The effects of vitamin and mineral supplementation on women with gestational diabetes mellitus

Investigating the impact of trial retractions on the healthcare evidence ecosystem (VITALITY Study I): retrospective cohort study

OBJECTIVE

To investigate the impact of retracted trials on the production and use of healthcare evidence in the evidence ecosystem.

DESIGN

Retrospective cohort study based on forward citation searching.

DATA SOURCES

Retraction Watch up to 5 November 2024.

STUDY SELECTION

Randomised controlled trials in humans that were retracted for any reason.

METHODS

Forward citation searching via Google Scholar and Scopus was used to identify evidence synthesis research (21 November 2024) that quantitatively incorporated retracted trials. Data were independently extracted by two groups of researchers. The results of meta-analyses were updated after exclusion of the retracted trials. The proportions of meta-analyses that changed direction of the pooled effect and/or the significance of the P value were estimated. A generalised linear mixed model was used to investigate the association between the number of included studies and the impact, measured by odds ratio and 95% confidence interval (CI). The impact of distorted evidence on clinical practice guidelines was also investigated on the basis of citation searching.

RESULTS

The searches identified 1330 retracted trials and 847 systematic reviews that quantitatively synthesised retracted trials, with a total of 3902 meta-analyses that could be replicated. After the potential clustering effects were accounted for, the exclusion of the retracted trials led to a change in the direction of the pooled effect in 8.4% (95% CI 6.8% to 10.1%), in its statistical significance in 16.0% (14.2% to 17.9%), and in both direction and significance in 3.9% (2.5% to 5.2%) and a >50% change in the magnitude of the effect in 15.7% (13.5% to 17.9%). An obvious non-linear association existed between the number of included studies and the impact on the results, with a lower number of studies having higher impact (eg, for 10 studies versus ≥20 studies, change of direction: odds ratio 2.63, 95% CI 1.29 to 5.38; P<0.001). Evidence from 68 systematic reviews with conclusions distorted by retracted trials was used in 157 guideline documents.

CONCLUSION

Retracted trials have a substantial impact on the evidence ecosystem, including evidence synthesis, clinical practice guidelines, and evidence based clinical practice. Evidence generators, synthesisers, and users must pay attention to this problem, and feasible approaches that assist with easier identification and correction of such potential contamination are needed.

STUDY REGISTRATION

Open Science Framework (https://osf.io/7eazq/).

Antioxidant Supplementation for Management of Gestational Diabetes Mellitus in Pregnancy: A Systematic Review and Meta-Analysis of Randomised Controlled Trials

PURPOSE OF REVIEW

Gestational diabetes mellitus (GDM) is the most common medical complication of pregnancy globally. Hyperglycaemia and associated production of reactive oxygen species can lead to oxidative stress in pregnancy. However, the potential effectiveness of increased antioxidant intake in the management of GDM has not been widely examined. Its usefulness alongside medical nutrition therapy (MNT) for assisting glycaemic control in women with GDM is poorly understood. This review aimed to establish the effect of antioxidant supplementation on the risk and management of gestational diabetes mellitus (GDM).

RECENT FINDINGS

A systematic review of intervention studies was conducted based on PRISMA guidelines. Databases searched were MEDLINE, CINAHL, Global Health, Scopus, Embase and Cochrane until September 2024. Random effects meta-analyses using Cochrane Review Manager software to establish the effect of antioxidant supplementation on glucose outcomes in women with GDM were conducted. A total of 13 studies (1380 participants) were included in the review with four different antioxidants used (selenium (n = 3); alpha-lipoic (n = 4); zinc (n = 5); e-3-gallate (n = 1)). Significant pre-post differences between antioxidant supplementation and control groups were found for fasting insulin (SMD, 95%CI) (-0.97 [-1.69 -0.24]; p = 0.009, HOMA-IR (-0.90 [-1.25, -0.54]; p < 0.0000, HOMA-B (-0.86 [-1.05, -0.67]; p < 0.00001 and QUICKI (1.09 [0.32,1.87]; p = 0.005 Heterogeneity was substantial (I2 > 50%, p < 0.05) for all models except for HOMA-B (I2 = 0%, p > 0.05). Antioxidant supplementation has possible benefit as an adjunct therapy to current dietary management for women with GDM. Further clinical trials are needed to establish the preferred type and dosage of antioxidants likely to be effective.

