Background/Aims: The purpose of this study was to investigate the association between MTNR1A and MTNR1B gene polymorphisms and gestational diabetes mellitus (GDM) in Han Chinese women. Methods: Study participants included 350 patients with GDM and 480 control subjects. Three single-nucleotide polymorphisms (SNPs; rs2119882 in MTNR1A and rs10830963 and rs10830962 in MTNR1B) were genotyped using direct sequencing. Genotype and allele distributions of SNPs in cases of GDM and controls were analyzed. Association of the MTNR1A and MTNR1B gene variants with plasma glucose and insulin levels as well as blood lipid levels was further investigated. Results: The frequencies of genotypes and allele types of rs2119882 in MTNR1A and rs10830963 in MTNR1B were significantly different between women with GDM and controls (p < 0.05). Moreover, in the GDM group, these SNPs were associated with increased fasting plasma glucose concentrations (p < 0.001) and increased homeostasis model assessment of insulin resistance (p < 0.001). The rs10830962 polymorphism in MTNR1B was not associated with an increased risk of developing GDM or any of the clinical or metabolic characteristics in patients with GDM (p > 0.05). Conclusion: The genetic polymorphisms rs2119882 in MTNR1A and rs10830963 in MTNR1B are associated with an increased risk of developing GDM and insulin resistance in Han Chinese women.

The genetic polymorphism rs10830963 in MTNR1B and its protein expression levels in placenta are associated with an increased risk of developing GDM. Furthermore, rs10830963 may tag a molecular mechanism leading to insulin resistance in Han Chinese women with GDM.

Objective: The purpose of the study was to investigate the association between macrophage migration inhibitory factor (MIF) gene polymorphisms and gestational diabetes mellitus (GDM) in Han Chinese women. Methods: In this study, 915 unrelated pregnant women were recruited, among whom 430 had GDM and 485 served as controls. The rs755622 in the MIF gene (MIF-173G/C) was detected by the polymerase chain reaction Tm-shift genotyping method with fluorescence melting curve analysis. The associations of rs755622 in MIF variants with plasma glucose and insulin levels in the oral glucose tolerance test (OGTT) as well as with with blood fat levels were investigated. Results: The frequencies of genotypes and allele types of rs755622 in MIF were significantly different between women of the GDM and control groups (all p < 0.001). Moreover, the single nucleotide polymorphism (SNP) was significantly associated with increased glucose levels at 0, 60 and 120 min during the OGTT (all p < 0.0038) and with the increased homeostasis model assessment of insulin resistance (p < 0.001) in the GDM group. Conclusion: Genetic polymorphism of rs755622 in MIF is associated with increased risk of GDM and insulin resistance in Han Chinese women.

<b><i>Background:</i></b>The estrogen receptor α (ERα) gene is a potential candidate gene of gestational diabetes mellitus (GDM). <b><i>Objectives:</i></b> The purpose of the study was to investigate the relationship of ERα gene polymorphism (single nucleotide polymorphism [SNP]) and its expression in placental tissues with the development of GDM. <b><i>Methods:</i></b> The SNPs of PvuII and Xba I in the ERα gene of 175 pregnant women with GDM and 240 healthy pregnant women were detected by polymerase chain reaction-restriction fragment length polymorphism. Immunohistochemistry and western blotting were used to analyze the expression of the ERα gene in placental tissues. <b><i>Results:</i></b> The results showed that the frequency of the CC + CT genotype and the C allele frequency of PvuII in the GDM group was significantly higher than that of the control group (<i>p</i> &#x3c; 0.05). There was no significant difference in the genotype distribution and allele frequency of Xba I between the GDM group and control group. The expression of ERα in placental tissues of pregnant women with GDM was higher than that in the control group (<i>p</i> &#x3c; 0.05). The participants with the PvuII CC + CT genotype had elevated levels of fasting blood glucose, homeostasis model assessment of insulin resistance (IR), and ERα expression in placental tissues compared with those with the TT genotype in the GDM group (<i>p</i> &#x3c; 0.05). The SNP of Xba I of ERα gene had no correlation with clinical biochemical indicators of GDM and the expression of ERα in placental tissues (<i>p</i> &#x3e; 0.05). <b><i>Conclusions:</i></b> This study suggested that SNP of the ERα gene and abnormal expression of ERα in placenta tissues were associated with GDM. The C allele of PvuII may be associated with GDM. In addition, SNP of the PvuII site in pregnant women with GDM was related to the degree of IR and to the upregulation of ERα expression in placental tissues, which may play an important role in the pathogenesis of GDM.

The MIF-173G/C polymorphism is associated with PCOS in Chinese Han women and may contribute to the phenotypic expression of PCOS.