The -30G>A polymorphism of the glucokinase gene promoter is associated with obesity in a population from southern Spain

Association of glucokinase gene and glucokinase regulatory protein gene polymorphisms with gestational diabetes mellitus: A case-control study

OBJECTIVES

The aim of this study was to investigate the association of glucokinase (GCK) gene, glucokinase regulatory protein (GCKR) gene polymorphisms with the susceptibility to GDM in Chinese population.

RESEARCH DESIGN AND METHODS

This case-control study included 835 GDM patients and 870 non-diabetic pregnant women who had their prenatal examinations at 24-28 gestational weeks at the Maternal and Child Health Hospital of Hubei Province from January 15, 2018 to March 31, 2019. The nurses were trained to collect clinical information and blood samples. The candidate single nucleotide polymorphism (SNPs, GCK rs1799884, rs4607517, rs10278336, rs2268574, rs730497 and GCKR rs780094, rs1260326) were genotyped on Sequenom Massarray platform. Statistical analysis including independent sample t test, chi-square test, logistic regression and one-way ANOVA were performed to evaluate the differences in allele and genotype distributions and their correlations with the odds of GDM.

RESULTS

There were statistically significant differences in age, pre-gestational BMI, education level and family history of diabetes between case and control group (P < 0.05). After adjusting for these confounders, GCK rs1799884 was still significantly associated with GDM (P < 0.05), but there were no significant associations between rs4607517, rs10278336 and rs2268574, rs780094 and rs1260326 polymorphisms and GDM odds (P > 0.05). In addition, the pregnant women with rs4607517 TT genotype had the significantly higher fasting blood glucose level than CC genotype (P < 0.05).

CONCLUSION

GCK rs1799884 mutation is associated with higher GDM odds in Chinese population. Further larger studies are needed to explore the association between GCK and GCKR polymorphisms and GDM susceptibility.

Haplotypes of the genes (GCK and G6PC2) underlying the glucose/glucose-6-phosphate cycle are associated with pancreatic beta cell glucose sensitivity in patients with newly diagnosed type 2 diabetes from the VNDS study (VNDS 11)

BACKGROUND

Elevated fasting plasma glucose has been associated with increased risk for development of type 2 diabetes (T2D). The balance between glucokinase (GCK) and glucose-6-phosphate catalytic subunit 2 (G6PC2) activity are involved in glucose homeostasis through glycolytic flux, and subsequent insulin secretion.

AIM

In this study, we evaluated the association between the genetic variability of G6PC2 and GCK genes and T2D-related quantitative traits.

METHODS

In 794 drug-naïve, GADA-negative, newly diagnosed T2D patients (VNDS; NTC01526720) we performed: genotyping of 6 independent tag-SNPs within GCK gene and 5 tag-SNPs within G6PC2 gene; euglycaemic insulin clamp to assess insulin sensitivity; OGTT to estimate beta-cell function (derivative and proportional control; DC, PC) by mathematical modeling. Genetic association analysis has been conducted using Plink software.

RESULTS

Two SNPs within GCK gene (rs882019 and rs1303722) were associated to DC in opposite way (both p < 0.004). Two G6PC2 variants (rs13387347 and rs560887) were associated to both parameters of insulin secretion (DC and PC) and to fasting C-peptide levels (all p < 0.038). Moreover, subjects carrying the A allele of rs560887 showed higher values of 2h-plasma glucose (2hPG) (p = 0.033). Haplotype analysis revealed that GCK (AACAAA) haplotype was associated to decreased fasting C-peptide levels, whereas, the most frequent haplotype of G6PC2 (GGAAG) was associated with higher fasting C-peptide levels (p = 0.001), higher PC (β = 6.87, p = 0.022) and the lower 2hPG (p = 0.012).

CONCLUSION

Our findings confirmed the role of GCK and G6PC2 in regulating the pulsatility in insulin secretion thereby influencing insulin-signaling and leading to a gradual modulation in glucose levels in Italian patients with newly diagnosed T2D.

Association of the glucokinase gene promoter polymorphism -30G > A (rs1799884) with gestational diabetes mellitus susceptibility: a case-control study and meta-analysis

PURPOSE

Several studies have examined the association between glucokinase (GCK)-30G > A polymorphism and gestational diabetes mellitus (GDM). However, the results are still controversial. We performed the case-control study to investigate whether GCK-30G > A polymorphism correlates with the susceptibility of GDM in Chinese populations, and then conducted a meta-analysis by combining the previous studies.