Synergistic Effect of Maternal Micronutrient Supplementation on ORFV DNA Vaccine Immune Response in a Pregnant Model

Contagious ecthyma is a contagious zoonotic disease caused by the Orf virus that can infect farm animals and humans, but no vaccine is available for pregnant mothers. Excessive oxidative stress during pregnancy can suppress the vaccine immune response in pregnant mothers; hence, maternal micronutrient supplementation could effectively improve the immune response, health, and oxidative status during pregnancy. In this study, we employed an 8-week-old pregnant rat model to receive a single intramuscular dose of 200 µg of ORF DNA vaccine with or without vitamin E and selenium supplementation to evaluate their effect on immune responses (specific IgG and IgG isotypes), oxidative stress, liver enzymes, and blood glucose levels in maternal-neonatal serum and milk secretions. Additionally, antioxidant-related gene expressions were analyzed in the maternal placenta and pups' liver. The results showed that supplementation of vitamin E and selenium with ORF DNA vaccination increased the production of specific antibody and IgG isotypes (IgG1 and IgG2a) and reduced the oxidative stress in neonatal-maternal serum and milk compared to both the control group and those vaccinated without supplementation (p < 0.05). Notably, the ORF DNA vaccine did not cause oxidative stress and hepatic damage. However, combined supplementation of vitamin E and selenium with DNA vaccination significantly decreased serum malondialdehyde (MDA) levels and improved the antioxidant-related enzyme activities of glutathione peroxidase (GPX), superoxide dismutase 1 (SOD1), and selenoprotein P (SELP) in the maternal placenta and liver of pups (p < 0.05). In conclusion, maternal supplementation of vitamin E and selenium enhanced the immune responses of the ORF DNA vaccine by mitigating oxidative stress in pregnant rats and could thus be a promising strategy for better health outcomes for both mothers and neonates.

Association Between Zinc Status and Insulin Resistance/Sensitivity Check Indexes in Gestational Diabetes Mellitus

Gestational diabetes mellitus (GDM) is considered the most common metabolic disorder of the pregnancy period. It is characterized by pancreatic beta-cell dysfunction in the setting of chronic insulin resistance. Zinc is a nutrient involved in numerous metabolic processes and shows a relationship with glycometabolic disorders and GDM. The latest data have demonstrated the association of zinc with insulin sensitivity and resistance. The exact role of zinc in the connection with indexes of insulin resistance and insulin sensitivity is still not fully clarified. The aim of the study is to analyze the newly calculated indexes Glu/Zn, Ins/Zn, and HOMA-IR/Zn as surrogate markers to explore the correlation between serum zinc status and some indexes of insulin sensitivity and insulin resistance. The possible role of these indexes as markers of insulin resistance in pregnant women was analyzed too. An ROC analysis demonstrated that HOMA-IR/Zn with AUC 0.989, p < 0.001 (95% CI 0.967-1.000) and Ins/Zn with AUC 0.947, p < 0.001 (95% CI 0.889-1.000) in the GDM group, and only HOMA-IR/Zn index with AUC 0.953, p < 0.001 (95% CI 0.877-1.000) in healthy pregnant women, have good power as markers of insulin resistance in both groups. We speculate that these new ratios could be suitable for the assessment of pregnant women at high risk of insulin resistance development and, probably, for the evaluation of the specific pathophysiologic characteristics of women with GDM.

Knowledge, Attitudes, and Perceptions of Maternity Care Providers on the Implementation of Calcium Supplementation during Pregnancy in Three Public Hospitals in Argentina: A Qualitative Study

The aim of this study was to explore maternity care providers' knowledge, attitudes, and perceptions about the use of calcium supplements during pregnancy for the prevention of preeclampsia in three hospitals from Metropolitan Buenos Aires, Argentina. We conducted semi-structured interviews and followed a thematic analysis framework. Maternity care providers' knowledge, attitudes, and practices regarding calcium supplementation during pregnancy are linked to barriers to the potential implementation of calcium supplementation. Free provision of calcium supplements by the government, coupled with training that reinforces the scientific evidence supporting their use to prevent preeclampsia, along with documented recommendations from credible sources, would be crucial to ensure that health providers adopt the use of calcium supplements in antenatal care. Future studies should assess pregnant women and policymakers' perceptions about calcium supplementation during pregnancy, as well as local infrastructure to provide access to free-of-charge calcium supplements in antenatal care settings. Economic evaluation with local information could inform policymakers and advocate for the implementation of strategies to reduce preeclampsia.

