To evaluate if the concentrations of FGF19, VEGF and sklotho correspond to the degree of metabolic control, the group of T1D patients was divided according to the levels of HbA1c: HbA1c < 7.5% (group 1, N = 19), HbA1c 7.5-11.0% (group2, N = 26) and HbA1c > 11.0% (group3, N = 21). Here, FGF19 is linked to type 1 diabetes mellitus.