-terminal propeptide (P1NP), N-terminal midfragment of osteocalcin (N-MID), and β-C-terminal telopeptide of type 1 collagen (β-CTX) were measured. An independent-sample t-test, the Mann-Whitney U test, and a Pearson correlation analysis were performed for data analyses.

RESULTS

Serum β-CTX levels in the GDM group were significantly higher than those in the control group (296.00 [235.00-369.00] pg/mL vs. 218.5 [165.25-292.50] pg/mL, p < 0.05), while P1NP and N-MID levels did not differ between the two groups. The Pearson correlation analysis revealed that β-CTX level was correlated with blood glucose level.

CONCLUSIONS

The difference in β-CTX levels indicated that bone resorption in patients with GDM diabetes was higher than that in pregnant women with normal glucose tolerance. No obvious differences in bone formation markers P1NP and N-MID were found between the two groups.

The Effects of Lifestyle and/or Vitamin D Supplementation Interventions on Pregnancy Outcomes: What Have We Learned from the DALI Studies?

PURPOSE OF REVIEW

The DALI (vitamin D and lifestyle intervention in the prevention of gestational diabetes mellitus (GDM)) study aimed to prevent GDM with lifestyle interventions or Vitamin D supplementation (1600 IU/day). This review summarizes the learnings from the DALI studies among pregnant women with a BMI ≥ 29 kg/m².

RECENT FINDINGS

Women diagnosed with GDM earlier in pregnancy had a worse metabolic profile than those diagnosed later. A combined physical activity (PA) and healthy eating (HE) lifestyle intervention improved both behaviours, limited gestational weight gain (GWG) and was cost-effective. Although GDM risk was unchanged, neonatal adiposity was reduced due to less sedentary time. Neither PA nor HE alone limited GWG or GDM risk. Fasting glucose was higher with HE only intervention, and lower with Vitamin D supplementation. Our combined intervention did not prevent GDM, but was cost-effective, limited GWG and reduced neonatal adiposity.

Vitamin D supplementation and incident preeclampsia: A systematic review and meta-analysis of randomized clinical trials

BACKGROUND

Maternal vitamin D deficiency has been associated with an increased risk for preeclampsia. Despite this, the current evidence regarding the efficacy of vitamin D supplementation in preventing preeclampsia is controversial. To assess the impact of vitamin D supplementation on the risk of preeclampsia, we performed a systematic review of the literature and a meta-analysis of the available randomized clinical trials (RCTs).

METHODS

The primary outcome was preeclampsia. Subgroup analyses were carried out considering the timing of the supplementation, type of intervention and the study design. Meta-regression analysis, including the amount of vitamin D and maternal age, were planned to explore heterogeneity (PROSPERO database registration number: CRD42019119207).

RESULTS

Data were pooled from 27 RCTs comprising 59 arms, which included overall 4777 participants, of whom 2487 were in the vitamin D-treated arm and 2290 in the control arm. Vitamin D administration in pregnancy was associated with a reduced risk of preeclampsia (odd ratio [OR] 0.37, 95% confidence interval [CI]: 0.26, 0.52; I² = 0%). If the vitamin D supplementation was started up to 20 weeks' gestation, the odds was a little lower (OR 0.35, 95% CI: 0.24, 0.50, p < 0.001). The effect was largely independent of the supplementation cessation (until delivery or not), type of intervention (vitamin D alone or in association with calcium), and study design. Increasing dose of vitamin D was associated with reduced incidence of preeclampsia (slope of log OR: -1.1, 95% CI: -1.73, -0.46; p < 0.001).

CONCLUSIONS

Results suggest that vitamin D supplementation may be useful in preventing preeclampsia. These data are especially useful for health-care providers who engage in the management of pregnant women at risk for preeclampsia. Our findings are a call for action to definitively address vitamin D supplementation as a possible intervention strategy in preventing preeclampsia in pregnancy.

Nutritional Lifestyle Intervention in Obese Pregnant Women, Including Lower Carbohydrate Intake, Is Associated With Increased Maternal Free Fatty Acids, 3-β-Hydroxybutyrate, and Fasting Glucose Concentrations: A Secondary Factorial Analysis of the European Multicenter, Randomized Controlled DALI Lifestyle Intervention Trial

OBJECTIVE

In our randomized controlled trial, we investigated the impact of healthy eating (HE) aiming for restricted gestational weight gain (GWG) and physical activity (PA) interventions on maternal and neonatal lipid metabolism.

RESEARCH DESIGN AND METHODS

Obese pregnant women (n = 436) were included before 20 weeks' gestation and underwent glucose testing (oral glucose tolerance test) and lipid profiling at baseline and 24-28 and 35-37 gestational weeks after an at least 10-h overnight fast. This secondary analysis had a factorial design with comparison of HE (n = 221) versus no HE (n = 215) and PA (n = 218) versus no PA (n = 218). Maternal changes in triglycerides (TG), LDL cholesterol, HDL cholesterol, free fatty acids (FFAs), and leptin from baseline to end of pregnancy and neonatal outcomes were analyzed using general linear models with adjustment for relevant parameters.