Dietary management of gestational diabetes: A review

Gestational diabetes mellitus (GDM) is a common condition in pregnant women that can affect the health of both the mother and the fetus. A healthy diet reduces the risk of GDM, while on the contrary, an unhealthy diet can increase the risk of developing GDM. Dietary interventions remain an important way to control GDM at this time. However, real-life diets are complex and varied, and the effect of these diets on gestational diabetes is unknown. This article summarizes research related to dietary control of GDM. Hopefully, this will help with dietary interventions for people with GDM.

Effect of different nutrients on blood glucose, inflammatory response and oxidative stress in gestational diabetes mellitus: a network meta-analysis

We searched PubMed, Web of Science, Embase, The Cochrane Library, China Biomedical Literature Database and other databases from inception to June 2023. The included studies were randomised controlled trials (RCT). The studies were screened by four authors, divided into two independent pairs. A total of eighteen studies were included, including 1362 patients, involving twelve intervention measures. The different nutrients had a significant effect on improving blood glucose, reducing inflammation levels and reducing oxidative stress compared with placebo (P < 0.05). Cumulative probability ranking showed that vitamin A + vitamin D + vitamin E ranked first in lowering fasting blood glucose (standardised mean difference (SMD) = 41.30, 95 % CI (2.07, 825.60)) and postprandial 2-h blood glucose (SMD = 15.19, 95 % CI (4.16, 55.53)). In terms of insulin resistance index, the first highest probability ranking is vitamin D (SMD = 5.12, 95 % CI (0.76, 34.54)). In terms of reducing the high-sensitivity C-reactive protein level, the first in probability ranking is VE (SMD = 2.58, 95 % CI (1.87,3.55)). The results of cumulative probability ranking showed that Mg + Zn + Ca + VD ranked first in reducing TNF-α (SMD = 1.90, 95% CI (0.40, 9.08)) and IL-6 (SMD = 1.83, 95 % CI (0.37, 9.12)). In terms of reducing malondialdehyde levels, the first ranked probability is VB1 (SMD = 4.99, 95 % CI (1.85, 13.46)). Cumulative probability ranking results showed that Ca + VD ranked first in reducing total antioxidant capacity (SMD = 0.66,95 % CI (0.38, 1.15)) and glutathione (SMD = 1.39, 95 % CI (0.43, 4.56)). In conclusion, nutritional interventions have significant effects on improving blood glucose, inflammatory levels and oxidative stress in patients with gestational diabetes. Due to the high uncertainty in the results and differences in the number and quality of studies included, the reliability of the conclusions still needs to be validated by conducting large-sample, high-quality RCT studies.

The Association Between Serum Magnesium Levels and Gestational Diabetes Mellitus: a Systematic Review and Meta-Analysis

Observational studies suggest that the potential role of magnesium remains controversial in gestational diabetes mellitus (GDM). This meta-analysis aims to consolidate the available information from observational studies that have focused on the relationship between magnesium levels and GDM. A systematic and comprehensive literature search was conducted in PubMed, Embase, Web of Science, CNKI, and Wanfang databases. Data were extracted independently by two investigators. Standardized mean differences (SMD) and 95% confidence intervals (CIs) were used to summarize the circulating magnesium levels (CI). This meta-analysis included a total of 17 studies involving 2858 participants including 1404 GDM cases and 1454 healthy controls, which showed that magnesium levels were significantly lower in GDM compared to healthy controls (SMD: - 0.35; 95% CI: - 0.62, - 0.07, P = 0.013). Likewise, the same phenomenon was observed in the third trimester (SMD =  - 1.07; 95% CI: - 1.84 to - 0.29, P = 0.007). Other subgroup analyses revealed that this trend of decreasing magnesium concentration was only observed in Europeans (SMD =  - 0.64; 95% CI: - 0.90, - 0.38, P < 0.0001). This meta-analysis revealed that serum magnesium levels were lower in patients with GDM than in healthy pregnant women, and this discrepancy was most pronounced in European populations and during the third trimester. Nevertheless, current evidence suggests that circulating magnesium deficiency is associated with gestational diabetes; the challenge for the future is to further elucidate the possible benefits of preventing gestational diabetes through magnesium supplementation.

