The association of circulating adiponectin and + 45 T/G polymorphism of adiponectin gene with gestational diabetes mellitus in Iranian population

Mechanisms and Physiological Roles of Polymorphisms in Gestational Diabetes Mellitus

Gestational diabetes mellitus (GDM) is a significant pregnancy complication linked to perinatal complications and an elevated risk of future metabolic disorders for both mothers and their children. GDM is diagnosed when women without prior diabetes develop chronic hyperglycemia due to β-cell dysfunction during gestation. Global research focuses on the association between GDM and single nucleotide polymorphisms (SNPs) and aims to enhance our understanding of GDM's pathogenesis, predict its risk, and guide patient management. This review offers a summary of various SNPs linked to a heightened risk of GDM and explores their biological mechanisms within the tissues implicated in the development of the condition.

Gestational diabetes mellitus: genetic factors, epigenetic alterations, and microbial composition

Gestational diabetes mellitus (GDM) is a common metabolic disorder, usually diagnosed during the third trimester of pregnancy that usually disappears after delivery. In GDM, the excess of glucose, fatty acids, and amino acids results in foetuses large for gestational age. Hyperglycaemia and insulin resistance accelerate the metabolism, raising the oxygen demand, and creating chronic hypoxia and inflammation. Women who experienced GDM and their offspring are at risk of developing type-2 diabetes, obesity, and other metabolic or cardiovascular conditions later in life. Genetic factors may predispose the development of GDM; however, they do not account for all GDM cases; lifestyle and diet also play important roles in GDM development by modulating epigenetic signatures and the body's microbial composition; therefore, this is a condition with a complex, multifactorial aetiology. In this context, we revised published reports describing GDM-associated single-nucleotide polymorphisms (SNPs), DNA methylation and microRNA expression in different tissues (such as placenta, umbilical cord, adipose tissue, and peripheral blood), and microbial composition in the gut, oral cavity, and vagina from pregnant women with GDM, as well as the bacterial composition of the offspring. Altogether, these reports indicate that a number of SNPs are associated to GDM phenotypes and may predispose the development of the disease. However, extrinsic factors (lifestyle, nutrition) modulate, through epigenetic mechanisms, the risk of developing the disease, and some association exists between the microbial composition with GDM in an organ-specific manner. Genes, epigenetic signatures, and microbiota could be transferred to the offspring, increasing the possibility of developing chronic degenerative conditions through postnatal life.

ADIPOQ gene (T45G and G276T) single nucleotide polymorphisms and their association with gestational diabetes mellitus in a Filipino population

Several studies have associated the presence of ADIPOQ gene polymorphisms with insulin resistance, adiponectin levels, and metabolic diseases such as diabetes, although with varying degrees of correlation depending on ethnicity. Here we aim to identify individual's susceptibility to gestational diabetes mellitus (GDM) in the presence of T45G and G276T single nucleotide polymorphisms (SNPs) within the ADIPOQ gene among Filipino pregnant women. A total of 285 pregnant women (95 GDM cases and 190 controls) were included in this study. Two ADIPOQ gene polymorphisms were genotyped using TaqMan assay. Results of SNP genotyping showed no significant differences in the frequencies of TT, TG and GG genotypes of T45G SNP between the GDM and control group [p = 1.0000, 0.6179, 0.5797; OR (95%CI) = 1.030 (0.582-1.874), 1.135 (0.683-1.828), 0.833 (0.481-1.420)]. Similarly, the frequencies of GG, GT, and TT genotypes of G276T SNP were comparable in both groups [p = 0.8002, 1.0000, 0.3466; OR (95%CI) = 1.090 (0.654-1.785), 1.022 (0.616-1.665), 0.433 (0.092-1.698)]. Moreover, although adiponectin levels were significantly decreased in GDM group (p = 0.0196) and have shown substantial negative correlations with FBS, 1-hour OGTT, 2-hour OGTT, and HOMA-IR (p < 0.05), they were not significantly different according to genotypes of T45G and G276T polymorphisms both in GDM and control group. Our results suggest that neither of the two ADIPOQ gene polymorphisms influence adiponectin levels and development of GDM in a Filipino population.

