Glycated haemoglobin was 6,7 ± 1,4; 95%CI: 5,41–6,23 in T1DM and 6,9 ± 1,4; 95%CI: 5,48–6,09 in T2DM, both in AA genotype of SOD1 gene and 6,59 ± 1,22, 95%CI: 5,08–6,24 in T1DM and 6,61 ± 1,51; 95%CI: 5,02–6,05 in T2DM, both in CC genotype of SOD1 gene, with p = 0,124. This evidence concerns the gene SOD1 and type 2 diabetes mellitus.