The association between the dietary inflammatory index and gestational diabetes mellitus: A systematic review of observational studies

BACKGROUND & AIMS

Unhealthy dietary habits contribute to low-grade chronic inflammation that is known to be associated with metabolic disorders and pregnancy complications such as gestational diabetes mellitus (GDM). The dietary inflammatory index (DII) is a scoring system for assessing the inflammatory potential of various nutrients and foods. This systematic review aims to investigate the current state of evidence on the association between DII and GDM in pregnant women.

METHODS

PubMed, Scopus and Web of Science electronic databases were systematically searched for relevant English-language articles published up to February 2023. This study was developed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (CRD42022382813).

RESULTS

This review included seven studies (98,115 participants) from five countries. In total, two case-control studies have shown a positive association between DII and GDM. In contrast, three of five cohort studies found no association between dietary inflammatory potential and the risk of developing GDM.

CONCLUSION

We found some controversial results due to the small number of studies, with major heterogeneity in research design and findings. Collectively, the current study does not support an association between the DII score and the risk of gestational diabetes. Further, longitudinal studies are needed to elucidate the association between dietary inflammatory potential and GDM.

Assessment of energy and nutrient intake of sri lankan mothers with prior gestational diabetes mellitus at 6-week postpartum: A community-based study

Background

Gestational diabetes mellitus (GDM) is one of the leading causes for the future diabetes. Diet modification is an imperative part in attenuating this progression.

Objectives

This study assessed energy and nutrient intakes of Sri Lankan mothers at 6 weeks after delivery, with the aim of developing specific dietary guidelines for postpartum mothers with GDM.

Materials and Methods

A community-based, descriptive cross-sectional survey was conducted as a part of a quasi-experimental study. Nutrient and energy intakes were assessed among 100 mothers using 24-h dietary recall and a validated food frequency questionnaire. Energy and nutrient intakes were analyzed using NutriSurvey 2007 (EBISpro, Germany) which was modified for native food recipes and food composition tables for Sri Lanka.

Results

The mean ± standard deviation intakes of total calories, carbohydrate, protein, and fat were 2817 ± 984 kcal, 445 ± 186 g, 95 ± 39 g, and 87 ± 58 g, respectively. The total calorie intake was significantly higher when compared to recommended levels based on the body mass index in both normal weight (3033 ± 1122 vs. 2300 kcal/d; P < 0.00) and overweight or obese (2759 ± 944 vs. 1800 kcal/d; P < 0.00) postpartum women. In the obese group, daily carbohydrate, fat, and protein intakes were significantly higher than the recommended values (P < 0.00). Folic acid intake was lower in both normal (23.7 vs. 400; P < 0.001) and obese or overweight (63 vs. 400; P < 0.001) groups.

Conclusion

The study indicated that in majority of the mothers with GDM, the daily calorie and carbohydrate intakes were higher than the recommended. The findings suggest the need for developing a scientifically feasible and culturally acceptable dietary modification program. All macronutrients were taken more than the recommended amounts, especially in the overweight/obese group.

Association of vitamin D and magnesium with insulin sensitivity and their influence on glycemic control

Insulin resistance increases the risk of developing diabetes, and the degree of resistance influences the glycemic control of patients with diabetes. Numerous researchers have focused on improving insulin sensitivity in order to prevent diabetes-related complications and other chronic diseases. Several studies have also linked vitamin D levels to insulin secretion and resistance, given that both vitamin D and its receptor complex play important roles in regulating pancreatic β-cells. It has been suggested that vitamin D supplementation improves vitamin D levels, but further research is needed to confirm this as neither insulin function nor glycemic control improves when vitamin D levels increase. Magnesium is a cofactor for many enzymes. Although the role of magnesium in the management of diabetes has long been evaluated, it has not yet been determined whether magnesium supplements improve insulin function. However, several researchers have found that patients with good glycemic control have high magnesium levels. Magnesium is closely related to vitamin D and is necessary for the transport and activation of vitamin D in humans. Combined supplementation with vitamin D and magnesium improves glycemic control in patients with diabetes.