Association between the triglyceride to high-density lipoprotein cholesterol ratio and the risk of gestational diabetes mellitus: a second analysis based on data from a prospective cohort study

Background

Although there is strong evidence linking triglyceride to high-density lipoprotein cholesterol (TG/HDL-C) ratio to insulin resistance and diabetes mellitus, its clinical importance in pregnant women has not been well determined. This study sought to determine the connection between the TG/HDL-C ratio in the first trimester and the eventual onset of gestational diabetes mellitus (GDM).

Methods

We performed a secondary analysis of open-access data from a prospective cohort study. This present study included 590 singleton pregnant women at 10-14 weeks who visited the outpatient clinics for prenatal checks and were recorded at Incheon Seoul Women's Hospital and Seoul Metropolitan Government Seoul National University Boramae Medical Center in Korea. A binary logistic regression model, a series of sensitivity analyses, and subgroup analysis were used to examine the relationship between TG/HDL-C ratio and incident GDM. A receiver operating characteristic (ROC) analysis was also conducted to assess the ability of the TG/HDL-C ratio to predict GDM.

Results

The mean age of the included individuals was 32.06 ± 3.80 years old. The mean TG/HDL-C ratio was 1.96 ± 1.09. The incidence rate of GDM was 6.27%. After adjustment for potentially confounding variables, TG/HDL-C ratio was positively associated with incident GDM (OR=1.77, 95%CI: 1.32-2.38, P=0.0001). Sensitivity analyses and subgroup analysis demonstrated the validity of the relationship between the TG/HDL-C ratio and GDM. The TG/HDL-C ratio was a good predictor of GDM, with an area under the ROC curve of 0.7863 (95% CI: 0.7090-0.8637). The optimal TG/HDL-C ratio cut-off value for detecting GDM was 2.2684, with a sensitivity of 72.97% and specificity of 75.05%.

Conclusion

Our results demonstrate that the elevated TG/HDL-C ratio is related to incident GDM. The TG/HDL-C ratio at 10-14 weeks could help identify pregnant women at risk for GDM and may make it possible for them to receive early and effective treatment to improve their prognosis.

Dissecting the Molecular Role of ADIPOQ SNPs in Saudi Women Diagnosed with Gestational Diabetes Mellitus

The traditional definition of gestational diabetes mellitus (GDM) is the leading cause of carbohydrate intolerance in hyperglycemia of varying severity, with onset or initial detection during pregnancy. Previous studies have reported a relationship among obesity, adiponectin (ADIPOQ), and diabetes in Saudi Arabia. ADIPOQ is an adipokine that is produced and secreted by adipose tissue involved in the regulation of carbohydrate and fatty acid metabolism. This study investigated the molecular association between rs1501299, rs17846866, and rs2241766 single-nucleotide polymorphisms (SNPs) in ADIPOQ and GDM in Saudi Arabia. Patients with GDM and control patients were selected, and serum and molecular analyses were performed. Statistical analyses were performed on clinical data, Hardy Weinberg Equilibrium, genotype and allele frequencies, multiple logistic regression, ANOVA, haplotype, linkage disequilibrium, as well as MDR and GMDR analyses. The clinical data showed significant differences in various parameters between the GDM and non-GDM groups (p < 0.05). In GDM women with alleles, genotypes, and different genetic models, the rs1501299 and rs2241766 SNPs showed a strong association (p < 0.05). Multiple logistic regression analysis revealed a negative correlation (p > 0.05). This study concluded that rs1501299 and rs2241766 SNPs were strongly associated with GDM in women in Saudi Arabia.

Molecular biomarkers for gestational diabetes mellitus and postpartum diabetes

ABSTRACT

Gestational diabetes mellitus (GDM) is a growing public health problem worldwide that threatens both maternal and fetal health. Identifying individuals at high risk for GDM and diabetes after GDM is particularly useful for early intervention and prevention of disease progression. In the last decades, a number of studies have used metabolomics, genomics, and proteomic approaches to investigate associations between biomolecules and GDM progression. These studies clearly demonstrate that various biomarkers reflect pathological changes in GDM. The established markers have potential use as screening and diagnostic tools in GDM and in postpartum diabetes research. In the present review, we summarize recent studies of metabolites, single-nucleotide polymorphisms, microRNAs, and proteins associated with GDM and its transition to postpartum diabetes, with a focus on their predictive value in screening and diagnosis.