METHODS

We recruited 948 GDM patients and 975 controls from May 2011 to August 2013. All the subjects were genotyped using the PCR-based invader assay. The differences of allelic frequencies and genotype distributions between GDM patients and controls were investigated in case-control study. A systematic search of all relevant studies was conducted. The observational studies that were related to an association between the glucokinase (GCK)-30G > A polymorphism and GDM were identified. The association between the glucokinase (GCK)-30G > A polymorphism and GDM susceptibility was assessed using genetic models.

RESULTS

The case-control study showed that GCK-30G > A polymorphism was associated with the susceptibility of GDM in a Chinese population. Furthermore, other six previously reported studies were included to perform meta-analysis. The meta-analysis showed that GCK-30G > A polymorphism was associated with GDM in Caucasian and Asian.

CONCLUSIONS

This study suggested that GCK-30G > A polymorphism may be associated with the susceptibility of GDM in a Chinese population. The further meta-analysis provides additional evidence supporting the above result that the risk allele of the GCK-30G > A polymorphism may increase GDM risk.

Glucokinase gene promoter -30G>A polymorphism: a cross-sectional association study with obesity, diabetes Mellitus, hyperlipidemia, hypertension and metabolic syndrome in an Iranian hospital

OBJECTIVE: A -30G>A single nucleotide polymorphism in the promoter region of the glucokinase gene has been previously associated with obesity, insulin resistance and diabetes. The present study aimed to evaluate the association of this polymorphism with obesity and its comorbidities in a population from Northeast Iran. METHODS: Five hundred and forty-two subjects aged 18 to 65 years were included in the study and divided into normal (BMI<25, n=220), overweight (25<BMI<30, n=135) and obese (BMI>30, n=187) groups. All subjects were genotyped for the -30G>A polymorphism using the polymerase chain reaction-restriction fragment length polymorphism technique. RESULTS: The genotypes and allele frequencies of the three groups did not differ significantly (p>0.05). When the study population was categorized according to diabetes mellitus, hyperlipidemia, hypertension and metabolic syndrome status, no significant difference in -30G>A genotypes and alleles was found between the subgroups with and without these disorders (p>0.05), apart from a significantly higher frequency of the G allele in the hyperlipidemic vs. non-hyperlipidemic subgroup (p<0.05). CONCLUSION: The findings of the present study do not support an association between the -30G>A polymorphism and high body mass index in the Iranian population.

Association of GCKR rs780094, alone or in combination with GCK rs1799884, with type 2 diabetes and related traits in a Han Chinese population

AIMS/HYPOTHESIS

The GCKR rs780094 and GCK rs1799884 polymorphisms have been reported to be associated with dyslipidaemia and type 2 diabetes in white Europeans. The aim of this study was to replicate these associations in Han Chinese individuals and to identify the potential mechanisms underlying these associations.

METHODS

The single nucleotide polymorphisms rs780094 and rs1799884 were genotyped in a population-based sample of Han Chinese individuals (n = 3,210) and tested for association with risk of type 2 diabetes and related phenotypes.

RESULTS

The GCKR rs780094 A allele was marginally associated with reduced risk of type 2 diabetes (OR 0.85, 95% CI 0.73-1.00, p value under an additive model [p((add))] = 0.05) and significantly associated with reduced risk of impaired fasting glucose (IFG) or type 2 diabetes (OR 0.86, 95% CI 0.77-0.96, p([add]) = 0.0032). It was also significantly associated with decreased fasting glucose and increased HOMA of beta cell function (HOMA-B) and fasting triacylglycerol levels (p([add]) = 0.0169-5.3 x 10(-6)), but not with HOMA of insulin sensitivity (HOMA-S). The associations with type 2 diabetes and IFG remained significant after adjustment for BMI, while adjustment for HOMA-B abolished the associations. The GCKR rs780094 was also associated with obesity and BMI, independently of its association with type 2 diabetes. The GCK rs1799884 A allele was significantly associated with decreased HOMA-B (p([add]) = 0.0005), but not with type 2 diabetes or IFG. Individuals with increasing numbers of risk alleles for both variants had significantly lower HOMA-B (p([add]) = 5.8 x 10(-5)) in the combined analysis.

CONCLUSIONS/INTERPRETATION

Consistent with observations in white Europeans, the GCKR rs780094 polymorphism contributes to the risk of type 2 diabetes and dyslipidaemia in Han Chinese individuals. In addition, we showed that the effect on type 2 diabetes is probably mediated through impaired beta cell function rather than through obesity.