Insulin Requirement for Gestational Diabetes Control Is Related to Higher Vitamin D Levels up to 1 Year Postpartum: A Prospective Cohort Study

Vitamin D deficiency is highly prevalent in pregnant women and has been related to a higher risk of gestational diabetes mellitus (GDM). The aim of this study is to analyze vitamin D status evolution in a population of pregnant women with and without GDM. Two-hundred women were included from January 2019 to February 2022 as follows: Control group -CG-, Lifestyle group -LG- (GDM not requiring insulin), and Insulin group -IG- (GDM requiring insulin). Visits were carried out at baseline, antenatal, postpartum, and 1 year after birth. Vitamin D levels, weight, and insulin resistance were measured at every visit. Data about the season, vitamin D supplementation, Mediterranean diet adherence, and physical activity were included. In the three groups, 134 women were included in the CG, 43 in the LG, and 23 in the IG. Vitamin D levels were similar among the groups at baseline, but they were significantly higher in the LG and IG in comparison with the CG at the antenatal visit and significantly higher in the IG vs. CG and LG at the postpartum and 1 year after birth visits. Vitamin D levels were independently related to vitamin D supplementation and the season at baseline, to the season and belonging to the LG or IG at the antenatal visit, and were only independently associated with belonging to the IG at postpartum and 1 year after birth visits. In conclusion, in our population, women with GDM requiring insulin had higher levels of vitamin D in comparison with those not requiring insulin and healthy controls at postpartum and 1 year after pregnancy. Requiring insulin during pregnancy seems to be a factor that independently determines the levels of vitamin D until 1 year after birth. More studies are required to reproduce these data in other populations and to elucidate the mechanisms underlying these findings.

COVID-19 and Gestational Diabetes: The Role of Nutrition and Pharmacological Intervention in Preventing Adverse Outcomes

Pregnant women with GDM affected by COVID-19 seem to be at higher risk of adverse maternal and neonatal outcomes, especially those with overweight or obesity. Good glycemic control seems to be the most effective measure in reducing the risk of GDM and severe COVID-19. For such purposes, the Mediterranean diet, micronutrient supplementation, and physical activity are considered the first line of treatment. Failure to achieve glycemic control leads to the use of insulin, and this clinical scenario has been shown to be associated with an increased risk of adverse maternal and neonatal outcomes. In this review, we explore the current evidence pertaining to the pathogenesis of SARS-CoV-2 leading to the main complications caused by COVID-19 in patients with GDM. We also discuss the incidence of complications caused by COVID-19 in pregnant women with GDM according to their treatment.

Impact on Glucose Homeostasis: Is Food Biofortified with Molybdenum a Workable Solution? A Two-Arm Study

Diabetes is expected to increase up to 700 million people worldwide with type 2 diabetes being the most frequent. The use of nutritional interventions is one of the most natural approaches for managing the disease. Minerals are of paramount importance in order to preserve and obtain good health and among them molybdenum is an essential component. There are no studies about the consumption of biofortified food with molybdenum on glucose homeostasis but recent studies in humans suggest that molybdenum could exert hypoglycemic effects. The present study aims to assess if consumption of lettuce biofortified with molybdenum influences glucose homeostasis and whether the effects would be due to changes in gastrointestinal hormone levels and specifically Peptide YY (PYY), Glucagon-Like Peptide 1 (GLP-1), Glucagon-Like Peptide 2 (GLP-2), and Gastric Inhibitory Polypeptide (GIP). A cohort of 24 people was supplemented with biofortified lettuce for 12 days. Blood and urine samples were obtained at baseline (T0) and after 12 days (T2) of supplementation. Blood was analyzed for glucose, insulin, insulin resistance, β-cell function, and insulin sensitivity, PYY, GLP-1, GLP-2 and GIP. Urine samples were tested for molybdenum concentration. The results showed that consumption of lettuce biofortified with molybdenum for 12 days did not affect beta cell function but significantly reduced fasting glucose, insulin, insulin resistance and increased insulin sensitivity in healthy people. Consumption of biofortified lettuce did not show any modification in urine concentration of molybdenum among the groups. These data suggest that consumption of lettuce biofortified with molybdenum improves glucose homeostasis and PYY and GIP are involved in the action mechanism.