Pathophysiological Role of Genetic Factors Associated With Gestational Diabetes Mellitus

Gestational Diabetes Mellitus (GDM) is a highly prevalent maternal pathology characterized by maternal glucose intolerance during pregnancy that is, associated with severe complications for both mother and offspring. Several risk factors have been related to GDM; one of the most important among them is genetic predisposition. Numerous single nucleotide polymorphisms (SNPs) in genes that act at different levels on various tissues, could cause changes in the expression levels and activity of proteins, which result in glucose and insulin metabolism dysfunction. In this review, we describe various SNPs; which according to literature, increase the risk of developing GDM. These SNPs include: (1) those associated with transcription factors that regulate insulin production and excretion, such as rs7903146 (TCF7L2) and rs5015480 (HHEX); (2) others that cause a decrease in protective hormones against insulin resistance such as rs2241766 (ADIPOQ) and rs6257 (SHBG); (3) SNPs that cause modifications in membrane proteins, generating dysfunction in insulin signaling or cell transport in the case of rs5443 (GNB3) and rs2237892 (KCNQ1); (4) those associated with enzymes such as rs225014 (DIO2) and rs9939609 (FTO) which cause an impaired metabolism, resulting in an insulin resistance state; and (5) other polymorphisms, those are associated with growth factors such as rs2146323 (VEGFA) and rs755622 (MIF) which could cause changes in the expression levels of these proteins, producing endothelial dysfunction and an increase of pro-inflammatory cytokines, characteristic on GDM. While the pathophysiological mechanism is unclear, this review describes various potential effects of these polymorphisms on the predisposition to develop GDM.

Single-nucleotide polymorphisms as important risk factors of diabetes among Middle East population

Diabetes is a chronic metabolic disorder that leads to the dysfunction of various tissues and organs, including eyes, kidneys, and cardiovascular system. According to the World Health Organization, diabetes prevalence is 8.8% globally among whom about 90% of cases are type 2 diabetes. There are not any significant clinical manifestations in the primary stages of diabetes. Therefore, screening can be an efficient way to reduce the diabetic complications. Over the recent decades, the prevalence of diabetes has increased alarmingly among the Middle East population, which has imposed exorbitant costs on the health care system in this region. Given that the genetic changes are among the important risk factors associated with predisposing people to diabetes, we examined the role of single-nucleotide polymorphisms (SNPs) in the pathogenesis of diabetes among Middle East population. In the present review, we assessed the molecular pathology of diabetes in the Middle East population that paves the way for introducing an efficient SNP-based diagnostic panel for diabetes screening among the Middle East population. Since, the Middle East has a population of 370 million people; the current review can be a reliable model for the introduction of SNP-based diagnostic panels in other populations and countries around the world.

Magnesium supplementation for glycemic status in women with gestational diabetes: a systematic review and meta-analysis

OBJECTIVE

The effect of magnesium supplementation on glycemic status in women with gestational diabetes remains controversial and this meta-analysis aims to explore the efficacy of magnesium supplementation for gestational diabetes.

METHODS

We have searched PubMed, Excerpta Medica database, Web of science, Elton B. Stephens. Company, and Cochrane library databases. The meta-analysis included randomized controlled trials (RCTs) assessing the effect of magnesium supplementation for gestational diabetes and was performed using the random-effect model.

RESULTS

Four RCTs were included in the meta-analysis. Overall, compared with placebo in gestational diabetes, magnesium supplementation was associated with significantly reduced fasting plasma glucose (standard mean difference [SMD] = -0.99; 95% confidence interval [CI] = -1.28 to -0.70; p < .00001), serum insulin (SMD = -0.75; 95% CI = -1.24 to -0.26; p = .003), homeostasis model assessment of insulin resistance (SMD = -0.74; 95% CI = -1.10 to -0.39; p < .0001) and increased quantitative insulin sensitivity check index (SMD = 0.47; 95% CI = 0.12 to 0.82; p = .008). In addition, low-density lipoprotein-cholesterol (SMD = -0.39; 95% CI = -0.73 to -0.04; p = .03) and total cholesterol (SMD = -0.62; 95% CI = -0.97 to -0.27; p = .0005) were also obviously decreased in the magnesium group than those in the control group.