RESULTS

At 24-28 weeks' gestation, FFAs (mean ± SD, 0.60 ± 0.19 vs. 0.55 ± 0.17 mmol/L, P < 0.01) were increased after adjustment for FFA at baseline, maternal age, BMI at time of examination, gestational week, insulin resistance, self-reported food intake, self-reported physical activity, and maternal smoking, and GWG was lower (3.3 ± 2.6 vs. 4.3 ± 2.8 kg, P < 0.001, adjusted mean differences -1.0 [95% CI -1.5; -0.5]) in HE versus no HE. Fasting glucose levels (4.7 ± 0.4 vs. 4.6 ± 0.4 mmol/L, P < 0.05) and 3-β-hydroxybutyrate (3BHB) (0.082 ± 0.065 vs. 0.068 ± 0.067 mmol/L, P < 0.05) were higher in HE. Significant negative associations between carbohydrate intake and FFA, 3BHB, and fasting glucose at 24-28 weeks' gestation were observed. No differences between groups were found in oral glucose tolerance test or leptin or TG levels at any time. Furthermore, in PA versus no PA, no similar changes were found. In cord blood, elevated FFA levels were found in HE after full adjustment (0.34 ± 0.22 vs. 0.29 ± 0.16 mmol/L, P = 0.01).

CONCLUSIONS

HE intervention was associated with reduced GWG, higher FFAs, higher 3BHB, and higher fasting glucose at 24-28 weeks of gestation, suggesting induction of lipolysis. Increased FFA was negatively associated with carbohydrate intake and was also observed in cord blood. These findings support the hypothesis that maternal antenatal dietary restriction including carbohydrates is associated with increased FFA mobilization.

Vitamin D supplementation for women during pregnancy

BACKGROUND

Vitamin D supplementation during pregnancy may be needed to protect against adverse pregnancy outcomes. This is an update of a review that was first published in 2012 and then in 2016.

OBJECTIVES

To examine whether vitamin D supplementation alone or in combination with calcium or other vitamins and minerals given to women during pregnancy can safely improve maternal and neonatal outcomes.

SEARCH METHODS

For this update, we searched Cochrane Pregnancy and Childbirth's Trials Register (12 July 2018), contacted relevant organisations (15 May 2018), reference lists of retrieved trials and registries at clinicaltrials.gov and WHO International Clinical Trials Registry Platform (12 July 2018). Abstracts were included if they had enough information to extract the data.

SELECTION CRITERIA

Randomised and quasi-randomised trials evaluating the effect of supplementation with vitamin D alone or in combination with other micronutrients for women during pregnancy in comparison to placebo or no intervention.

DATA COLLECTION AND ANALYSIS

Two review authors independently i) assessed the eligibility of trials against the inclusion criteria, ii) extracted data from included trials, and iii) assessed the risk of bias of the included trials. The certainty of the evidence was assessed using the GRADE approach.

MAIN RESULTS

We included 30 trials (7033 women), excluded 60 trials, identified six as ongoing/unpublished trials and two trials are awaiting assessments.Supplementation with vitamin D alone versus placebo/no interventionA total of 22 trials involving 3725 pregnant women were included in this comparison; 19 trials were assessed as having low-to-moderate risk of bias for most domains and three trials were assessed as having high risk of bias for most domains. Supplementation with vitamin D alone during pregnancy probably reduces the risk of pre-eclampsia (risk ratio (RR) 0.48, 95% confidence interval (CI) 0.30 to 0.79; 4 trials, 499 women, moderate-certainty evidence) and gestational diabetes (RR 0.51, 95% CI 0.27 to 0.97; 4 trials, 446 women, moderate-certainty evidence); and probably reduces the risk of having a baby with low birthweight (less than 2500 g) (RR 0.55, 95% CI 0.35 to 0.87; 5 trials, 697 women, moderate-certainty evidence) compared to women who received placebo or no intervention. Vitamin D supplementation may make little or no difference in the risk of having a preterm birth < 37 weeks compared to no intervention or placebo (RR 0.66, 95% CI 0.34 to 1.30; 7 trials, 1640 women, low-certainty evidence). In terms of maternal adverse events, vitamin D supplementation may reduce the risk of severe postpartum haemorrhage (RR 0.68, 95% CI 0.51 to 0.91; 1 trial, 1134 women, low-certainty evidence). There were no cases of hypercalcaemia (1 trial, 1134 women, low-certainty evidence), and we are very uncertain as to whether vitamin D increases or decreases the risk of nephritic syndrome (RR 0.17, 95% CI 0.01 to 4.06; 1 trial, 135 women, very low-certainty evidence). However, given the scarcity of data in general for maternal adverse events, no firm conclusions can be drawn.Supplementation with vitamin D and calcium versus placebo/no interventionNine trials involving 1916 pregnant women were included in this comparison; three trials were assessed as having low risk of bias for allocation and blinding, four trials were assessed as having high risk of bias and two had some components having a low risk, high risk, or unclear risk. Supplementation with vitamin D and calcium during pregnancy probably reduces the risk of pre-eclampsia (RR 0.50, 95% CI 0.32 to 0.78; 4 trials, 1174 women, moderate-certainty evidence). The effect of the intervention is uncertain on gestational diabetes (RR 0.33,% CI 0.01 to 7.84; 1 trial, 54 women, very low-certainty evidence); and low birthweight (less than 2500 g) (RR 0.68, 95% CI 0.10 to 4.55; 2 trials, 110 women, very low-certainty evidence) compared to women who received placebo or no intervention. Supplementation with vitamin D and calcium during pregnancy may increase the risk of preterm birth < 37 weeks in comparison to women who received placebo or no intervention (RR 1.52, 95% CI 1.01 to 2.28; 5 trials, 942 women, low-certainty evidence). No trial in this comparison reported on maternal adverse events.Supplementation with vitamin D + calcium + other vitamins and minerals versus calcium + other vitamins and minerals (but no vitamin D)One trial in 1300 participants was included in this comparison; it was assessed as having low risk of bias. Pre-eclampsia was not assessed. Supplementation with vitamin D + other nutrients may make little or no difference in the risk of preterm birth < 37 weeks (RR 1.04, 95% CI 0.68 to 1.59; 1 trial, 1298 women, low-certainty evidence); or low birthweight (less than 2500 g) (RR 1.12, 95% CI 0.82 to 1.51; 1 trial, 1298 women, low-certainty evidence). It is unclear whether it makes any difference to the risk of gestational diabetes (RR 0.42, 95% CI 0.10 to 1.73) or maternal adverse events (hypercalcaemia no events; hypercalciuria RR 0.25, 95% CI 0.02 to 3.97; 1 trial, 1298 women,) because the certainty of the evidence for both outcomes was found to be very low.

