The non-obese of T/T genotype (rs4880) showed higher values of glucose concentration (p ≈ 0.0326), insulin concentration (p ≈ 0.0369) and HOMA-IR index (p ≈ 0.0306), compared to individuals of C/C or C/T genotype, indicating a possible association of rs4880 (SOD2) with the state of obesity and insulin resistance. This evidence concerns the gene INS and obesity due to melanocortin 4 receptor deficiency.