CONCLUSION

Magnesium supplementation benefits glycemic control for gestational diabetes.

The implications of the purinergic signaling throughout pregnancy

Purinergic signaling is a necessary mechanism to trigger or even amplify cell communication. Its ligands, notably adenosine triphosphate (ATP) and adenosine, modulate specific membrane-bound receptors in virtually all human cells. Regardless of the stage of the pregnancy, cellular communication between maternal, placental, and fetal cells is the paramount mechanism to sustain its optimal status. In this review, we describe the crucial role of purinergic signaling on the regulation of the maternal-fetal trophic exchanges, immune control, and endocrine exchanges throughout pregnancy. The nature of the modulation of both ATP and adenosine on the embryo-maternal interface, going through placental invasion until birth delivery depends on the general maternal-fetal health state and consequently on the selective activation of their specific receptors. In addition, an increasing number of studies have been demonstrating the pivotal role of ATP and adenosine in modulating deleterious effects of suboptimal conditions of pregnancy. Here, we discuss the role of purinergic signaling on the balance that coordinates the embryo-maternal exchanges and a promising therapeutic venue in the context of pregnancy disorders.

Adiponectin gene polymorphisms associated with diabetes mellitus: A descriptive review

Diabetes is currently a growing concern of the age. Prevention and treatment of diabetes is a global health priority. Adiponectin is an adipocyte derived protein hormone that enhances insulin sensitivity and ameliorates diabetes by enhancing fatty acid oxidation and glucose uptake in skeletal muscle and reducing glucose production in the liver. Low serum adiponectin concentrations are associated with diabetes, central obesity, insulin resistance and metabolic syndrome. Adiponectin gene is located on chromosome 3q27, where a locus of susceptibility to diabetes was mapped. Several cross-sectional studies showed that single nucleotide polymorphisms (SNPs) in adiponectin gene (ADIPOQ) were associated with diabetes. SNPs in ADIPOQ help in assessing the association of common variants with levels of adiponectin and the risk of diabetes. Two common SNPs, rs2241766 and rs1501299, have been linked significantly to type 1 diabetes mellitus which endow the world with a block of haplotypes. Experimental evidences also suggest that rs1501299, rs2241766, rs266729, rs17366743, rs17300539, rs182052, rs822396, rs17846866, rs3774261 and rs822393 are significantly associated with type 2 diabetes mellitus which is the predominant form of the disease. In addition, rs2241766 and rs266729 are extensively associated with gestational diabetes, a condition that develops in women during pregnancy. Therefore not a particular single mutation but a number of SNPs in adiponectin gene could be a risk factor for developing diabetes among the individuals worldwide. This study firmly suggests that adiponectin plays a crucial role in the pathogenesis of type 1, type 2 and gestational diabetes mellitus.

Update on the genetic and epigenetic etiology of gestational diabetes mellitus: a review

Background

Many studies have been conducted on the genetic and epigenetic etiology of gestational diabetes mellitus (GDM) in the last two decades because of the disease’s increasing prevalence and role in global diabetes mellitus (DM) explosion. An update on the genetic and epigenetic etiology of GDM then becomes imperative to better understand and stem the rising incidence of the disease. This review, therefore, articulated GDM candidate genes and their pathophysiology for the awareness of stakeholders.

Main body (genetic and epigenetic etiology, GDM)

The search discovered 83 GDM candidate genes, of which TCF7L2, MTNR1B, CDKAL1, IRS1, and KCNQ1 are the most prevalent. Certain polymorphisms of these genes can modulate beta-cell dysfunction, adiposity, obesity, and insulin resistance through several mechanisms. Environmental triggers such as diets, pollutants, and microbes may also cause epigenetic changes in these genes, resulting in a loss of insulin-boosting and glucose metabolism functions. Early detection and adequate management may resolve the condition after delivery; otherwise, it will progress to maternal type 2 diabetes mellitus (T2DM) and fetal configuration to future obesity and DM. This shows that GDM is a strong risk factor for T2DM and, in rare cases, type 1 diabetes mellitus (T1DM) and maturity-onset diabetes of the young (MODY). This further shows that GDM significantly contributes to the rising incidence and burden of DM worldwide and its prevention may reverse the trend.