AUTHORS' CONCLUSIONS

We included 30 trials (7033 women) across three separate comparisons. Our GRADE assessments ranged from moderate to very low, with downgrading decisions based on limitations in study design, imprecision and indirectness.Supplementing pregnant women with vitamin D alone probably reduces the risk of pre-eclampsia, gestational diabetes, low birthweight and may reduce the risk of severe postpartum haemorrhage. It may make little or no difference in the risk of having a preterm birth < 37 weeks' gestation. Supplementing pregnant women with vitamin D and calcium probably reduces the risk of pre-eclampsia but may increase the risk of preterm births < 37 weeks (these findings warrant further research). Supplementing pregnant women with vitamin D and other nutrients may make little or no difference in the risk of preterm birth < 37 weeks' gestation or low birthweight (less than 2500 g). Additional rigorous high quality and larger randomised trials are required to evaluate the effects of vitamin D supplementation in pregnancy, particularly in relation to the risk of maternal adverse events.

Lower vitamin D levels during the second trimester are associated with developing gestational diabetes mellitus: an observational cross-sectional study

In this study, we aimed to compare serum 25(OH)D levels in women with and without gestational diabetes mellitus (GDM), and to identify the serum 25(OH)D levels associated with GDM. We recruited 40 women with GDM and 40 healthy pregnant women, aged 20-40 years and in the second trimester, at Gulhane Education and Research Hospital. We excluded women with chronic diseases, preeclampsia, pre-GDM, multiple pregnancies, and those taking medications related to calcium or vitamin D metabolism. We took anthropometric measurements and blood samples during the second trimester. Of the 80 pregnant women, pre-pregnancy body mass index was significantly higher among the GDM group than the healthy group (26.4 ± 5.73 kg/m² vs. 22.6 ± 3.56 kg/m², p = .001). Serum 25(OH)D levels in women with GDM were significantly lower than those in healthy women (16.8 ± 9.90 ng/mL vs. 20.9 ± 8.16 ng/mL, p = .016). The prevalence of severe vitamin D deficiency was as high as 72.5% among women in the GDM group, with a 1.74-fold increased risk of deficient status. Levels of 25(OH)D lower than a cutoff value of 14.0 ng/mL were determined to be related to GDM. These study results suggest that maternal vitamin D deficiency in mid-pregnancy is significantly associated with development of GDM.

A reduction in sedentary behaviour in obese women during pregnancy reduces neonatal adiposity: the DALI randomised controlled trial

AIMS/HYPOTHESIS

Offspring of obese women are at increased risk of features of the metabolic syndrome, including obesity and diabetes. Lifestyle intervention in pregnancy might reduce adverse effects of maternal obesity on neonatal adiposity.

METHODS

In the Vitamin D And Lifestyle Intervention for Gestational Diabetes Mellitus (GDM) Prevention (DALI) lifestyle trial, 436 women with a BMI ≥29 kg/m² were randomly assigned to counselling on healthy eating (HE), physical activity (PA) or HE&PA, or to usual care (UC). In secondary analyses of the lifestyle trial, intervention effects on neonatal outcomes (head, abdominal, arm and leg circumferences and skinfold thicknesses, estimated fat mass, fat percentage, fat-free mass and cord blood leptin) were assessed using multilevel regression analyses. Mediation of intervention effects by lifestyle and gestational weight gain was assessed.

RESULTS

Outcomes were available from 334 neonates. A reduction in sum of skinfolds (-1.8 mm; 95% CI -3.5, -0.2; p = 0.03), fat mass (-63 g; 95% CI -124, -2; p = 0.04), fat percentage (-1.2%; 95% CI -2.4%, -0.04%; p = 0.04) and leptin (-3.80 μg/l; 95% CI -7.15, -0.45; p = 0.03) was found in the HE&PA group, and reduced leptin in female neonates in the PA group (-5.79 μg/l; 95% CI -11.43, -0.14; p = 0.05) compared with UC. Reduced sedentary time, but not gestational weight gain, mediated intervention effects on leptin in both the HE&PA and PA groups.

CONCLUSIONS/INTERPRETATION

The HE&PA intervention resulted in reduced adiposity in neonates. Reduced sedentary time seemed to drive the intervention effect on cord blood leptin. Implications for future adiposity and diabetes risk of the offspring need to be elucidated.

TRIAL REGISTRATION

ISRCTN70595832.

