GSTM1 and type 2 diabetes mellitus: With respect to the GSTM1 polymorphism, it was observed that despite the fact that it did not have T2DM susceptibility, this isoform null genotype was associated with significantly increased levels of fasting blood glucose (p = 0.048), glycated hemoglobin (0.023) and blood pressure, both systolic (p<0.0001) and diastolic (p<0.0001) when compared to the present genotype in diabetic individuals (Table 5).