Conclusion

Mutations and epigenetic changes in certain genes are strong risk factors for GDM. For affected individuals with such etiologies, medical practitioners should formulate drugs and treatment procedures that target these genes and their pathophysiology.

Whether the risk of gestational diabetes mellitus is affected by TNF-α, IL-6, IL-10 or ADIPOQ polymorphisms: a meta-analysis

BACKGROUND

Whether polymorphisms in tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-10 (IL-10) or adiponectin (ADIPOQ) influence the risk of gestational diabetes mellitus (GDM) or not remain inconclusive. Therefore, the authors conducted a meta-analysis to robustly assess relationships between polymorphisms in TNF-α, IL-6, IL-10 or ADIPOQ and the risk of GDM by merging the results of eligible publications.

METHODS

A through literature searching in Medline, Embase, Wanfang, VIP and CNKI was conducted by the authors to identify eligible publications, and twenty-two publications were finally found to be eligible for merged quantitative analyses.

RESULTS

The merged quantitative analyses revealed that ADIPOQ + 45T/G (rs2241766) polymorphism was significantly associated with the risk of GDM in overall population (dominant comparison: OR = 0.70, p < 0.001; recessive comparison: OR = 1.95, p < 0.001; over-dominant comparison: OR = 1.18, p = 0.03; allele comparison: OR = 0.71, p < 0.001) and Asians (dominant comparison: OR = 0.70, p < 0.001; recessive comparison: OR = 1.94, p < 0.001; allele comparison: OR = 0.72, p < 0.001). Nevertheless, we did not observe any positive results for TNF-α - 238G/A (rs361525), TNF-α - 308G/A (rs1800629), IL6 - 174G/C (rs1800795), IL-10 - 819C/T (rs1800871), IL-10 - 592C/A (rs1800872), IL-10 - 1082A/G (rs1800896) and ADIPOQ + 276G/T (rs1501299) polymorphisms.

CONCLUSIONS

The present meta-analysis shows that among investigated TNF-α, IL-6, IL-10 or ADIPOQ polymorphisms, only ADIPOQ + 45T/G (rs2241766) polymorphism may affect the risk of GDM.

Erythrocyte glucose-6-phosphate dehydrogenase activity and risk of gestational diabetes

Purpose

Glucose-6-phosphate dehydrogenase (G6PD) is the regulating enzyme in the pentose phosphate pathway. A link between the activity of G6PD and diabetes mellitus has previously been reported. The association of G6PD activity with the pathogenesis of gestational diabetes mellitus (GDM) has not yet been investigated. The aim of the present study was to investigate the association of erythrocyte G6PD activity with major characteristics of GDM.

Methods

This case-control study was conducted at Hafez Hospital, Shiraz University of Medical Sciences, Shiraz, Iran from March to November 2017. Eighty-four age-matched pregnant women including GDM (n = 33), impaired glucose tolerance (IGT; n = 7), and normal glucose tolerance (NGT; n = 44) subjects were enrolled in this study. The levels of erythrocyte G6PD activity, fasting plasma glucose (FPG), insulin, malondialdehyde (MDA), and ferric reducing power (FRAP) of serum were measured. The level of homeostasis model for the assessment of insulin resistance (HOMA-IR) was calculated. The data were analyzed using SPSS software. P < 0.05 was considered statistically significant.

Results

The values of FPG, insulin, HOMA-IR, G6PD activity, and FRAP were significantly higher in GDM patients compared to NGT subjects. G6PD activity was correlated with FPG ((r = 0.224; P = 0.041). Binary logistic regression analysis revealed independent association of body mass index >25.88 [OR = 3.23, 95% CI 1.071-9.75, P = 0.037], HOMA- IR >2.33 [OR = 7.15, 95% CI 2.26-22.56, P < 0.001], and G6PD activity>21.17 U/g Hb [OR = 4.63, 95% CI 1.49-14.38, P = 0.008] with an increased risk of GDM. No significant change was observed among serum MDA levels in the three groups.