Mediators of Lifestyle Behaviour Changes in Obese Pregnant Women. Secondary Analyses from the DALI Lifestyle Randomised Controlled Trial

A better understanding of what drives behaviour change in obese pregnant overweight women is needed to improve the effectiveness of lifestyle interventions in this group at risk for gestational diabetes (GDM). Therefore, we assessed which factors mediated behaviour change in the Vitamin D and Lifestyle Intervention for GDM Prevention (DALI) Lifestyle Study. A total of 436 women, with pre-pregnancy body mass index ≥29 kg/m², ≤19 + 6 weeks of gestation and without GDM, were randomised for counselling based on motivational interviewing (MI) on healthy eating and physical activity, healthy eating alone, physical activity alone, or to a usual care group. Lifestyle was measured at baseline, and at 24⁻28 and 35⁻37 weeks of gestation. Outcome expectancy, risk perception, task self-efficacy and social support were measured at those same time points and considered as possible mediators of intervention effects on lifestyle. All three interventions resulted in increased positive outcome expectancy for GDM reduction, perceived risk to the baby and increased task self-efficacy. The latter mediated intervention effects on physical activity and reduced sugared drink consumption. In conclusion, our MI intervention was successful in increasing task self-efficacy, which was related to improved health behaviours.

Effect of bariatric surgery before pregnancy on the vascular function in the offspring: protocol of a cross-sectional follow-up study

BACKGROUND

The offspring of obese pregnant women are at risk for adverse metabolic, inflammatory and cardiovascular programming. Comprehensive long-term data are lacking on the contribution of changes in maternal weight after bariatric surgery before pregnancy compared with lifestyle interventions during pregnancy on the cardiovascular programming of the offspring.

METHODS

EFFECTOR is designed as a cross-sectional cohort follow-up study targeting the children of different groups of women who were previously studied during their pregnancy. Four subgroups of children are identified, based on maternal weight characteristics during pregnancy: normal weight women, obese women without any intervention and obese women who underwent a lifestyle intervention during or bariatric surgery before pregnancy. Data collection is performed as a single study visit at home. Data on the sociodemographic situation, food habits and psychomotor development are obtained through questionnaires. During the home visit, extensive anthropometric and vascular assessment is performed. Information on body composition is provided by assessment of body weight and height, bioelectrical impedance analysis, skinfold measurements and ultrasound. Endothelial function is measured by non-invasive peripheral arterial tonometry (EndoPAT 2000). Biomarkers performed in blood and urinalysis conclude the data collection process.

TRIAL REGISTRATION NUMBER

NCT02992106 (Pre-results).

Association between Gestational Weight Gain, Gestational Diabetes Risk, and Obstetric Outcomes: A Randomized Controlled Trial Post Hoc Analysis

Excess gestational weight gain (GWG) is associated with the development of gestational diabetes mellitus (GDM). Lifestyle trials have not achieved much GWG limitation, and have largely failed to prevent GDM. We compared the effect of substantial GWG limitation on maternal GDM risk. Pregnant women with a body mass index (BMI) ≥29 kg/m² <20 weeks gestation without GDM (n = 436) were randomized, in a multicenter trial, to usual care (UC), healthy eating (HE), physical activity (PA), or HE and PA lifestyle interventions. GWG over the median was associated with higher homeostasis model assessment insulin resistance (HOMA-IR) and insulin secretion (Stumvoll phases 1 and 2), a higher fasting plasma glucose (FPG) at 24⁻28 weeks (4.66 ± 0.43 vs. 4.61 ± 0.40 mmol/L, p < 0.01), and a higher rate of caesarean section (38% vs. 27% p < 0.05). The GWG over the median at 35⁻37 weeks was associated with a higher rate of macrosomia (25% vs. 16%, p < 0.05). A post hoc comparison among women from the five sites with a GWG difference >3 kg showed no significance difference in glycaemia or insulin resistance between HE and PA, and UC. We conclude that preventing even substantial increases in GWG after the first trimester has little effect on maternal glycaemia. We recommend randomized controlled trials of effective lifestyle interventions, starting in or before the first trimester.

Cost-effectiveness of healthy eating and/or physical activity promotion in pregnant women at increased risk of gestational diabetes mellitus: economic evaluation alongside the DALI study, a European multicenter randomized controlled trial

Background

Gestational diabetes mellitus (GDM) is associated with perinatal health risks to both mother and offspring, and represents a large economic burden. The DALI study is a multicenter randomized controlled trial, undertaken to add to the knowledge base on the effectiveness of interventions for pregnant women at increased risk for GDM. The purpose of this study was to evaluate the cost-effectiveness of the healthy eating and/or physical activity promotion intervention compared to usual care among pregnant women at increased risk of GDM from a societal perspective.

Methods

An economic evaluation was performed alongside a European multicenter-randomized controlled trial. A total of 435 pregnant women at increased risk of GDM in primary and secondary care settings in nine European countries, were recruited and randomly allocated to a healthy eating and physical activity promotion intervention (HE + PA intervention), a healthy eating promotion intervention (HE intervention), or a physical activity promotion intervention (PA intervention). Main outcome measures were gestational weight gain, fasting glucose, insulin resistance (HOMA-IR), quality adjusted life years (QALYs), and societal costs.

