INS and type 1 diabetes mellitus: Maintained endogenous insulin production in patients with type 1 diabetes (T1D) is associated with better metabolic control and a lower prevalence of adverse events, including hypoglycemia, ketoacidosis and micro-vascular complication (Sjöberg et al. 1987; Steffes et al. 2003; Madsbad et al. 1986; Lachin et al. 2014; Madsbad et al. 1979).