Conclusion

The findings demonstrate that increased G6PD activity is positively associated with the risk of GDM.

Mechanisms of Adiponectin Action in Fertility: An Overview from Gametogenesis to Gestation in Humans and Animal Models in Normal and Pathological Conditions

Adiponectin is the most abundant plasma adipokine. It mainly derives from white adipose tissue and plays a key role in the control of energy metabolism thanks to its insulin-sensitising, anti-inflammatory, and antiatherogenic properties. In vitro and in vivo evidence shows that adiponectin could also be one of the hormones controlling the interaction between energy balance and fertility in several species, including humans. Indeed, its two receptors—AdipoR1 and AdipoR2—are expressed in hypothalamic–pituitary–gonadal axis and their activation regulates Kiss, GnRH and gonadotropin expression and/or secretion. In male gonads, adiponectin modulates several functions of both somatic and germ cells, such as steroidogenesis, proliferation, apoptosis, and oxidative stress. In females, it controls steroidogenesis of ovarian granulosa and theca cells, oocyte maturation, and embryo development. Adiponectin receptors were also found in placental and endometrial cells, suggesting that this adipokine might play a crucial role in embryo implantation, trophoblast invasion and foetal growth. The aim of this review is to characterise adiponectin expression and its mechanism of action in male and female reproductive tract. Further, since features of metabolic syndrome are associated with some reproductive diseases, such as polycystic ovary syndrome, gestational diabetes mellitus, preeclampsia, endometriosis, foetal growth restriction and ovarian and endometrial cancers, evidence regarding the emerging role of adiponectin in these disorders is also discussed.

Adiponectin gene polymorphisms and risk of gestational diabetes mellitus: A meta-analysis

BACKGROUND

Adiponectin (ADIPOQ) is an important factor involved in the regulation of both carbohydrate and lipid metabolism. Polymorphisms in the ADIPOQ gene are known to influence an individual’s predisposition to metabolic syndrome and type 2 diabetes. Moreover, women with gestational diabetes mellitus (GDM) are at an increased risk of developing type 2 diabetes. Several studies have been conducted previously to assess the association between ADIPOQ polymorphisms and GDM; however, the results of the association are inconclusive.

AIM

To quantitatively evaluate the association between ADIPOQ +45T/G, +276G/T, and -11377C/G polymorphisms and the risk of GDM.

METHODS

A systematic search of EMBASE, PubMed, CNKI, Web of Science, and WANFANG DATA was conducted up to October 20, 2018. We calculated merged odds ratios (ORs) with 95% confidence intervals (CIs) using a fixed-effects or random-effects model depending on the between-study heterogeneity to evaluate the association between AIDPOQ +45T/G, +276G/T, and -11377C/G polymorphisms and the risk of GDM. Subgroup analysis was performed by ethnicity. Publication and sensitivity bias analyses were performed to test the robustness of the association. All statistical analyses were conducted using Stata12.0.

RESULTS

Nine studies of +45T/G included 1024 GDM cases and 1059 controls, five studies of +276G/T included 590 GDM cases and 595 controls, and five studies of -11377C/G included 722 GDM cases and 791 controls. Pooled ORs indicated that +45T/G increased GDM risk in Asians (allelic model: OR = 1.47, 95%CI: 1.27-1.70, P = 0.000; dominant model: OR = 1.54, 95%CI: 1.27-1.85, P = 0.000; recessive model: OR=2.00, 95%CI: 1.43-2.85, P = 0.000), not in South Americans (allelic model: OR = 1.21, 95%CI: 0.68-2.41, P = 0.510; dominant model: OR = 1.13, 95%CI: 0.59-2.15, P = 0.710; recessive model: OR = 2.18, 95%CI: 0.43-11.07, P = 0.350). There were no significant associations between +276G/T (allelic model: OR = 0.88, 95%CI: 0.74-1.05, P = 0.158; dominant model: OR = 0.91, 95%CI: 0.65-1.26, P = 0.561; recessive model: OR = 0.82, 95%CI: 0.64-1.05, P = 0.118) or -11377C/G (allelic model: OR = 0.96, 95%CI: 0.72-1.26, P = 0.750; dominant model: OR = 1.00, 95%CI: 0.73-1.37, P = 0.980; recessive model: OR = 0.90, 95%CI: 0.61-1.32, P = 0.570) and the risk of GDM.