Results

Between-group total cost and effect differences were not significant, besides significantly less gestational weight gain in the HE + PA group compared with the usual care group at 35–37 weeks (−2.3;95%CI:-3.7;-0.9). Cost-effectiveness acceptability curves indicated that the HE + PA intervention was the preferred intervention strategy. At 35–37 weeks, it depends on the decision-makers’ willingness to pay per kilogram reduction in gestational weight gain whether the HE + PA intervention is cost-effective for gestational weight gain, whereas it was not cost-effective for fasting glucose and HOMA-IR. After delivery, the HE + PA intervention was cost-effective for QALYs, which was predominantly caused by a large reduction in delivery-related costs.

Conclusions

Healthy eating and physical activity promotion was found to be the preferred strategy for limiting gestational weight gain. As this intervention was cost-effective for QALYs after delivery, this study lends support for broad implementation.

Trial registration

ISRCTN ISRCTN70595832. Registered 2 December 2011.

Electronic supplementary material

The online version of this article (10.1186/s12966-018-0643-y) contains supplementary material, which is available to authorized users.

Use of dietary assessment tools in randomized trials evaluating diet-based interventions in pregnancy: a systematic review of literature

PURPOSE OF REVIEW

Accurate assessment of dietary intake in interventional trials is the key to evaluate changes in dietary behaviour and compliance. We evaluated the use of dietary assessment tools in randomized trials on diet-based interventions in pregnancy by a systematic review.

RECENT FINDINGS

We updated our previous search (until January 2012) on trials of diet and lifestyle interventions in pregnancy using Medline and EMBASE up to December 2015. Two independent reviewers undertook study selection and data extraction. We assessed the characteristics of dietary assessment tools, the timing and frequency of use and any validation undertaken.Two-thirds (39/58, 67%) of the included studies used some form of tools to assess dietary intake. Multiple days' food diaries were the most commonly used (23/39, 59%). Three studies (3/39, 8%) validated the used tools in a pregnant population. Three studies (3/39, 8%) prespecified the criteria for adherence to the intervention. The use of dietary assessment tools was not associated with study quality, year of publication, journal impact factor, type of journal and the study sample size.

SUMMARY

Although self-reporting dietary assessment tools are widely used in interventional dietary trials in pregnancy, the quality and applicability of existing tools are low.

Correlates of poor mental health in early pregnancy in obese European women

BACKGROUND

Depression during pregnancy is associated with higher maternal morbidity and mortality, and subsequent possible adverse effects on the cognitive, emotional and behavioral development of the child. The aim of the study was to identify maternal characteristics associated with poor mental health, in a group of overweight/obese pregnant women in nine European countries, and thus, to contribute to better recognition and intervention for maternal depression.

METHODS

In this cross-sectional observational study, baseline data from early pregnancy (< 20 weeks) of the DALI (Vitamin D and Lifestyle Intervention for gestational diabetes mellitus prevention) study were analyzed. Maternal mental health was assessed with the World Health Organization Well-Being Index (WHO-5). Women were classified as having a low (WHO-5 ≤ 50) or high wellbeing.

RESULTS

A total of 735 pregnant women were included. The prevalence of having a low wellbeing was 27.2%, 95% CI [24.0, 30.4]. Multivariate analysis showed independent associations between low wellbeing and European ethnicity, OR = .44, 95% CI [.25, .77], shift work, OR = 1.81, 95% CI [1.11, 2.93], insufficient sleep, OR = 3.30, 95% CI [1.96, 5.55], self-efficacy, OR = .95, 95% CI [.92, .98], social support, OR = .94, 95% CI [.90, .99], and pregnancy-related worries (socioeconomic: OR = 1.08, 95% CI [1.02, 1.15]; health: OR = 1.06, 95% CI [1.01, 1.11]; relationship: OR = 1.17, 95% CI [1.05, 1.31]).

CONCLUSIONS

Mental health problems are common in European overweight/obese pregnant women. The identified correlates might help in early recognition and subsequent treatment of poor mental health problems during pregnancy. This is important to reduce the unfavorable effects of poor mental health on pregnancy outcomes.

TRIAL REGISTRATION

ISRCTN70595832 , 02.12.2011.

Combined diet and exercise interventions for preventing gestational diabetes mellitus

BACKGROUND

Gestational diabetes mellitus (GDM) is associated with a wide range of adverse health consequences for women and their infants in the short and long term. With an increasing prevalence of GDM worldwide, there is an urgent need to assess strategies for GDM prevention, such as combined diet and exercise interventions. This is an update of a Cochrane review that was first published in 2015.

OBJECTIVES

To assess the effects of diet interventions in combination with exercise interventions for pregnant women for preventing GDM, and associated adverse health consequences for the mother and her infant/child.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (27 November 2016) and reference lists of retrieved studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and cluster-RCTs, comparing combined diet and exercise interventions with no intervention (i.e. standard care), that reported on GDM diagnosis as an outcome. Quasi-RCTs were excluded. Cross-over trials were not eligible for inclusion. We planned to include RCTs comparing two or more different diet/exercise interventions, however none were identified.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study eligibility, extracted data, assessed the risk of bias of the included trials and assessed quality of evidence for selected maternal and infant/child outcomes using the GRADE approach. We checked data for accuracy.

