Patients with type 2 diabetes and prior appearance of thyroid disease required insulin therapy significantly earlier (median insulin-free period: 2.5 yrs; Q1 = 0.0, Q3 = 8.25) compared to patients who had thyroid dysfunction after diabetes onset (median insulin-free period: 8.0 yrs; Q1 = 3.0, Q3 = 12.0; p < 0.001). Here, INS is linked to type 2 diabetes mellitus.