CONCLUSION

Our meta-analysis shows the critical role of the ADIPOQ +45T/G polymorphism in GDM, especially in Asians. Studies focused on delineating ethnicity-specific factors with larger sample sizes are needed.

Molecular Biomarkers for Gestational Diabetes Mellitus

Gestational diabetes mellitus (GDM) is a growing public health problem worldwide. The condition is associated with perinatal complications and an increased risk for future metabolic disease in both mothers and their offspring. In recent years, molecular biomarkers received considerable interest as screening tools for GDM. The purpose of this review is to provide an overview of the current status of single-nucleotide polymorphisms (SNPs), DNA methylation, and microRNAs as biomarkers for GDM. PubMed, Scopus, and Web of Science were searched for articles published between January 1990 and August 2018. The search terms included “gestational diabetes mellitus”, “blood”, “single-nucleotide polymorphism (SNP)”, “DNA methylation”, and “microRNAs”, including corresponding synonyms and associated terms for each word. This review updates current knowledge of the candidacy of these molecular biomarkers for GDM with recommendations for future research avenues.

The effects of magnesium and vitamin E co-supplementation on parameters of glucose homeostasis and lipid profiles in patients with gestational diabetes

BACKGROUND

Magnesium and vitamin E are known to exert multiple beneficial effects, such as anti-glycemic and anti-lipidemic properties. The aim of this study was to determine the effects of magnesium and vitamin E co-supplementation on metabolic status of women with gestational diabetes (GDM).

METHODS

This randomized, double-blinded, placebo-controlled trial was conducted among 60 subjects diagnosed with GDM, aged 18-40 years. Subjects were randomly allocated into two groups to receive 250 mg/day magnesium oxide plus 400 IU/day vitamin E supplements or placebo (n = 30 each group) for 6 weeks. Participants' blood samples were taken to determine their metabolic profiles.

RESULTS

Subjects who received magnesium plus vitamin E supplements had significantly lower fasting plasma glucose (β - 5.20 mg/dL; 95% CI, - 7.88, - 2.52; P = 0.002), serum insulin levels (β - 2.93 μIU/mL; 95% CI, - 5.68, - 0.18; P = 0.02) and homeostasis model of assessment-insulin resistance (β - 0.78; 95% CI, - 1.42, - 0.14; P = 0.01), and higher quantitative insulin sensitivity check index (β 0.01; 95% CI, 0.005, 0.02; P = 0.002) compared with placebo. In addition, magnesium plus vitamin E supplementation resulted in a significant reduction in serum triglycerides (β - 50.31 mg/dL; 95% CI, - 67.58, - 33.04; P < 0.001), VLDL- (β - 10.06 mg/dL; 95% CI, - 13.51, - 6.60; P < 0.001), total- (β - 26.10 mg/dL; 95% CI, - 41.88, - 10.33; P = 0.004), LDL- (β - 15.20 mg/dL; 95% CI, - 29.50, - 0.91; P = 0.03) and total-/HDL-cholesterol ratio (β - 0.46; 95% CI, - 0.72, - 0.19; P < 0.001) compared with placebo. Magnesium and vitamin E co-supplementation did not affect HDL-cholesterol levels.

CONCLUSIONS

Overall, magnesium and vitamin E co-supplementation for 6 weeks in women with GDM significantly improved glycemic control and lipid profiles, except for HDL-cholesterol levels.

CLINICAL TRIAL REGISTRATION NUMBER

http://www.irct.ir : IRCT20170513033941N24.

Tumor necrosis factor- α, adiponectin and their ratio in gestational diabetes mellitus

Background:

It has been suggested that inflammation might be implicated in the gestational diabetes mellitus (GDM) complications, including insulin resistance. The aims of the current study were to explore maternal circulating values of TNF-α, adiponectin and the adiponectin/TNF-α ratio in women with GDM compared with normal pregnancy and their relationships with metabolic syndrome biomarkers.

Methods:

Forty women with GDM and 40 normal pregnant women were included in the study. Commercially available enzyme-linked immunosorbent assay methods were used to measure serum levels of TNF-α and total adiponectin.