MAIN RESULTS

In this update, we included 23 RCTs (involving 8918 women and 8709 infants) that compared combined diet and exercise interventions with no intervention (standard care). The studies varied in the diet and exercise programs evaluated and health outcomes reported. None reported receiving funding from a drug manufacturer or agency with interests in the results. Overall risk of bias was judged to be unclear due to the lack of methodological detail reported. Most studies were undertaken in high-income countries.For our primary review outcomes, there was a possible reduced risk of GDM in the diet and exercise intervention group compared with the standard care group (average risk ratio (RR) 0.85, 95% confidence interval (CI) 0.71 to 1.01; 6633 women; 19 RCTs; Tau² = 0.05; I² = 42%; P = 0.07; moderate-quality evidence). There was also a possible reduced risk of caesarean section (RR 0.95, 95% CI 0.88 to 1.02; 6089 women; 14 RCTs; moderate-quality evidence). No clear differences were seen between groups for pre-eclampsia (RR 0.98, 95% CI 0.79 to 1.22; 5366 participants; 8 RCTs; low-quality evidence), pregnancy-induced hypertension and/or hypertension (average RR 0.78, 95% CI 0.47 to 1.27; 3073 participants; 6 RCTs; Tau² = 0.19; I² = 62%; very low-quality evidence), perinatal mortality (RR 0.82, 95% CI 0.42 to 1.63; 3757 participants; 2 RCTs; low-quality evidence) or large-for-gestational age (RR 0.93, 95% CI 0.81 to 1.07; 5353 participants; 11 RCTs; low-quality evidence). No data were reported for infant mortality or morbidity composite.Subgroup analyses (based on trial design, maternal body mass index (BMI) and ethnicity) revealed no clear differential treatment effects. We were unable to assess the impact of maternal age, parity and specific features of the diet and exercise interventions. Findings from sensitivity analyses (based on RCT quality) generally supported those observed in the main analyses. We were not able to perform subgroup analyses based on maternal age, parity or nature of the exercise/dietary interventions due to the paucity of information/data on these characteristics and the inability to meaningfully group intervention characteristics.For most of the secondary review outcomes assessed using GRADE, there were no clear differences between groups, including for perineal trauma (RR 1.27, 95% CI 0.78 to 2.05; 2733 participants; 2 RCTs; moderate-quality evidence), neonatal hypoglycaemia (average RR 1.42, 95% CI 0.67 to 2.98; 3653 participants; 2 RCTs; Tau² = 0.23; I² = 77%; low quality evidence); and childhood adiposity (BMI z score) (MD 0.05, 95% CI -0.29 to 0.40; 794 participants; 2 RCTs; Tau² = 0.04; I² = 59%; low-quality evidence). However, there was evidence of less gestational weight gain in the diet and exercise intervention group compared with the control group (mean difference (MD) -0.89 kg, 95% CI -1.39 to -0.40; 5052 women; 16 RCTs; Tau² = 0.37; I² = 43%;moderate-quality evidence). No data were reported for maternal postnatal depression or type 2 diabetes; childhood/adulthood type 2 diabetes, or neurosensory disability.

AUTHORS' CONCLUSIONS

Moderate-quality evidence suggests reduced risks of GDM and caesarean section with combined diet and exercise interventions during pregnancy as well as reductions in gestational weight gain, compared with standard care. There were no clear differences in hypertensive disorders of pregnancy, perinatal mortality, large-for-gestational age, perineal trauma, neonatal hypoglycaemia, and childhood adiposity (moderate- tovery low-quality evidence).Using GRADE methodology, the evidence was assessed as moderate to very low quality. Downgrading decisions were predominantly due to design limitations (risk of bias), and imprecision (uncertain effect estimates, and at times, small sample sizes and low event rates), however two outcomes (pregnancy-induced hypertension/hypertension and neonatal hypoglycaemia), were also downgraded for unexplained inconsistency (statistical heterogeneity).Due to the variability of the diet and exercise components tested in the included studies, the evidence in this review has limited ability to inform practice. Future studies could describe the interventions used in more detail, if and how these influenced behaviour change and ideally be standardised between studies. Studies could also consider using existing core outcome sets to facilitate more standardised reporting.

Epidemiology of gestational diabetes mellitus according to IADPSG/WHO 2013 criteria among obese pregnant women in Europe

AIMS/HYPOTHESIS

Accurate prevalence estimates for gestational diabetes mellitus (GDM) among pregnant women in Europe are lacking owing to the use of a multitude of diagnostic criteria and screening strategies in both high-risk women and the general pregnant population. Our aims were to report important risk factors for GDM development and calculate the prevalence of GDM in a cohort of women with BMI ≥29 kg/m2 across 11 centres in Europe using the International Association of the Diabetes and Pregnancy Study Groups (IADPSG)/WHO 2013 diagnostic criteria.

METHODS

Pregnant women (n = 1023, 86.3% European ethnicity) with a BMI ≥29.0 kg/m2 enrolled into the Vitamin D and Lifestyle Intervention for GDM Prevention (DALI) pilot, lifestyle and vitamin D studies of this pan-European multicentre trial, attended for an OGTT during pregnancy. Demographic, anthropometric and metabolic data were collected at enrolment and throughout pregnancy. GDM was diagnosed using IADPSG/WHO 2013 criteria. GDM treatment followed local policies.

RESULTS

The number of women recruited per country ranged from 80 to 217, and the dropout rate was 7.1%. Overall, 39% of women developed GDM during pregnancy, with no significant differences in prevalence across countries. The prevalence of GDM was high (24%; 242/1023) in early pregnancy. Despite interventions used in the DALI study, a further 14% (94/672) had developed GDM when tested at mid gestation (24-28 weeks) and 13% (59/476) of the remaining cohort at late gestation (35-37 weeks). Demographics and lifestyle factors were similar at baseline between women with GDM and those who maintained normal glucose tolerance. Previous GDM (16.5% vs 7.9%, p = 0.002), congenital malformations (6.4% vs 3.3%, p = 0.045) and a baby with macrosomia (31.4% vs 17.9%, p = 0.001) were reported more frequently in those who developed GDM. Significant anthropometric and metabolic differences were already present in early pregnancy between women who developed GDM and those who did not.

