Role of NQO1 Gene Involvement and Susceptibility of T2DM Among Saudi Arabia Population

NQO1 disruption enhances susceptibility to oxidative stress during hyperglycemia and is a significant contributor to the development and progression of diabetes. Oxidative stress has been linked to several symptoms, including hyperglycemia, reactive oxygen species buildup, high blood pressure, and the expression of inflammatory markers. Therefore, the present research aimed to evaluate the genetic abnormality of NQO1 (rs1800566, C609T) gene polymorphism, expression, and vitamin-D level assessment among Type 2 diabetes mellitus (T2DM) patients. The study included 100 newly diagnosed T2DM cases and 100 healthy individuals as healthy controls. Total RNA was extracted from the whole blood using the TRIzol method, and further cDNA was synthesized, and expression was evaluated. There is a significant difference in NQO1 (rs1800566, C609T) genotype distribution among the T2DM patients and healthy controls (p = 0.04). Compared with the NQO1 CC wild-type genotype, the NQO1 CT heterozygous genotype had an odds ratio of 1.96 (1.08-3.55), and the NQO1 TT mutant type genotype had an odds ratio of 3.31 (0.61-17.77). Significantly decreased expression of NQO1 mRNA was observed with heterozygous CT (p < 0.0001) and homozygous mutant TT genotype (p = 0.0004), compared with homozygous wild-type CC genotype. NQO1 mRNA expression level was also compared with vitamin D levels among the T2DM patients. T2DM patients with vitamin D deficiency had 1.83-fold NQO1 mRNA expression, while vitamin D insufficient and sufficient T2DM cases had 3.31-fold (p < 0.0001) and 3.70-fold (p < 0.0001) NQO1 mRNA expression. It was concluded that NQO1 (rs1800566, C609T) CT and TT genotypes played a significant role in the worseness of type II diabetes mellitus, and decreased expression of NQO1 mRNA expression could be an essential factor for disease worseness as well as hypermethylation could be a factor for reduced expression leading to disease severity. The decreased NQO1 mRNA expression with heterozygous CT and mutant TT genotype associated with vitamin D deficiency may contribute to disease progression.