Association of XbaI GLUT1 Polymorphism with Susceptibility to Type 2 Diabetes Mellitus and Diabetic Nephropathy

Objectives: Diabetic nephropathy (DN) is one of the chronic microangiopathic complications of type 2 diabetes (T2DM) and has become the most frequent cause of end-stage renal disease. The XbaI polymorphism in the glucose transporter (GLUT1) has been suggested in the development of DN. We examined the association between XbaI polymorphism of GLUT1 and susceptibility to T2DM and development of DN. Methods: The study included 227 T2DM patients divided into 107 without DN (DM ? DN) and 120 with DN (DM + DN), in addition to 100 apparently healthy controls. Genotyping was done by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP). Results: The GLUT1 XbaI T allele was associated with increased susceptibility to T2DM, when comparing the healthy controls to the whole diabetic group, odds ratio (OR) = 1.899, 95% confidence interval (CI) (1.149 - 3.136), p = 0.011. This association was also significant between healthy controls and DM ? DN OR = 1.997 (1.079 - 3.699), p = 0.026 as well as between healthy controls and DM + DN OR = 1.818 (1.016 - 3.253), p = 0.042. However there was no significant association of XbaI polymorphism with DN when comparing DM ? DN to DM + DN OR = 0.910 (0.474 - 1.747), p = 0.777. Conclusion: XbaI T allele is associated with increased susceptibility to T2DM, but not to development of DN. Further studies are needed to replicate such findings.

The C161T Polymorphism in Peroxisome Proliferator-Activated Receptor ɣ2, but Not Pro12Ala, Is Associated with Diabetic Retinopathy in Type 2 Diabetes Mellitus in an Egyptian Population

Objectives: Diabetic retinopathy (DR) is one of the most common microvascular complications of type 2 diabetes mellitus (T2DM). It is multifactorial with the contribution of multiple genetic factors. We questioned the association of polymorphisms in the peroxisome proliferator-activated receptor ?2 (PPAR?2) gene (Pro12Ala and C161T) with DR in an Egyptian population. Methods: This case control study included one hundred healthy individuals and 252 T2DM among them 122 with DR and 130 without DR. Genotyping was done by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP). Results: The Pro12Ala Ala allele was associated with decreased risk of DR with an odds ratio (OR) of 0.484, 95% confidence interval (CI) (0.254 - 0.920), and a p value = 0.024. The C161T T allele was associated with increased risk of DR with OR = 2.593, 95% CI (1.672 - 4.020), p < 0.001. However, when considering other covariates such as glycosylated hemoglobin (HbA1c) in multivariate regression analysis only C161T was associated with increased risk of DR with OR = 3.479, 95% CI (1.907 - 6.346), p < 0.001, while the significant association with Pro12Ala was lost. HbA1c was higher in Pro/Pro genotype when compared to those with Ala/Ala and Pro/Ala genotypes. Conclusion: We report that T allele of C161T increased risk of DR in the studied population. Further studies are warranted to investigate functional implications of polymorphisms of the PPAR-? gene in DR development.

MicroRNA signature in patients with hepatocellular carcinoma associated with type 2 diabetes

BACKGROUND Nonalcoholic steatohepatitis-related cirrhosis is one of the liver complications in type 2 diabetes mellitus(T2DM)and reported to be a risk factor for developing hepatocellular carcinoma(HCC).A reliable screening biomarker of liver cirrhosis(LC)and HCC among T2DM patients is important to reduce the morbidity and mortality of this disease.MicroRNA(miRNA)is considered a key player in HCC and T2DM,and it might be a hidden culprit in diabetes-associated HCC,making it a promising reliable prognostic tool.AIM To investigate the signature of serum miRNAs as early biomarkers for the screening of HCC among diabetic patients.METHODS Expression profiles of miRNAs in serum samples of diabetic LC and diabetic HCC patients were assessed using Illumina sequencing;then,RT-qPCR was used to validate significantly altered miRNAs between the two groups.Candidate miRNAs were tested in serum samples of 200 T2DM patients,270 LC patients,200 HCC patients,and 225 healthy control subjects.Additionally,receiver operating characteristic(ROC)analysis,with area under the curve(AUC),was performed to assess the diagnostic performance of the screened miRNAs for discriminating HCC from LC and nonmalignant patients(LC+T2DM).RESULTS Expression of the sequenced miRNAs in serum was different in HCC vs LCpositive T2DM patients.Two miRNAs(miR-34a,miR-221)were significantly upregulated and five miRNAs(miR-16,miR-23-3p,miR-122-5p,miR-198,miR-199a-3p)were significantly down-regulated in HCC compared to LC patients.Analysis of ROC curve demonstrated that the combination of these seven miRNAs can be used as a reliable biomarker for detection of HCC in diabetic patients,as it could identify HCC with high diagnostic accuracy in diabetic LC patients(AUC=0.993)and in diabetic nonmalignant patients(AUC=0.961).CONCLUSION This study validates a panel of serum miRNAs that can be used as a reliable noninvasive screening biomarker of HCC among T2DM cirrhotic and noncirrhotic patients.The study recommends further research to shed light on a possible role of c-Met in T2DM-associated HCC via the miRNA regulatory pathway.