CONCLUSIONS/INTERPRETATION

The prevalence of GDM diagnosed by the IADPSG/WHO 2013 GDM criteria in European pregnant women with a BMI ≥29.0 kg/m2 is substantial, and poses a significant health burden to these pregnancies and to the future health of the mother and her offspring. Uniform criteria for GDM diagnosis, supported by robust evidence for the benefits of treatment, are urgently needed to guide modern GDM screening and treatment strategies.

Is a motivational interviewing based lifestyle intervention for obese pregnant women across Europe implemented as planned? Process evaluation of the DALI study

BACKGROUND

Process evaluation is an essential part of designing and assessing complex interventions. The vitamin D and lifestyle intervention study (DALI) study is testing different strategies to prevent development of gestational diabetes mellitus among European obese pregnant women with a body mass index ≥29 kg/m². The intervention includes guidance on physical activity and/or healthy eating by a lifestyle coach trained in motivational interviewing (MI). The aim of this study was to assess the process elements: reach, dose delivered, fidelity and satisfaction and to investigate whether these process elements were associated with changes in gestational weight gain (GWG).

METHODS

Data on reach, dose delivered, fidelity, and satisfaction among 144 participants were collected. Weekly recruitment reports, notes from meetings, coach logs and evaluation questionnaires (n = 110) were consulted. Fidelity of eight (out of twelve) lifestyle coach practitioners was assessed by analysing audio recorded counselling sessions using the MI treatment integrity scale. Furthermore, associations between process elements and GWG were assessed with linear regression analyses.

RESULTS

A total of 20% of the possible study population (reach) was included in this analysis. On average 4.0 (of the intended 5) face-to-face sessions were delivered. Mean MI fidelity almost reached 'expert opinion' threshold for the global scores, but was below 'beginning proficiency' for the behavioural counts. High variability in quality of MI between practitioners was identified. Participants were highly satisfied with the intervention, the lifestyle coach and the intervention materials. No significant associations were found between process elements and GWG.

CONCLUSION

Overall, the intervention was well delivered and received by the study population, but did not comply with all the principles of MI. Ensuring audio recording of lifestyle sessions throughout the study would facilitate provision of individualized feedback to improve MI skills. A larger sample size is needed to confirm the lack of association between process elements and GWG.

TRIAL REGISTRATION

ISRCTN registry: ISRCTN70595832 ; Registered 12 December 2011.

INTER-ACT: prevention of pregnancy complications through an e-health driven interpregnancy lifestyle intervention - study protocol of a multicentre randomised controlled trial

Background

Excessive maternal pre-pregnancy and gestational weight gain are related to pregnancy- and birth outcomes. The interpregnancy time window offers a unique opportunity to intervene in order to acquire a healthy lifestyle before the start of a new pregnancy.

Methods

INTER-ACT is an e-health driven multicentre randomised controlled intervention trial targeting women at high risk of pregnancy- and birth related complications. Eligible women are recruited for the study at day 2 or 3 postpartum. At week 6 postpartum, participants are randomised into the intervention or control arm of the study. The intervention focuses on weight, diet, physical activity and mental well-being, and comprises face-to-face coaching, in which behavioural change techniques are central, and use of a mobile application, which is Bluetooth-connected to a weighing scale and activity tracker. The intervention is rolled out postpartum (4 coaching sessions between week 6 and month 6) and in a new pregnancy (3 coaching sessions, one in each trimester of pregnancy); the mobile app is used throughout the two intervention phases. Data collection includes data from the medical record of the participants (pregnancy outcomes and medical history), anthropometric data (height, weight, waist- and hip circumferences, skinfold thickness and body composition by bio-electrical impedance analysis), data from the mobile app (physical activity and weight; intervention group only) and questionnaires (socio-demographics, breastfeeding, food intake, physical activity, lifestyle, psychosocial factors and process evaluation). Medical record data are collected at inclusion and at delivery of the subsequent pregnancy. All other data are collected at week 6 and month 6 postpartum and every subsequent 6 months until a new pregnancy, and in every trimester in the new pregnancy. Primary outcome is the composite endpoint score of pregnancy-induced hypertension, gestational diabetes mellitus, caesarean section, and large-for-gestational-age infant in the subsequent pregnancy.

Discussion

INTER-ACT is a unique randomised controlled lifestyle intervention trial in its implementation between pregnancies and during the subsequent pregnancy, with an e-health driven approach.

Trial registration

ClinicalTrials.gov Identifier: NCT02989142. Registered August 2016.

Effect of Physical Activity and/or Healthy Eating on GDM Risk: The DALI Lifestyle Study

CONTEXT

Lifestyle approaches for preventing gestational diabetes mellitus (GDM) have produced mixed results.

OBJECTIVE

The aim of the present study was to compare the effectiveness of 3 lifestyle interventions [healthy eating (HE), physical activity (PA), and both HE and PA (HE+PA)] with usual care (UC) in reducing GDM risk.

DESIGN

The present study was a multicenter randomized controlled trial conducted from 2012 to 2014 [the DALI (vitamin D and lifestyle intervention for GDM prevention) lifestyle study].

SETTING

The study occurred at antenatal clinics across 11 centers in 9 European countries.

