Studies found a negative correlation between perceived health and Hb A1c, as well as between a sense of coherence and Hb A1c in adolescents with T1DM, suggesting that better self-perception and sense of coherence are associated with better glycemic control [26] and that higher Hb A1c was observed in overweight/obese participants who were also at higher risk of disordered eating [31]. This evidence concerns the gene GSTM1 and type 1 diabetes mellitus.