Results:

Women with GDM had higher values of TNF-α (225.08±27.35 vs 115.68±12.64 pg/ml, p<0.001) and lower values of adiponectin (4.50±0.38 vs 6.37±0.59 µg/ml, p=0.003) and the adiponectin/TNF-α ratio (4.31±0.05 vs 4.80±0.07, P<0.001) than normal pregnant women. The adiponectin/TNF-α ratio showed negative correlations with insulin resistance (r=-0.68, p<0.001) and triglyceride (r=-0.39, p=0.014) and a positive correlation with insulin sensitivity (r=0.69, p<0.001). Multiple linear regression analysis showed that values of the adiponectin /TNF-α ratio were independently associated with insulin resistance. Binary logistic regression analysis showed that GDM was negatively associated with adiponectin /TNF-α ratio.

Conclusions:

In summary, the adiponectin/TNF-α ratio decreased significantly in GDM compared with normal pregnancy. The ratio might be an informative biomarker for assessment of pregnant women at high risk of insulin resistance and dyslipidemia and for diagnosis and therapeutic monitoring aims in GDM.

Adiponectin and leptin gene polymorphisms in women with gestational diabetes mellitus

PURPOSE

Gestational diabetes mellitus (GDM) is the glucose intolerance occurring during pregnancy. The prevalence of GDM is increased in obese women. Leptin and adiponectin are adipokines that play an important role in the regulation of insulin secretion and glucose and lipid metabolism. The aim of this study was to examine the association between adiponectin and leptin gene polymorphisms and the development of GDM.

METHODS

This case-control study included 204 pregnant women with GDM and 207 pregnant women with normal glucose tolerance (NGT). The diagnosis of GDM was based on a 75-g oral glucose tolerance test (OGTT) at 24-28 weeks' gestation. To discriminate the ADIPOQ rs266729, rs1501299 and LEP rs2167270 alleles, TaqMan® Pre-Designed SNP Genotyping Assays were used.

RESULTS

There was a statistically significant association between the ADIPOQ rs266729 gene polymorphism and GDM. Among women with GDM, a higher prevalence of the G allele was observed (GG and CG genotypes). Multivariate logistic regression analysis, taking into account age, BMI before pregnancy, past pregnancies and the ADIPOQ rs266729 gene polymorphism, revealed that the presence of a G allele is an independent risk factor for GDM. Moreover, there was the association between the LEP rs2167270 polymorphism and the requirement for daily insulin, which was significantly higher in women with the A allele (AA and GA genotypes).

CONCLUSIONS

The results of our study suggest an association between adiponectin gene rs266729 as well as leptin gene rs2167270 polymorphisms and GDM.

No association of adiponectin +45 T/G polymorphism with the risk of gestational diabetes mellitus: Evidence from a meta-analysis

Introduction:

Adiponectin (ADIPOQ), involved in regulating glucose levels and fatty acid oxidation, plays key roles in metabolic derangements such as gestational diabetes mellitus (GDM). Previously, several studies have been conducted to assess the association between ADIPOQ +45 T/G polymorphism and risk of GDM. The results, however, are inconclusive. We aimed to evaluate the effect of the polymorphism on the risk of GDM using a meta-analysis.

Materials and methods:

After databases searching, eight records were identified. Pooled odds ratios (ORs) with their corresponding 95% confidence intervals (CIs) were used to evaluate the association between ADIPOQ +45 T/G polymorphism and risk of GDM.

Results:

No significant association was observed between the ADIPOQ +45 T/G polymorphism and the risk of GDM (heterozygote comparison: OR = 1.15, 95% CI, 0.70–1.89; homozygote comparison: OR = 1.21, 95% CI, 0.48–3.03; dominant model: OR = 0.86, 95% CI, 0.50–1.48, recessive model: OR = 1.21, 95% CI, 0.62–2.33, and allele comparison: OR = 1.17, 95% CI, 0.79–1.76, respectively). Apparent heterogeneity was detected. However, no evidence of publication bias was found.

Conclusions:

This meta-analysis provides evidence that the ADIPOQ +45 T/G polymorphism was not related to the risk of GDM. Further multicenter, prospective studies with larger sample size would be valuable to confirm the result.