PATIENTS

Consecutive pregnant women at <20 weeks of gestation with a body mass index (BMI) of ≥29 kg/m2 and without GDM using the International Association of Diabetes and Pregnancy Study Group criteria (n = 436). For the intervention, women were randomized, stratified by site, to UC, HE, PA, or HE+PA. The women received 5 face-to-face and ≤4 telephone coaching sessions using the principles of motivational interviewing. A gestational weight gain (GWG) <5 kg was targeted. The coaches received standardized training and an intervention toolkit tailored to their culture and language.

MAIN OUTCOME MEASURES

The endpoints were the GWG at 35 to 37 weeks and the fasting glucose and insulin sensitivity [homeostasis model assessment insulin resistance (HOMA-IR)] at 24 to 28 weeks.

RESULTS

We randomized 108 women to HE+PA, 113 to HE, 110 to PA, and 105 to UC. In the HE+PA group, but not HE or PA alone, women achieved substantially less GWG than did the controls (UC) by 35 to 37 weeks (-2.02; 95% confidence interval, -3.58 to -0.46 kg). Despite this reduction, no improvements were seen in fasting or postload glucose levels, insulin concentrations, or HOMA-IR. The birthweights and large and small for gestational age rates were similar.

CONCLUSIONS

The combined HE+PA intervention was able to limit GWG but did not reduce fasting glycemia. Thus, lifestyle changes alone are unlikely to prevent GDM among women with a BMI of ≥29 kg/m2.

Integration of VDR genome wide binding and GWAS genetic variation data reveals co-occurrence of VDR and NF-κB binding that is linked to immune phenotypes

Background

The nuclear hormone receptor superfamily acts as a genomic sensor of diverse signals. Their actions are often intertwined with other transcription factors. Nuclear hormone receptors are targets for many therapeutic drugs, and include the vitamin D receptor (VDR). VDR signaling is pleotropic, being implicated in calcaemic function, antibacterial actions, growth control, immunomodulation and anti-cancer actions. Specifically, we hypothesized that the biologically significant relationships between the VDR transcriptome and phenotype-associated biology could be discovered by integrating the known VDR transcription factor binding sites and all published trait- and disease-associated SNPs. By integrating VDR genome-wide binding data (ChIP-seq) with the National Human Genome Research Institute (NHGRI) GWAS catalog of SNPs we would see where and which target gene interactions and pathways are impacted by inherited genetic variation in VDR binding sites, indicating which of VDR’s multiple functions are most biologically significant.

Results

To examine how genetic variation impacts VDR function we overlapped 23,409 VDR genomic binding peaks from six VDR ChIP-seq datasets with 191,482 SNPs, derived from GWAS-significant SNPs (Lead SNPs) and their correlated variants (r² > 0.8) from HapMap3 and the 1000 genomes project. In total, 574 SNPs (71 Lead and 503 SNPs in linkage disequilibrium with Lead SNPs) were present at VDR binding loci and associated with 211 phenotypes. For each phenotype a hypergeometric test was used to determine if SNPs were enriched at VDR binding sites. Bonferroni correction for multiple testing across the 211 phenotypes yielded 42 SNPs that were either disease- or phenotype-associated with seven predominately immune related including self-reported allergy; esophageal cancer was the only cancer phenotype. Motif analyses revealed that only two of these 42 SNPs reside within a canonical VDR binding site (DR3 motif), and that 1/3 of the 42 SNPs significantly impacted binding and gene regulation by other transcription factors, including NF-κB. This suggests a plausible link for the potential cross-talk between VDR and NF-κB.

Conclusions

These analyses showed that VDR peaks are enriched for SNPs associated with immune phenotypes suggesting that VDR immunomodulatory functions are amongst its most important actions. The enrichment of genetic variation in non-DR3 motifs suggests a significant role for the VDR to bind in multimeric complexes containing other transcription factors that are the primary DNA binding component. Our work provides a framework for the combination of ChIP-seq and GWAS findings to provide insight into the underlying phenotype-associated biology of a given transcription factor.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-017-3481-4) contains supplementary material, which is available to authorized users.

Primary prevention of gestational diabetes mellitus through nutritional factors: a systematic review

BACKGROUND

Gestational diabetes mellitus (GDM), defined as any degree of glucose intolerance with onset during pregnancy, is increasing worldwide, mostly because obesity among women of reproductive age is continuously escalating. GDM is associated with adverse maternal and fetal outcomes. The aim of this article was to systematically review literature on the effectiveness of nutritional factors before or during pregnancy to prevent GDM.

METHODS

We assessed the primary prevention of GDM through nutritional factors, as diet and supplements. We searched on PubMed, Cochrane Databases and ClinicalTrials.gov from inception to June 2016. Clinical trials and adjusted prospective cohort studies were included.

RESULTS

Eight clinical trials and twenty observational studies assessing the association between dietary factors and primary prevention of GDM were included. Furthermore, six clinical trials and two observational studies related to supplements were also added. Only two nutritional interventions were found to significantly reduce the incidence of GDM, besides the supplements. However, the observational studies showed that a higher adherence to a healthier dietary pattern can prevent the incidence of GDM, especially in high risk population before getting pregnant.

CONCLUSIONS

The results indicate that there may be some benefits of some nutritional factors to prevent GDM. However, better-designed studies are required to generate higher quality evidence. At the moment, no strong conclusions can be drawn with regard to the best intervention for the prevention of GDM.